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Sample records for weed solanum americanum

  1. Estimativa da área foliar de plantas daninhas: Solanum americanum Mill Leaf area determination of weeds: Solanum americanum Mill

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    Gustavo R. Tofoli

    1998-12-01

    Full Text Available A maria pretinha (Solanum americanum Mill é uma planta daninha infestante de diversas culturas e além da competição pode causar outros problemas. Nos estudos envolvendo a biologia e o controle de plantas daninhas, a área foliar é uma das mais importantes características a serem avaliadas, mas tem sido pouco estudada porque sua determinação exige equipamentos sofisticados ou utiliza técnicas destrutivas. Visando obter equações que permitissem a estimativa da área foliar desta planta daninha utilizando características lineares do limbo foliar, facilmente mensuráveis em plantas no campo, foram estudadas correlações entre a área foliar real e as seguintes características das folhas: comprimento ao longo da nervura principal (C, largura máxima do limbo (L e o produto (C x L. Para tanto, foram mensuradas 200 folhas coletadas de plantas sujeitas às mais diversas condições ecológicas em que a espécie sobrevive, considerando-se todas as folhas das plantas desde que não apresentassem deformações oriundas de fatores, tais como, pragas, moléstias e granizo. Todas as equações, lineares simples, geométricas e exponenciais, permitiram boa estimativa da área foliar (Af da maria pretinha. Do ponto de vista prático, sugere-se optar pela equação linear simples envolvendo o produto (C x L, a qual apresentou o menor QM Resíduo. Assim, a estimativa da área foliar de S. americanum pode ser efetuada pela equação AF = 0,5632 x (C x L, com coeficiente de determinação (R2 de valor igual a 0,9516.Solanum americanum is a very aggressive weed that, besides competition, can cause many other problems. Despite being one of the most important parameters to be analyzed, only few studies have been carried out concerning the leaf area mainly because its determination demands sophisticated equipment or destructive techniques. Aiming to develop equations that allow to estimate the leaf area of this weed using linear measure of the leaf

  2. Estudos anatômicos de folhas de plantas daninhas: I - Nicandra physaloides, Solanum viarum, Solanum americanum e Raphanus raphanistrum Anatomical studies of weed leaves: I - Nicandra physaloides, Solanum viarum, Solanum americanum and Raphanus raphanistrum

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    E.A. Ferreira

    2002-08-01

    Full Text Available O objetivo deste trabalho foi estudar a anatomia das folhas das espécies de plantas daninhas Nicandra physaloides (joá-de-capote, Solanum viarum (joá-bravo, Solanum americanum (maria-pretinha e Raphanus raphanistrum (nabiça, visando obter melhor entendimento sobre as barreiras que cada espécie impõe à penetração dos herbicidas. Folhas completamente expandidas do terceiro ao quinto nó foram coletadas de plantas de ocorrência espontânea no campo. Das folhas de cada espécie foram obtidas três amostras da região central mediana, com aproximadamente 1 cm², as quais foram utilizadas em estudos da estrutura, clarificação e nas observações em microscópio eletrônico de varredura (MEV. Todas as espécies avaliadas são anfiestomáticas. O principal obstáculo foliar à penetração de herbicidas constatado em N. physaloides foi a alta densidade tricomática. Já em relação a S. viarum, baixa densidade estomática na face adaxial, alta densidade tricomática, presença de placas de cera epicuticular e grande espessura das cutículas foram as principais barreiras detectadas. S. americanum apresentou como principais obstáculos foliares à penetração de herbicidas a baixa densidade estomática na face adaxial e a grande espessura da cutícula da face adaxial, sendo esta última a única barreira constatada nas folhas de R. raphanistrum.This research aimed to study the leaf anatomy of the weed species Nicandra physaloides, Solanum viarum, Solanum americanum and Raphanus raphanistrum to acquire a better understanding of the barriers each species imposes upon herbicide penetration. Completely expanded leaves from the third to the fifth node were collected from plants spontaneously occurring in field. Three samples, with approximately 1 cm², were taken at the central portion of the leaves in each species. These samples were used in structural studies, clarification and observation using a scanning-electron microscope (SEM. All species

  3. Solanum americanum: reservoir for Potato virus Y and Cucumber mosaic virus in sweet pepper crops

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    Monika Fecury Moura

    2014-03-01

    Full Text Available Weeds can act as important reservoirs for viruses. Solanum americanum (Black nightshade is a common weed in Brazil and samples showing mosaic were collected from sweet pepper crops to verify the presence of viruses. One sample showed mixed infection between Cucumber mosaic virus (CMV and Potato virus Y (PVY and one sample showed simple infection by PVY. Both virus species were transmitted by plant extract and caused mosaic in tomato (Solanum lycopersicum cv. Santa Clara, sweet pepper (Capsicum annuum cv. Magda, Nicotiana benthamiana and N. tabaccum TNN, and local lesions on Chenopodium quinoa, C. murale and C. amaranticolor. The coat protein sequences for CMV and PVY found in S. americanum are phylogenetically more related to isolates from tomato. We conclude that S. americanum can act as a reservoir for different viruses during and between sweet pepper crop seasons.

  4. AFLP markers support separation of Solanum nodiflorum from Solanum americanum sensu stricto (Solanaceae)

    NARCIS (Netherlands)

    Manoko, M.L.K.; Berg, R.G. van den; Feron, R.M.C.; Weerden, G.M. van der; Mariani, C.

    2007-01-01

    This study was aimed at examining the relationships between the African material of Solanum americanum (also designated as S. nodiflorum), accessions of this taxon from other geographical areas, and American S. americanum using AFLP markers. 96 individuals representing 39 accessions of S. americanum

  5. AFLP markers support separation of Solanum nodiflorum from Solanum americanum sensu strictio (Solanaceae)

    NARCIS (Netherlands)

    Manoko, M.L.K.; Berg, van den R.G.; Feron, R.M.C.; Weerden, van der G.M.; Mariani, C.

    2007-01-01

    This study was aimed at examining the relationships between the African material of Solanum americanum (also designated as S. nodiflorum), accessions of this taxon from other geographical areas, and American S. americanum using AFLP markers. 96 individuals representing 39 accessions of S. americanum

  6. Aplicação de modelos múltiplos na determinação de níveis de prejuízo para a interação Solanum americanum e tomate de indústria Evaluation of economic levels for the Solanum americanum x tomato crop interaction using multiple models

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    J.M Portugal

    2011-12-01

    Full Text Available Este estudo apresenta um conceito unificador, que conjuga as teorias de densidade crítica e período crítico. Hipotetiza-se que não existe um valor fixo para a densidade crítica e para o período crítico, mas que os seus valores são interdependentes. A demonstração dessa hipótese é fundamentada em estudos de interferência entre Solanum americanum e o tomateiro. Aos resultados da produção de cinco ensaios, aplicaram-se modelos múltiplos de regressão, tendo como variáveis independentes a densidade e o número de dias de convivência entre a infestante e a cultura. A aplicação do Nível de Tolerância (NT à representação gráfica num plano das equações estimadas a partir de modelos múltiplos permite responder à questão: Quanto tempo pode permanecer uma determinada infestação de Solanum americanum sem causar prejuízo na cultura do tomateiro? É ainda possível verificar que a variação dos custos do controle e dos preços da cultura faz variar o NT e, concomitantemente, o tempo admissível, sem causar prejuízo, do Solanum americanum na cultura do tomateiro.This study introduces a unifying concept combining the theory of critical density and critical period of weed infestation. It is hypothesized that these two periods are interdependent, rather than fixed values. The hypothesis is based on studies of interference between Solanum americanum and the tomato crop. Multiple regression models were applied to the results of five field trials. The independent variables were density and number of days of weed and culture cohabitation. Applying the Tolerance Level (TL to the graphic representation (2D of the equations estimated from multiple non-linear models allowed answering the following question: how long does a particular infestation of Solanum americanum remain without causing injury to the tomato crop? It was also possible to conclude that the variation of control costs and crop prices changes the TL values, concomitantly

  7. Determination of trans-resveratrol in Solanum americanum Mill. by HPLC.

    Science.gov (United States)

    Vagula, Julianna Matias; Bertozzi, Janksyn; Castro, Juliana Cristina; Oliveira, Claudio Celestino de; Clemente, Edmar; Santos Júnior, Oscar de Oliveira; Visentainer, Jesuí Vergilio

    2016-10-01

    Solanum americanum Mill. is a plant that belongs to the Solanaceae family, its respective ripe fruit is dark purple. Ripe S. americanum Mill. fruits were submitted to physicochemical characterisation, and their trans-resveratrol contents were quantified by high-performance liquid chromatography. Such determination was executed with fruits at different stages of ripeness and freeze-stored fruits as well. In natura ripe fruit pulp and peel presented average trans-resveratrol amounts of 1.07 and 0.7960 μg per gram of sample, respectively. These amounts are significantly higher when compared to freeze-stored fruit (0.1353 μg of trans-resveratrol per gram of sample) and to other berries. All ripe fruits showed significant amounts of total anthocyanins and total antioxidants. Thus, for the first time, trans-resveratrol has been identified and quantified in S. americanum Mill. fruit samples.

  8. Acúmulo de massa seca e de macronutrientes por plantas de Glycine max e Solanum americanum Accumulation of dry mass and macronutrients by Glycine max and Solanum americanum plants

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    S. Bianco

    2012-03-01

    S.Soybean is one of the main crops in Brazil, but its productivity is very affected by weed competition. Two experiments were carried out in Jaboticabal, SP, Brazil, under greenhouse conditions to determine the accumulation and distribution of dry mass and macronutrients in soybean cv. BR-16, from October 2000 to February 2001, and Solanum americanum plants, from January to May 1995. Plants were grown in seven liter pots filled with river sand substrate and were daily irrigated with nutrient solution. The treatments were constituted by the times of samplings carried out at 14 day intervals, starting 21 days after emergence (DAE. Soybean evaluation was extended to 161 DAE, while S. americanum was extended to 119 DAE. The point of maximum theoretical accumulation of dry mass in soybean occurred at 104 DAE (35.00 g per plant while for S. americanum, it occurred at 143 DAE (179.62 g per plant. From emergence until 49 and 63 DAE, leaves showed higher participation in dry mass accumulation of soybean and S. americanum, respectively. After these periods, an inversion could be observed, with leaves being surpassed by stems for the weeds, and by stems and later, by reproductive structures, for the crop. Macronutrient uptake rate reached higher values between 69 to 87 DAE for soybean and between 105 to 119 DAE for S. americanum. Considering the mean inflexion point values observed in soybean crop, at 75 DAE, it can be evidenced that one soybean plant theoretically accumulated 23.90 g of dry mass, 564.40 mg of N, 7.10 mg of P, 490.80 mg of K, 487.00 mg of Ca, 156.60 mg of Mg and 36.00 mg of S, while one S. americanum plant theoretically accumulated 33.75 g of dry mass, 875.96 mg of N, 88.46 mg of P, 983.54 mg of K, 647.60 mg of Ca, 100.93 mg of Mg, and 42.15 mg of S.

  9. The Characterization of SaPIN2b, a Plant Trichome-Localized Proteinase Inhibitor from Solanum americanum

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    Zeng-Fu Xu

    2012-11-01

    Full Text Available Proteinase inhibitors play an important role in plant resistance of insects and pathogens. In this study, we characterized the serine proteinase inhibitor SaPIN2b, which is constitutively expressed in Solanum americanum trichomes and contains two conserved motifs of the proteinase inhibitor II (PIN2 family. The recombinant SaPIN2b (rSaPIN2b, which was expressed in Escherichia coli, was demonstrated to be a potent proteinase inhibitor against a panel of serine proteinases, including subtilisin A, chymotrypsin and trypsin. Moreover, rSaPIN2b also effectively inhibited the proteinase activities of midgut trypsin-like proteinases that were extracted from the devastating pest Helicoverpa armigera. Furthermore, the overexpression of SaPIN2b in transgenic tobacco plants resulted in enhanced resistance against H. armigera. Taken together, our results demonstrated that SaPIN2b is a potent serine proteinase inhibitor that may act as a protective protein in plant defense against insect attacks.

  10. The characterization of SaPIN2b, a plant trichome-localized proteinase inhibitor from Solanum americanum.

    Science.gov (United States)

    Luo, Ming; Ding, Ling-Wen; Ge, Zhi-Juan; Wang, Zhen-Yu; Hu, Bo-Lun; Yang, Xiao-Bei; Sun, Qiao-Yang; Xu, Zeng-Fu

    2012-11-16

    Proteinase inhibitors play an important role in plant resistance of insects and pathogens. In this study, we characterized the serine proteinase inhibitor SaPIN2b, which is constitutively expressed in Solanum americanum trichomes and contains two conserved motifs of the proteinase inhibitor II (PIN2) family. The recombinant SaPIN2b (rSaPIN2b), which was expressed in Escherichia coli, was demonstrated to be a potent proteinase inhibitor against a panel of serine proteinases, including subtilisin A, chymotrypsin and trypsin. Moreover, rSaPIN2b also effectively inhibited the proteinase activities of midgut trypsin-like proteinases that were extracted from the devastating pest Helicoverpa armigera. Furthermore, the overexpression of SaPIN2b in transgenic tobacco plants resulted in enhanced resistance against H. armigera. Taken together, our results demonstrated that SaPIN2b is a potent serine proteinase inhibitor that may act as a protective protein in plant defense against insect attacks.

  11. Efeito de doses de adubo 4-14-8 na competição entre tomateiro e Solanum americanum em convivência intra e interespecífica Effect of fertilizer 4-14-8 doses on competition between tomato and Solanum americanum under intra- and inter-specific coexistence

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    B.P. Silva

    2010-01-01

    Full Text Available O tomateiro (Lycopersicum esculentum é uma das mais importantes hortaliças produzidas no mundo, porém sua produtividade pode ser reduzida em função da convivência com Solanum americanum (maria-pretinha. O objetivo desta pesquisa foi avaliar o efeito da adubação na relação de interferência intra e interespecífica entre plantas de tomateiro e S. americanum. Duas plantas em condições de convivência intra e interespecífica, por espécie, foram plantadas em vasos e adubadas com 13, 18 e 24 g de 4-14-8 por vaso, sendo avaliadas características de crescimento de ambas as espécies aos 90 dias após o transplante das plantas. A adubação com 4-14-8 estimulou o desenvolvimento da área foliar e da massa seca de caules, folhas e frutos de S. americanum, além da área foliar e da massa seca de folhas e frutos do tomateiro. A convivência interespecífica proporcionou maior altura de plantas de S. americanum, bem como menor altura e massa seca de folhas e frutos do tomateiro. Houve interação dos fatores adubação e convivência somente para o tomateiro, sendo a altura e a massa seca de folhas da cultura influenciadas negativamente quando submetidas às maiores doses de adubo e à competição com S. americanum.Tomato (Lycopersicum esculentum is one of the leading vegetable crops grown worldwide, but its productivity may be reduced due to coexistence with Solanum americanum (black nightshade. This work aimed to evaluate the effect of fertilization on intra- and inter-specific interference between tomato and S. americanum plants. Two plants in intra- and inter-specific coexistence conditions of both species were planted in pots and fertilized with 13, 18 and 24 g of 4-14-8 per pot to evaluate the growth characteristics of both species at 90 days after transplanting. The 4-14-8 fertilization stimulated the development of the leaf area and dry mass of stems, leaves and fruit of S. americanum, consequently and equally influencing the leaf

  12. Dual high-resolution inhibition profiling and HPLC-HRMS-SPE-NMR analysis for identification of α-glucosidase and radical scavenging inhibitors in Solanum americanum Mill

    DEFF Research Database (Denmark)

    Silva, Eder Lana e; Almeida-Lafetá, Rita C.; Borges, Ricardo Moreira

    2017-01-01

    Solanum americanum is one of the most prominent species used to treat type 2 diabetes in Guatemala. In our ongoing efforts to find antidiabetic and antioxidative compounds from natural sources, an ethyl acetate extract of this medicinal herb was investigated using dual high-resolution α......-glucosidase/radical scavenging inhibition profiling. The high-resolution biochromatograms obtained by this technique were used to target subsequent structural elucidation by HPLC-HRMS-SPE-NMR analysis towards the bioactive constituents. This led to identification of 4-hydroxybenzoic acid ( 1 ) and 3-indolecarboxylic acid ( 6...

  13. The influence of non-living mulch, mechanical and thermal treatments on weed population and yield of rainfed fresh-market tomato (Solanum lycopersicum L.

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    M. Fontanelli

    2013-06-01

    Full Text Available Weed control is often a major limitation for vegetable crops, since compared to arable crops fewer herbicides are available and the crops are more sensitive to weeds. Field experiments were carried out in the province of Pisa (Central Italy to determine the effect of two different mulches (black biodegradable plastic film and wheat straw and mechanical and thermal treatments on weed population and yield of rain-fed fresh market tomato (Solanum lycopersicum L.. Rolling harrow, flaming machine and precision hoe for weed control, which were either built, enhanced or modified by the University of Pisa were used separately (mechanical-thermal strategy or in combination with a straw mulch (mechanical-thermal-straw strategy. These two innovative strategies were compared with the traditional farming system, which uses a biodegradable plastic mulch film. The strategies were compared in terms of machine performance, weed density, total labour requirement, weed dry biomass, and crop fresh yield at harvest. The total operative time for weed control was on average ~25 h ha-1 for the two systems, which included mulching, and over 30 h ha-1 for the mechanical-thermal strategy. The three strategies controlled weeds effectively, with only 30 g m-2 in each treatment. Tomato yield, however, was 35% higher for strategies that included mulching (both biodegradable film and straw.

  14. Solanum nigrum L. weed plants as a remediation tool for metalaxyl-polluted effluents and soils.

    Science.gov (United States)

    Teixeira, Jorge; Sousa, Alexandra de; Azenha, Manuel; Moreira, José Tiago; Fidalgo, Fernanda; Fernando Silva, A; Faria, Joaquim L; Silva, Adrián M T

    2011-10-01

    In this work, the phytoremediation potential of metalaxyl, a commonly used persistent, mobile and leachy fungicide, by Solanum nigrum L. plants was studied. The study revealed that this plant species can be used as an excellent metalaxyl phytoremediation tool, thus providing a cost effective and environmentally friendly clean technology for the decontamination of sites and effluents. As it can be sowed directly in the remediation site, is able to complete its life cycle without suffering major stress. Because it accumulates high amounts of the fungicide in the aboveground tissues, enables its concentration and proper disposal by cutting off the corresponding plant part. The study also suggests that the tolerance to metalaxyl is due to a suitable antioxidant response comprising proline accumulation and guaiacol peroxidase and glutathione-S-transferase enhanced activities, that reduce oxidative damage to the plant organs. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Evaluation of weeds as possible hosts of the potyviruses associated with tree tomato (Solanum betaceum Cav. viroses

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    Sierra S. Adela

    2012-04-01

    Full Text Available

    To determine possible weed hosts of potyviruses associated with the disease known as “tree tomato virus disease” in Antioquia department (Colombia, a sampling was conducted to identify weed species commonly found in commercial crops of S. betaceum affected by the virus and the possible presence of the virus in these plants. The encountered weed species were grouped into seven different taxonomic families, within which we evaluated the ten most common species. The selected weeds, three indicator species of the virus and tree tomato plants were grown in a greenhouse and mechanically inoculated with an extract of infected tree tomato tissue. One month after inoculation, the tree tomato plants and Nicotiana tabacum showed symptoms of the disease and were serologically positive, whereas none of the weeds showed symptoms or were positive for potyviruses serology. In order to confirm that the detection of the virus was not caused by low viral titers that did not reach the minimum detection level of the test used, the tomato tree plants were reinoculated with an extract of sap from the studied weeds and potyviruses was not detected in any of the tested weeds and therefore cannot be considered, with the utilized methodology, as hosts for the potyviruses affecting tree tomato plants.

  16. 外来入侵杂草刺萼龙葵%Alien invasive weed -Solanum rostratum Dun

    Institute of Scientific and Technical Information of China (English)

    车晋滇; 刘全儒; 胡彬

    2006-01-01

    2003年北京首次发现外来入侵杂草刺萼龙葵(Solanum rostratum Dunal.).2005年在北京顺义区试验地进行了刺萼龙葵生育期观察,并在北京延庆县野外自然群落中随机取样带回室内测定.本文对其形态特征、生物学特性、分布及危害进行了叙述.

  17. 重要检疫性杂草刺萼龙葵分子生物学检测的研究%Study on molecular detection of quarantine weed Solanum rostratum

    Institute of Scientific and Technical Information of China (English)

    刘勇; 廖芳; 杨秀丽; 刘鹏; 牛春敬; 黄国明

    2011-01-01

    Solanum rostratum Dunal belonging to genus Solanum L. , is a quarantine weed being banned access to China. This paper selected 5 species with similar morphologic characters of seeds. Through analysis of the difference of DNA sequences of GBSSI gene, a set of specific primers were designed for the PCR detection of the genomic DNA of Solanum rostratum. The stable and credible molecular detection method has been successfully established, and the detection duration is one day to finish the whole process. The establishment of this detection method would strongly promote the quarantine of plant weeds.%刺萼龙葵属于茄属植物,是我国规定禁止进境的检疫性有害杂草.选取与刺萼龙葵种子形态非常近似的同科5种植物为研究对象,依据茄科植物GBSSI基因序列差异,设计刺萼龙葵的特异PCR引物SRSF1/SRSR1,扩增片段约为500bp,用于对刺萼龙葵的特异检测.本研究建立了刺萼龙葵快速简便、稳定可靠的分子生物学检测方法,一个工作日内完成检测.

  18. Solanum (Solanaceae in Uganda

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    Z. R. Bukenya

    1995-12-01

    Full Text Available Of the 41 species, subspecies and cultivar groups in the genus Solanum L. (Solanaceae that occur in Uganda, about 30 are indigenous. In Uganda several members of the genus are utilised as food crops while others are put to medicinal and ornamental use. Some members are notorious weeds. A key to the species and descriptions of all Solanum species occurring in Uganda are provided.

  19. Caracterização morfológica das sementes e plântulas de seis espécies invasoras do gênero Solanum L Seed and seedling morphology of six weedy species of Solanum L

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    Doris Groth

    1989-07-01

    Full Text Available As sementes do gênero Solarium L. são relativamente muito semelhantes, no entanto, a associação de características morfológicas externas da semente com as características anatômicas, como a forma do hilo, a textura e o tipo de esculturas da superfície do tegumento, bem como a forma do embrião curvo (circulado ou espiralado, são características da maior importância na identificação taxonómica à nível de espécie. São apresentadas ilustrações, chaves dicotômicas e descrições morfológicas do gênero Solarium e descrição detalhada das plántulas e das sementes de Solanum aculeatissimum Jacq., S. americanum Mill., S, ciliatum Lam., S. sisymbriifolium Lam., S. sordidum Sendt. e S. viarum Dunal. São apresentados, também, o nome vulgar, o tipo de reprodução e disseminação, as culturas nas quais é considerada invasora e as sementes agrícolas onde ocorre como "impureza".Morphological caracterization of the seeds and seedlings of six weed especies of the genus Solanum L. The seeds of the genus Solanum are very similar, however, the association of their external characteristics with the anatomical features, such as hilum shape, the texture and the type of the seed coat sculptures, as well as the curved (circulated or coiled shape of the embryo, are parameters of great importance in the taxonomical identification at the species level. It is are presented the morphological descriptions of the genus Solanum and a more detailed description of each studied species in terms of seed and seedling structures, including illustrations and taxonomical keys for the identification of Solanum aculeatissimum Jacq., S. americanum Mill., S. ciliatum Lam., S. sisymbriifolium Lam., S. sordidum Sendt. e S. viarum Dunal. There are also indications of the common names, the type of reproduction and dispersion, the crops in which the species is considered as a weed and the agricultural seeds in which it is found as a weed seed.

  20. Purification and characters' analysis of specific proteinase inhibitorⅡ from phloem of Solanum americanum%龙葵韧皮部特异Ⅱ型蛋白酶抑制剂的分离纯化和部分特性分析

    Institute of Scientific and Technical Information of China (English)

    王震宇; 李佳

    2010-01-01

    龙葵蛋白酶抑制剂Ⅱa(Solanum americanum proteinase inhibitor Ⅱa,SaPIN2a)基因是第一个被发现在植物韧皮部中特异表达的蛋白酶抑制剂Ⅱ(PIN2)基因.以野生型龙葵的茎为材料,经过粉碎→浸提→超滤→(NH4)SO4沉淀→分子排阻层析→离子交换层析→胰蛋白酶亲和层析一系列的处理后,分离纯化得到一个丝氨酸蛋白酶抑制剂,SDS-PAGE结果显示其表观分子量约为20 kDa.对该纯化的丝氨酸蛋白酶抑制剂进行了蛋白质测序工作.结果得到该蛋白N端23个氨基酸残基的序列为:KACTRECGHFSYGICPRSEGSPQ,经过Blast比对分析发现这23个氨基酸残基为成熟型SaPIN2a(即不含信号肽的SaPIN2a)N端序列.

  1. Cytotoxic Compounds from Zanthoxylum Americanum

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Four pyranocoumarins: dipetaline, alloxanthoxyletin, xanthoxyletin, and xanthyletin, and two lignans: sesamin and asarinin were isolated from the northern prickly ash, Zanthoxylum americanum. To varying degrees, all six compounds inhibited the incorporation of tritiated thymidine into human leukemia (HL-60) cells and the inhibitory effect was dependent on the structures of the isolated compounds.

  2. Tropical Soda Apple (Solanum viarum)

    Science.gov (United States)

    Tropical soda apple (Solanum viarum Dunal), a perennial shrub, is a Federal Noxious Weed that continues to spread at an alarming rate in the southeastern United States. Information is provided on the impact of tropical soda apple on agricultural and natural areas, federal regulations for restricted...

  3. Tomato spotted wilt virus (TS WV, weeds and thrip vectors in the tomato (Solanum lycopersicum L. in the Andean region of Cundinamarca (Colombia

    Directory of Open Access Journals (Sweden)

    Everth E Ebratt R

    2013-04-01

    Full Text Available The presence and distribution of the TSWV, weeds and thrip vectors in major tomato producing areas in the Andean department of Cundinamarca (Oriente, Sumapaz and Ubate provinces were assessed with the DAS ELISA technique, evaluating the presence of the TSWV in tomato tissue, associated thrips and weeds. High incidences were observed in different provinces of the Andean department of Cundinamarca. The average viral incidence reached 23.3% in Sumapaz, 19.4% in Oriente and 4% in Ubate. The symptoms observed were: brown spots and concentric rings in the leaf area, stems and fruits; browning and spotting in the flower; and wilting in the leaves, stems and flowers. The thrip species with the highest presence were Frankliniella occidentalis, followed by Thrips palmi and Thrips tabaci. We determined the important role of weeds as inoculum sources and vector reservoirs for the species Emilia sonchifolia and Amaranthus dubius

  4. Effect of Dose and Oxadiargyl Application Time at the Different Growth Stages on Weed Biomass and Tuber Yield of Potato (Solanum tuberosum L.

    Directory of Open Access Journals (Sweden)

    E. Samadi Kalkhoran

    2016-01-01

    Full Text Available To evaluate the effects of dose and application time of oxadiargyl, as a postemergence herbicide, on weed biomass and tuber yield of potato, a factorial experiment based on randomized complete block design with 3 replications was conducted at Alaroog Research Station at the University of Mohaghegh-Ardabili in 2013. Treatments consisted of oxadiargyl dosages (0, 0.05, 0.1, 0.2, 0.4, 0.6 and 0.8 lit a.i /ha, and its time of applications at different potato growth stages (potato emergence, stolon initiation and potato tuber bulking, weed free treatment was considered as control. Statistical analysis showed that 0.8 lit a.i/ha of oxadiargyl reduced biomass of weed by 66.16 percent. Oxadiargyl application at emergence time resulted in highest percent reduction of weed biomass. Results, also, showed that application 0.8 lit a.i/ha of oxadiargyl, after weed free condition, increased number of seed tuber and total tuber yield by 82.16 and 51.59 percent respectively, but it reduced number of non seed tuber by 43.17 percent. Application of oxadiargyl at emergence time, as compared with the other application times, resulted in highest increase in the number of seed tuber and total tuber yield, but it did not affected number of non seed tubers. Interaction effect of dose by time of oxadiargyl application revealed that using 0.8 lit a.i/ha dose at potato emergence time increased number of edible tubers by 100%. It may be conducted that application of this dose at potato emergence time was highly efficient in controlling weeds and increasing potato tuber yield.

  5. Host-Parasite-Bacteria Triangle: The Microbiome of the Parasitic Weed Phelipanche aegyptiaca and Tomato-Solanum lycopersicum (Mill.) as a Host

    Science.gov (United States)

    Iasur Kruh, Lilach; Lahav, Tamar; Abu-Nassar, Jacline; Achdari, Guy; Salami, Raghda; Freilich, Shiri; Aly, Radi

    2017-01-01

    Broomrapes (Phelipanche/Orobanche spp.) are holoparasitic plants that subsist on the roots of a variety of agricultural crops, establishing direct connections with the host vascular system. This connection allows for the exchange of various substances and a possible exchange of endophytic microorganisms that inhabit the internal tissues of both plants. To shed some light on bacterial interactions occurring between the parasitic Phelipanche aegyptiaca and its host tomato, we characterized the endophytic composition in the parasite during the parasitization process and ascertained if these changes were accompanied by changes to endophytes in the host root. Endophyte communities of the parasitic weed were significantly different from that of the non-parasitized tomato root but no significant differences were observed between the parasite and its host after parasitization, suggesting the occurrence of bacterial exchange between these two plants. Moreover, the P. aegyptiaca endophytic community composition showed a clear shift from gram negative to gram-positive bacteria at different developmental stages of the parasite life cycle. To examine possible functions of the endophytic bacteria in both the host and the parasite plants, a number of unique bacterial candidates were isolated and characterized. Results showed that a Pseudomonas strain PhelS10, originating from the tomato roots, suppressed approximately 80% of P. aegyptiaca seed germination and significantly reduced P. aegyptiaca parasitism. The information gleaned in the present study regarding the endophytic microbial communities in this unique ecological system of two plants connected by their vascular system, highlights the potential of exploiting alternative environmentally friendly approaches for parasitic weed control. PMID:28298918

  6. Host-Parasite-Bacteria Triangle: The Microbiome of the Parasitic Weed Phelipanche aegyptiaca and Tomato-Solanum lycopersicum (Mill.) as a Host.

    Science.gov (United States)

    Iasur Kruh, Lilach; Lahav, Tamar; Abu-Nassar, Jacline; Achdari, Guy; Salami, Raghda; Freilich, Shiri; Aly, Radi

    2017-01-01

    Broomrapes (Phelipanche/Orobanche spp.) are holoparasitic plants that subsist on the roots of a variety of agricultural crops, establishing direct connections with the host vascular system. This connection allows for the exchange of various substances and a possible exchange of endophytic microorganisms that inhabit the internal tissues of both plants. To shed some light on bacterial interactions occurring between the parasitic Phelipanche aegyptiaca and its host tomato, we characterized the endophytic composition in the parasite during the parasitization process and ascertained if these changes were accompanied by changes to endophytes in the host root. Endophyte communities of the parasitic weed were significantly different from that of the non-parasitized tomato root but no significant differences were observed between the parasite and its host after parasitization, suggesting the occurrence of bacterial exchange between these two plants. Moreover, the P. aegyptiaca endophytic community composition showed a clear shift from gram negative to gram-positive bacteria at different developmental stages of the parasite life cycle. To examine possible functions of the endophytic bacteria in both the host and the parasite plants, a number of unique bacterial candidates were isolated and characterized. Results showed that a Pseudomonas strain PhelS10, originating from the tomato roots, suppressed approximately 80% of P. aegyptiaca seed germination and significantly reduced P. aegyptiaca parasitism. The information gleaned in the present study regarding the endophytic microbial communities in this unique ecological system of two plants connected by their vascular system, highlights the potential of exploiting alternative environmentally friendly approaches for parasitic weed control.

  7. Invasive Weed Species Buffalobur (Solanum rostratum) and its Risk Assessment%外来杂草刺萼龙葵及其风险评估

    Institute of Scientific and Technical Information of China (English)

    魏守辉; 张朝贤; 刘延; 黄红娟; 孟庆会; 崔海兰; 李香菊

    2007-01-01

    外来入侵生物已对世界各国的自然生态系统、农业生产及公众健康造成了严重危害.刺萼龙葵(Solanum rostratum)起源于北美洲,其繁殖和适应能力很强,是具有潜在危险的外来有害杂草.对刺萼龙葵的分布、生物生态学特性、经济和生态影响及其控制和管理措施等进行了系统综述.根据生物生态学特性、潜在危险及管理控制的难度等特点,对刺萼龙葵进行了风险评估,得出其风险值为86,属高度危险的检疫性有害生物.应当高度重视刺萼龙葵的入侵,积极采取措施控制其危害蔓延.

  8. RESEARCH AND PROSPECT OF INVASIVE WEED SOLANUM ROSTRATUM DUNAL%外来入侵植物刺萼龙葵的研究概况及展望

    Institute of Scientific and Technical Information of China (English)

    郭章碧; 张国良; 付卫东; 郑浩

    2011-01-01

    刺萼龙葵(Solanum rostratum Dunal)是世界性检疫杂草,原产北美洲,现已扩散至非洲、亚洲、大洋洲和太平洋群岛的大部分热带及亚热带地区,严重威胁着入侵地区植物的生长、生物多样性和生态安全.本文对国内外学者关于刺萼龙葵的研究文献进行了总结与归类,介绍了其生物生态学、化学成分及功效、入侵路线与机制、入侵危害性与防治措施等方面,并提出了展望,旨在对新外来人侵植物刺萼龙葵进行客观认识,制定科学的防治或者利用等策略提供理论依据.

  9. Morphological Variation among 23 Xiphinema americanum Populations.

    Science.gov (United States)

    Cho, M R; Robbins, R T

    1991-01-01

    Morphometrics of 23 United States populations of Xiphinema americanum sensu lato, sharing the characteristics of an offset lip region and conoid tail, were examined and analyzed statistically by canonical discriminant analysis (CDA). Specimens were collected from Arkansas, Georgia, Tennessee, Mississippi, Florida, Oklahoma, California, and North Dakota. Eleven measurements and body ratios obtained from female specimens were used in the analysis. Xiphinema americanum, X. bricolensis, X. californicum, X. citricolum, X, intermedium, X. tarjanense, and X. thornei, and one undescribed species were identified among the 23 populations. Three groups -- X. americanum-group, X. californicum-group, and X. intermedium-group (X. intermedium and X. tarjanense) -- were formed and four populations belonging to four different species were separated consistently from these groups in CDA scatterplots of the 23 populations. Composition of the groups was somewhat related to the geographical origins of the populations in the groups. A population from California had morphometrics intermediate between X. americanum and X. californicum. Separation between the X. americanum-group and X. californicum-group in the CDA scatterplots was not as distinct as that between them and the X. intermedium-group or between any of the three groups and the four single outlying populations.

  10. Agronomic Weeds.

    Science.gov (United States)

    Hartwig, Nathan L.

    This agriculture extension service publication from Pennsylvania State University examines agronomic weed problems and control. Contents include a listing of the characteristics of weeds, a section on herbicides, and a section on the important weeds of agronomic crops in Pennsylvania. The herbicide section discusses systemic herbicides, contact…

  11. Agronomic Weeds.

    Science.gov (United States)

    Hartwig, Nathan L.

    This agriculture extension service publication from Pennsylvania State University examines agronomic weed problems and control. Contents include a listing of the characteristics of weeds, a section on herbicides, and a section on the important weeds of agronomic crops in Pennsylvania. The herbicide section discusses systemic herbicides, contact…

  12. Efeitos dos períodos de competição do mato na cultura do amendoim: II. Safra das águas Effects of weed competition periods on peanut: II. Wet season crop

    Directory of Open Access Journals (Sweden)

    EDISON MARTINS PAULO

    2001-01-01

    Full Text Available O presente trabalho foi realizado na safra das águas de 1989, no Núcleo de Agronomia da Alta Paulista, em Adamantina (SP para estudar o efeito de diferentes períodos de competição do mato no amendoim. Adotou-se o delineamento estatístico de blocos ao acaso, com quatro repetições e 22 tratamentos. Os tratamentos resultaram da combinação da presença e da ausência do mato a partir do início da cultura, com as seguintes épocas de remoção da flora infestante: 0, 10, 20, 30, 40, 50, 60, 70, 80, 90 e 100 dias após a semeadura. As parcelas foram constituídas por quatro linhas de amendoim, perfazendo 6 m² de área útil. As principais plantas daninhas encontradas na área experimental foram: Cyperus lanceolatus Poir, Commelina benghalensis L., Brachiaria decumbens Stapf., Amaranthus viridis L., Eleusine indica (L. Gaertn., Portulaca oleracea L., Digitaria horizontalis Willd. e Solanum americanum Mill. A convivência do mato diminuiu a produção de vagens, de grãos e a população do amendoim na colheita. Não se observou efeito do mato sobre o rendimento de grãos e sobre a matéria seca acumulada pela parte aérea do amendoim. Capinas aplicadas aos 13 e 67 dias após a semeadura, respectivamente para os sistemas sem e com mato a partir da semeadura, foram suficientes para a obtenção de produção de vagens de amendoim estatisticamente igual à obtida pela cultura mantida sem competição, durante todo o ciclo. Os componentes da produção do amendoim foram favorecidos com a aplicação do sistema sem mato, a partir do início da cultura.The present research was carried out at the Núcleo de Agronomia da Alta Paulista, in Adamantina, State of Sao Paulo, Brazil, to study the effects of different periods of weed competition with peanut.The treatments were all possible combinations among the presence/absence of weeds (at the sowing time and the following periods of weed removal: 0, 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 days

  13. Effect of Cultural Practices in Night on Weed Density and Weed Dry Matter

    Directory of Open Access Journals (Sweden)

    M.H Rashed Mohasel

    2011-01-01

    Full Text Available Abstract In order to evaluate the response of weed seeds to light, two experiments, at two different locations were conducted at Ferdowsi university of Mashhad in 2009. At the first experiment, field was ploughed in day and night. Weed density was evaluated 70 d after plough, with 1×1 quadrate. At the second experiment, at night treatment, ploughing, potato planting and weeding with cultivator were done at night. Weed sampling was done twice at 43 and 130 days after planting with 1×1 quadrate and weeds were identified and counted. Result showed pigweed (Amaranthus retroflexus L., sowthistle (Sonchus oleraceus L., crabgrass (Digitaria sanguinalis (L. scop, jimsonweed (Datura stramonium L. and mallow (Hibiscus trionum L. did not observed at night plough, in contrast, night plough has no significance influence on common lambsquarters (Chenopodium album L., and black nightshade (Solanum nigrum L.. Only common lambsquarters had similar appearance in two treatments, indicating insusceptibility of this weed to time of plough. Interestingly, at the second experiment, result was very similar. Potato yield was higher at night treatment, but not significant. This research showed that some cultural practice like plough, planting and weeding with cultivator in night can reduce weed density and weed dry matter. Keywords: Germination, Time of plough, Sustainable weeds management, Light

  14. Estimating Time of Weed Emergence in Cucumber (Cucumis sativus L.

    Directory of Open Access Journals (Sweden)

    Nihat Tursun

    2015-02-01

    Full Text Available Modelling is carried out for eleven major weeds in cucumber to develop estimated models for weed emergence time. Weed species were grouped according to their emergence patterns. Amaranthus retroflexus, Chenopodium album, Heliotropium europaeum, Polygonum aviculare and Solanum nigrum were early emerging, Convolvulus arvensis, Cyperus rotundus, Cynodon dactylon, Portulaca oleracea and Sorghum halepense were season long emerging Tribulus terrestris was the late emerging weed species. Different non-linear growth curves (Chapman-Richard, Weibull, logistic, Gompertz and cubic spline fitted to the data of cumulative percent emergence for the different species and years. Cubic spline seemed the best model for many species.

  15. Weed suppression by green manure in an agroecological system

    Directory of Open Access Journals (Sweden)

    Katia Maria Garicoix Recalde

    2015-12-01

    Full Text Available ABSTRACT Green manure promotes efficient suppression of weeds, but green manure species can exhibit distinct behaviors, depending on the environmental conditions. This study aimed to evaluate the potential of soil mulching and weed suppression by spring/summer green manure species grown in the spring/summer season, at different growth stages and after management (cut, for 90 days during the cassava crop cycle. The study was carried out in the 2010/2011 season, in a system managed under agroecological principles. The treatments consisted of different green manure species and arrangements: Crotalaria juncea, Cajanus cajan, Canavalia brasiliensis, Canavalia ensiformis, Pennisetum americanum, Crotalaria juncea and Pennisetum americanum intercropped; Mucuna aterrima, Sorghum bicolor, a mixture of all the green manures in study and a control plot under fallow. The experiment was arranged in a randomized block design with four replications. The evaluations of the soil cover either by the green manures or weeds were performed at 45, 90 and 105 days after the emergence of the green manures. The cassava crop was planted under reduced tillage system at 11 days after the cut of the green manures. The percentage of soil covered by weeds and the dry matter produced were evaluated at 30, 60 and 90 days after planting. The results showed that the green manures had a suppressive effect on weeds during their life cycle, as well as during the first months after its management (cut, composing the mulch.

  16. Tropical soda apple mosaic virus Identified in Solanum capsicoides in Florida

    Science.gov (United States)

    Red soda apple (Solanum capsicoides All.), a member of the Solanaceae, is a weed originally from Brazil. It is a perennial in southern Florida and is characterized by abundant prickles on stems, petioles and leaves. Prickles on stems are more dense than on its larger noxious weed relative, tropica...

  17. Flowers & Weeds.

    Science.gov (United States)

    Flannery, Maura C.

    1996-01-01

    Describes the topics and teaching strategies employed in an Issues in Biology course. Discusses flowers, plant breeding, potatoes and tomatoes, the chocolate tree, weeds, Arabidopis, gene transfers, and plant genes/human genes. Contains 22 references. (JRH)

  18. Flowers & Weeds.

    Science.gov (United States)

    Flannery, Maura C.

    1996-01-01

    Describes the topics and teaching strategies employed in an Issues in Biology course. Discusses flowers, plant breeding, potatoes and tomatoes, the chocolate tree, weeds, Arabidopis, gene transfers, and plant genes/human genes. Contains 22 references. (JRH)

  19. Management of Solanum elaeagnifolium in the Mediterranean Basin

    Science.gov (United States)

    Solanum elaeagnifolium Cav. (silverleaf nightshade, SOLEL) is a prominent invasive alien weed in many countries of the Mediterranean Basin since its introduction in the mid-20th century, originating from the southwestern United States and northern Mexico. It reproduces vegetatively and by seeds that...

  20. Weeding Your Collection.

    Science.gov (United States)

    Kerby, Ramona

    2002-01-01

    Offers guidelines for weeding as part of school library collection development. Highlights include developing a weeding policy; and the CREW (Continuous Review Evaluation and Weeding) method, including reasons for weeding, scheduling, and guidelines for fiction and for nonfiction. (LRW)

  1. Host status of six major weeds to Meloidogyne chitwoodi and Pratylenchus penetrans, including a preliminary field survey concerning other weeds

    NARCIS (Netherlands)

    Kutywayo, V.; Been, T.H.

    2006-01-01

    A glasshouse experiment was carried out to investigate the host status of six important weeds in intensive agricultural cropping systems to Meloidogyne chitwoodi and Pratylenchus penetrans. Senecio vulgaris L., Capsella bursa-pastoris (L.) Medic. and Solanum nigrum L. were hosts of M. chitwoodi with

  2. Host status of six major weeds to Meloidogyne chitwoodi and Pratylenchus penetrans, including a preliminary field survey concerning other weeds

    NARCIS (Netherlands)

    Kutywayo, V.; Been, T.H.

    2006-01-01

    A glasshouse experiment was carried out to investigate the host status of six important weeds in intensive agricultural cropping systems to Meloidogyne chitwoodi and Pratylenchus penetrans. Senecio vulgaris L., Capsella bursa-pastoris (L.) Medic. and Solanum nigrum L. were hosts of M. chitwoodi with

  3. Green Weeding

    Science.gov (United States)

    Penniman, Sarah; McColl, Lisa

    2008-01-01

    Gone are the days of tiptoeing to the dumpsters with boxes of weeded books in tow. Lots of libraries are now taking advantage of the many low-cost services and solutions that promise to help extend the lives of collection discards. Some of these options can be very profitable. Some create goodwill within the local community. Some may seem more…

  4. The mitochondrial genome of the lone star tick (Amblyomma americanum).

    Science.gov (United States)

    Williams-Newkirk, Amanda J; Burroughs, Mark; Changayil, Shankar S; Dasch, Gregory A

    2015-09-01

    Amblyomma americanum is an abundant tick in the southeastern, midwestern, and northeastern United States. It is a vector of multiple diseases, but limited genomic resources are available for it. We sequenced the complete mitochondrial genome of a single female A. americanum collected in Georgia using the Illumina platform. The consensus sequence was 14,709 bp long, and the mean coverage across the assembly was >12,000×. All expected tick genomic features were present, including two "Tick-Box" motifs, and in the expected order for the Metastriata. Heteroplasmy rates were low compared to the most closely related tick for which data are available, Amblyomma cajennense. The phylogeny derived from the concatenated protein coding and rRNA genes from the 33 available tick mitochondrial genomes was consistent with those previously proposed for the Acari. This is the first complete mitochondrial sequence for A. americanum, which provides a useful reference for future studies of A. americanum population genetics and tick phylogeny.

  5. Transmission of Nepoviruses by Xiphinema americanum-group Nematodes.

    Science.gov (United States)

    Brown, D J; Halbrendt, J M; Robbins, R T; Vrain, T C

    1993-09-01

    The transmission of North American nepoviruses by putative species belonging to the Xiphinema americanum-group is reviewed. Xiphinema americanum sensu stricto, X. californicum, and X. rivesi each transmit cherry rasp leaf (CRLV), tobacco ringspot (TobRSV), and tomato ringspot nepovirus (TomRSV), and X. bricolensis is a vector of TomRSV. The apparent lack of specificity in the transmission of North American nepoviruses by X. americanum-group species markedly contrasts with the specific associations between European nepoviruses and their vector nematode species. Two complementary projects are described examining the taxonomic identity of putative species in the X. americanum-group, their morphological and genetic relationships, their ontogeny, and their ability to transmit viruses.

  6. Capacidade competitiva do jatobá com adubos verdes, forrageiras e plantas daninhas Competitive capacity of Hymenaea courbaril with green manure, forage species and weeds

    Directory of Open Access Journals (Sweden)

    A.M.M Gandini

    2011-01-01

    Full Text Available O estudo do consórcio entre espécies anuais e perenes representa uma ferramenta importante no processo de implantação e manejo florestal. O objetivo deste trabalho foi avaliar a capacidade competitiva do jatobá (Hymenaea courbaril com espécies de adubos verdes, forrageiras e plantas daninhas quanto à alocação de matéria seca, área foliar e concentração de nutrientes. Foram conduzidos dois experimentos, sendo os tratamentos compostos pela combinação de mudas de jatobá, desenvolvendo-se isoladamente ou em competição com cada uma das seguintes espécies: Brachiaria humidicola, Brachiaria brizantha, Brachiaria decumbens, Panicum maximum, Cajanus cajan, Canavalia ensiformis e Mucuna aterrima (experimento 1 e Bidens pilosa, Cenchrus echinatus, Euphorbia heterophylla, Lolium multiflorum e Solanum americanum (experimento 2, mais o cultivo de cada planta daninha e consorte isolada. Após convivência por 60 dias, as plantas foram coletadas para avaliação de matéria seca, área foliar e teor de nutrientes. Observou-se que a competição entre as plantas não promoveu alterações na produção de matéria seca ou área foliar do jatobá. Tendo em vista o exposto, verifica-se que a capacidade competitiva do jatobá não é afetada pela presença das espécies de adubos verdes e forrageiras, possibilitando convivência em fase inicial de desenvolvimento. Quanto à convivência das plantas daninhas com o jatobá, observou-se efeito positivo no acúmulo de nutrientes por estas.The study of intercropping between annual and perennial plants is an important tool in the process of forest implantation and management. The objective of this study was to assess the competitive capacity of jatoba (Hymeneae courbaril against green manure, forage and weed species, regarding the allocation of dry matter, leaf area and nutritional content. Two experiments were installed and the treatments consisted of combinations of jatoba seedlings per plot, alone

  7. Transmission of Hepatozoon americanum (Apicomplexa: Adeleorina) by ixodids (Acari: Ixodidae).

    Science.gov (United States)

    Ewing, S A; Mathew, J S; Panciera, R J

    2002-07-01

    American canine hepatozoonosis (ACH) caused by Hepatozoon americanum Vincent-Johnson, Macintire, Lindsay, Lenz, Baneth, and Shkap is an emerging, often fatal, tick-borne protozoal disease of dogs in the United States of America. Dogs acquire infection by ingesting ticks that contain oocysts. To understand the invertebrate (definitive) host range of H. americanum, experiments were carried out using four ixodids, Rhipicephalus sanguineus (Latreille), Dermacentor variabilis Say, Amblyomma americanum (L.), and Amblyomma maculatum Koch. Laboratory-reared nymphal ticks were fed on dogs that were either naturally or experimentally infected with H. americanum; when these ticks molted to the adult stage they were either fed to susceptible dogs or were dissected and examined for the presence of oocysts. Mature H. americanum oocysts were found in >90% of A. maculatum (both males and females), whereas oocysts were not found in any of the other three species. These results confirm that A. maculatum is an excellent host and vector for H. americanum and also suggest that this apicomplexan may have a narrow invertebrate host range, at least among ixodid ticks that are likely candidate vectors in the United States.

  8. Activity of mesotrione on resistant weeds in maize.

    Science.gov (United States)

    Sutton, Peter; Richards, Claire; Buren, Larry; Glasgow, Les

    2002-09-01

    Mesotrione is a new callistemone herbicide that inhibits the HPPD enzyme (p-hydroxyphenylpyruvate dioxygenase) and introduces a new naturally selective tool into weed-management programmes for use in maize. Mesotrione provides control of the major broad-leaved weeds, and it can be used in integrated weed-management programmes depending on the grower's preferred weed-control strategy. At post-emergence rates of 150 g AI ha-1 or less, mesotrione provides naturally selective control of key species that may show triazine resistance (TR), e.g. Chenopodium album L, Amaranthus species, Solanum nigrum L, as well as species of weed that show resistance to acetolactase synthase (ALS) inhibitors e.g. Xanthium strumarium L, Amaranthus spp and Sonchus spp. The data presented show that resistant and susceptible biotypes of these species with resistance to triazine herbicides, such as atrazine, simazine, terbutylazine and metribuzin, or ALS-inhibitor herbicides, such as imazethepyr, remain susceptible to mesotrione. These results confirm that there is no cross-resistance in biotypes with target site resistance to triazine or ALS-inhibiting herbicides. It is important that herbicide choice and rotation becomes an integral part of planning weed management, so as to minimise the risks of crop losses from weed competition, build-up of weed seed in the soil and the further development of weed resistance across a range of herbicide modes of action.

  9. Can Arbuscular Mycorrhizal Fungi Reduce the Growth of Agricultural Weeds?

    Science.gov (United States)

    Veiga, Rita S. L.; Jansa, Jan; Frossard, Emmanuel; van der Heijden, Marcel G. A.

    2011-01-01

    Background Arbuscular mycorrhizal fungi (AMF) are known for their beneficial effects on plants. However, there is increasing evidence that some ruderal plants, including several agricultural weeds, respond negatively to AMF colonization. Here, we investigated the effect of AMF on the growth of individual weed species and on weed-crop interactions. Methodology/Principal Findings First, under controlled glasshouse conditions, we screened growth responses of nine weed species and three crops to a widespread AMF, Glomus intraradices. None of the weeds screened showed a significant positive mycorrhizal growth response and four weed species were significantly reduced by the AMF (growth responses between −22 and −35%). In a subsequent experiment, we selected three of the negatively responding weed species – Echinochloa crus-galli, Setaria viridis and Solanum nigrum – and analyzed their responses to a combination of three AMF (Glomus intraradices, Glomus mosseae and Glomus claroideum). Finally, we tested whether the presence of a crop (maize) enhanced the suppressive effect of AMF on weeds. We found that the growth of the three selected weed species was also reduced by a combination of AMF and that the presence of maize amplified the negative effect of AMF on the growth of E. crus-galli. Conclusions/Significance Our results show that AMF can negatively influence the growth of some weed species indicating that AMF have the potential to act as determinants of weed community structure. Furthermore, mycorrhizal weed growth reductions can be amplified in the presence of a crop. Previous studies have shown that AMF provide a number of beneficial ecosystem services. Taken together with our current results, the maintenance and promotion of AMF activity may thereby contribute to sustainable management of agroecosystems. However, in order to further the practical and ecological relevance of our findings, additional experiments should be performed under field conditions. PMID

  10. Robotic weeding and automated weed measurements

    DEFF Research Database (Denmark)

    Christensen, S.; Søgaard, H.T.; Jørgensen, R.N.

    2003-01-01

    The goal of decreasing herbicide usage has so far focused on reducing the herbicide dosage or replacing chemical weed control by hoeing and harrowing. The conventional weed control strategy is to apply the same dose of herbicide or the same intensity of hoeing and harrowing in the whole field....... The strategy may be changed in the coming years because experiments in Germany, USA, Australia, and Denmark have shown that site-specific weed management can reduce herbicide usage significantly. One of the promising technologies for site specific weed management is robotic weeding. This paper reviews...... the state-of-the-art of automated weed measurement methods and the research projects concerning autonomous platform and information system for crop and weed monitoring and robotic weeding....

  11. Weed Identification Using An Automated Active Shape Matching (AASM) Technique

    DEFF Research Database (Denmark)

    Swain, K C; Nørremark, Michael; Jørgensen, R N

    2011-01-01

    Weed identification and control is a challenge for intercultural operations in agriculture. As an alternative to chemical pest control, a smart weed identification technique followed by mechanical weed control system could be developed. The proposed smart identification technique works...... on the concept of ‘active shape modelling’ to identify weed and crop plants based on their morphology. The automated active shape matching system (AASM) technique consisted of, i) a Pixelink camera ii) an LTI (Lehrstuhlfuer technische informatik) image processing library, iii) a laptop pc with the Linux OS. A 2......-leaf growth stage model for Solanum nigrum L. (nightshade) is generated from 32 segmented training images in Matlab software environment. Using the AASM algorithm, the leaf model was aligned and placed at the centre of the target plant and a model deformation process carried out. The parameters used...

  12. Amblyomma americanum: a potential vector of human ehrlichiosis.

    Science.gov (United States)

    Anderson, B E; Sims, K G; Olson, J G; Childs, J E; Piesman, J F; Happ, C M; Maupin, G O; Johnson, B J

    1993-08-01

    Polymerase chain reaction primers specific for Ehrlichia chaffeensis were used to amplify DNA from extracts of pooled ticks. Amplification was performed on extracts from 140 pools (1,579 total ticks) consisting of three tick genera collected from five states. The characteristic 389-basepair product was observed after amplification of extracts from seven different pools of adult Amblyomma americanum (117 pools, 1,462 ticks), but not from pools of nymphs. No specific product was observed after amplification of 20 pools (105 ticks) of Dermacentor variabilis and three pools of Ixodes scapularis (12 ticks). Ehrlichia chaffeensis was present in A. americanum at a minimum frequency of > or = 0.48%, suggesting that A. americanum may be a vector of human ehrlichiosis.

  13. Ecologically sustainable weed management

    DEFF Research Database (Denmark)

    Liebman, Matt; Baraibar, Bàrbara; Buckley, Yvonne

    2016-01-01

    will be effective in various locations. Implementing new approaches for weed management will require multidisciplinary teams comprised of scientists, engineers, economists, sociologists, educators, farmers, land managers, industry personnel, policy makers, and others willing to focus on weeds within whole farming......Weed management is a critically important activity on both agricultural and non-agricultural lands, but it is faced with a daunting set of challenges: environmental damage caused by control practices, weed resistance to herbicides, accelerated rates of weed dispersal through global trade......, and greater weed impacts due to changes in climate and land use. Broad-scale use of new approaches is needed if weed management is to be successful in the coming era. We examine three approaches likely to prove useful for addressing current and future challenges from weeds: diversifying weed management...

  14. Inbreeding depression in Solanum carolinense (Solanaceae), a species with a plastic self-incompatibility response

    NARCIS (Netherlands)

    Mena-Ali, J.I.; Keser, L.H.; Stephenson, A.G.

    2008-01-01

    Solanum carolinense (horsenettle) is a highly successful weed with a gametophytic self-incompatibility (SI) system. Previous studies reveal that the strength of SI in S. carolinense is a plastic trait, associated with particular S-alleles. The importance of this variation in self-fertility on the

  15. Variation in seed traits and germination potential of Solanum elaeagnifolium Cav. Following its invasion in Greece

    Science.gov (United States)

    Solanum elaeagnifolium Cav. (Silverleaf nightshade) is presently considered to be one of the worst agricultural weeds around the world including the Mediterranean basin. Plant’s native range is considered to be an area expanding from Southern US to Northern Mexico. Introduced unintentionally from so...

  16. Vector Capability of Xiphinema americanum sensu lato in California.

    Science.gov (United States)

    Griesbach, J A; Maggenti, A R

    1989-10-01

    Seven field populations of Xiphinema americanum sensu lato from California's major agronomic areas were tested for their ability to transmit two nepoviruses, including the prune brownline, peach yellow bud, and grapevine yellow vein strains of tomato ringspot virus and the bud blight strain of tobacco ringspot virus. Two field populations transmitted all isolates, one population transmitted all tomato ringspot virus isolates but failed to transmit bud blight strain of tobacco ringspot virus, and the remaining four populations failed to transmit any virus. Only one population, which transmitted all isolates, bad been associated with field spread of a nepovirus. As two California populations of Xiphinema americanum sensu lato were shown to have the ability to vector two different nepoviruses, a nematode taxonomy based on a parsimony of virus-vector relationship is not practical for these populations. Because two California populations of X. americanum were able to vector tobacco ringspot virus, commonly vectored by X. americanum in the eastern United States, these western populations cannot be differentiated from eastern populations by vector capability tests using tobacco ringspot virus.

  17. Marijuana (Weed, Pot) Facts

    Science.gov (United States)

    ... That People Abuse » Marijuana (Weed, Pot) Facts Marijuana (Weed, Pot) Facts Listen Marijuana is a green, brown, or gray mix of dried, shredded leaves and flowers from the marijuana plant. Marijuana can be rolled up and smoked ...

  18. Eradication of Major Weeds

    Science.gov (United States)

    Indian Journal of Adult Education, 1975

    1975-01-01

    Strategies for weed control in cropped and non-cropped areas are presented together with an operational plan for implementing a program for weed control at the national level. The program includes training personnel and community education procedures. (EC)

  19. Eradication of Major Weeds

    Science.gov (United States)

    Indian Journal of Adult Education, 1975

    1975-01-01

    Strategies for weed control in cropped and non-cropped areas are presented together with an operational plan for implementing a program for weed control at the national level. The program includes training personnel and community education procedures. (EC)

  20. Ecologically sustainable weed management

    NARCIS (Netherlands)

    Liebman, Matt; Baraibar, Bàrbara; Buckley, Yvonne; Childs, Dylan; Christensen, Svend; Cousens, Roger; Eizenberg, Hanan; Heijting, Sanne; Loddo, Donato; Merotto, Aldo; Renton, Michael; Riemens, Marleen

    2016-01-01

    Weed management is a critically important activity on both agricultural and non-agricultural lands, but it is faced with a daunting set of challenges: environmental damage caused by control practices, weed resistance to herbicides, accelerated rates of weed dispersal through global trade, and

  1. Crop–weed competition

    DEFF Research Database (Denmark)

    Gallandt, Eric R.; Weiner, Jacob

    2015-01-01

    on crops. Longer term management of crop–weed competition can be achieved through crop rotations, specifically crop sequences that reduce the weed seed bank, and therefore seedling density, and prevent proliferation of perennial weeds. Key ConceptsKey Concepts * Plant growth requires sunlight, water...

  2. Horny Goat Weed

    Science.gov (United States)

    Horny goat weed is an herb. The leaves are used to make medicine. As many as 15 horny goat weed species are known as “yin yang huo” in Chinese medicine. Horny goat weed is used for weak back and knees, joint ...

  3. Atividade potencialmente alelopática do óleo essencial de Ocimum americanum Potentially allelophatic activity of the essential oil of Ocimum americanum

    Directory of Open Access Journals (Sweden)

    A.P.S. Souza Filho

    2009-01-01

    Full Text Available Os óleos essenciais são reconhecidos pelas suas diversificadas ações biológicas. A biodiversidade amazônica é rica em espécies de plantas produtoras de óleos essenciais. Neste trabalho, objetivou-se caracterizar a atividade potencialmente alelopática do óleo essencial de Ocimum americanum (estoraque e determinar seus efeitos sobre a germinação de sementes e o desenvolvimento de duas espécies de plantas daninhas. O óleo essencial foi testado em concentrações variando de 100 a 2.000 mg L-1, considerando seus efeitos sobre a germinação de sementes (25 ºC de temperatura constante e fotoperíodo de 12 horas e o desenvolvimento da radícula e do hipocótilo (25 ºC de temperatura constante e fotoperíodo de 24 horas das plantas daninhas malícia (Mimosa pudica e mata-pasto (Senna obtusifolia. Fatores relacionados a concentração, especificidade das plantas receptoras e parâmetros analisados foram decisivos para os efeitos obtidos. A tendência geral foi de relação positiva entre concentração e efeito inibitório. Malícia foi mais sensível aos efeitos do que mata-pasto. Comparativamente, a germinação, seguida do desenvolvimento da radícula, foi afetada pelo óleo essencial em maior magnitude, ficando o desenvolvimento do hipocótilo como o de menor sensibilidade. Os efeitos observados podem ser atribuídos à presença, no óleo essencial, de monoterpenos, monoterpenos oxigenados, sesquiterpenos, alifáticos e fenilpropanoides, com destaque para os constituintes com atividade alelopática já comprovada, como o limoneno, a cânfora e o linalol.Essential oils are known for their several biological activities. The biodiversity of the Amazon region is rich in essential-oil producing plants.The aim of this work was to study the potentially allelopathic activity of the essential oil of Ocimum americanum and to determine its effects on seed germination and growth of two weed species. Solutions of the essential oil were tested

  4. Distribution of Xiphinema americanum and Related Species in North America.

    Science.gov (United States)

    Robbins, R T

    1993-09-01

    All species of the Xiphinema americanum-group and their synonyms are listed. The North American species reported are listed by state or province. Among these species, X. rivesi has the most widely reported distribution. Six species (X. diffusum, X. floridae, X. laevistriatum, X. luci, X. shell, and X. tarjanense) have been reported from only Florida. The reports of X. pachtaicum, X. sheri, and X. luci did not include morphometrics and need to be confirmed; X. brevicolle from California was identified before Lamberti and Bleve-Zacheo described 15 new species in 1979 and similarly needs to be confirmed. Because of the proliferation of species in this group, reports of X. americanum (sensu stricto) before 1979 are questionable. Extraction techniques for longidorids are discussed.

  5. Serological Strains of Tobacco Ringspot Virus Transmitted by Xiphinema americanum.

    Science.gov (United States)

    Rush, M C

    1970-07-01

    Five serological strains of tobacco ringspot virus isolated from naturally infected tobacco in North Carolina, and a strain isolated from watermelon in the Rio Grande Valley of Texas were transmitted from cucumber to cucumber by mass-screened and handpicked Xiphinerna americanum from North Carolina. The Eucharis mottle strain from Peru was not transmitted, indicating that a specific strain-vector relationship may exist between the geographically isolated strains from North and South America.

  6. Introduction to Weeds and Herbicides.

    Science.gov (United States)

    Hartwig, Nathan L.

    This agriculture extension service publication from Pennsylvania State University is an introduction to weed control and herbicide use. An initial discussion of the characteristics of weeds includes scientific naming, weed competition with crops, weed dispersal and dormancy, and conditions affecting weed seed germination. The main body of the…

  7. Introduction to Weeds and Herbicides.

    Science.gov (United States)

    Hartwig, Nathan L.

    This agriculture extension service publication from Pennsylvania State University is an introduction to weed control and herbicide use. An initial discussion of the characteristics of weeds includes scientific naming, weed competition with crops, weed dispersal and dormancy, and conditions affecting weed seed germination. The main body of the…

  8. Disease agents in Amblyomma americanum from northeastern Georgia.

    Science.gov (United States)

    Varela, A S; Moore, V A; Little, S E

    2004-07-01

    Amblyomma americanum (lone star tick) is known or suspected to vector several organisms that are implicated as human pathogens, including Ehrlichia chaffeensis, E. ewingii, and Borrelia lonestari. These three agents have also been detected in white-tailed deer (Odocoileus virginianus). Because northeastern Georgia has a high abundance of both lone star ticks and white-tailed deer, and one of these organisms, E. chaffeensis, is already known to be endemic in the area, we assayed individual adult A. americanum, collected during the spring of 2001, 2002, and 2003, for these three organisms. A total of 400 ticks were dissected and tissues assayed by polymerase chain reaction (PCR) using Ehrlichia species-specific and Borrelia genus-wide primers. Of ticks tested, 2.0% (8/398) had evidence of E. chaffeensis, 4.8% (19/398) had evidence of E. ewingii, and 1.0% (4/398) had evidence of B. lonestari. Borrelia sp. spirochetes were also visualized by an indirect fluorescent antibody test, using an anti-flagellin monoclonal antibody (H9724), in a total of 10.7% (32/300) of ticks tested in 2003. These results reconfirm the presence of E. chaffeensis and establish evidence of E. ewingii and B. lonestari in questing adult A. americanum ticks from northeastern Georgia. Detection of at least two of the three organisms in ticks collected each year suggests that people in northeastern Georgia are at risk of infection with these organisms.

  9. Xiphinema americanum as Affected by Soil Organic Matter and Porosity.

    Science.gov (United States)

    Ponchillia, P E

    1972-07-01

    The effects of four soil types, soil porosity, particle size, and organic matter were tested on survival and migration of Xiphinema americanum. Survival and migration were significantly greater in silt loam than in clay loam and silty clay soils. Nematode numbers were significantly greater in softs planted with soybeans than in fallow softs. Nematode survival was greatest at the higher of two pore space levels in four softs. Migration of X. americanum through soft particle size fractions of 75-150, 150-250, 250-500, 500-700, and 700-1,000 mu was significantly greater in the middle three fractions, with the least occurring in the smallest fraction. Additions of muck to silt loam and loamy sand soils resulted in reductions in survival and migration of the nematode. The fulvic acid fraction of muck, extracted with sodium hydroxide, had a deleterious effect on nematode activity. I conclude that soils with small amounts of air-filled pore space, extremes in pore size, or high organic matter content are deleterious to the migration and survival of X. americanum, and that a naturally occurring toxin affecting this species may be present in native soft organic matter.

  10. Ribosomal and Mitochondrial DNA Analyses of Xiphinema americanum-Group Populations.

    Science.gov (United States)

    Lazarova, Stela S; Malloch, Gaynor; Oliveira, Claudio M G; Hübschen, Judith; Neilson, Roy

    2006-12-01

    The 18S ribosomal DNA (rDNA) and cytochrome oxidase I region of mitochondrial DNA (mtDNA) were sequenced for 24 Xiphinema americanum-group populations sourced from a number of geographically disparate locations. Sequences were subjected to phylogenetic analysis and compared. 18S rDNA strongly suggested that only X. pachtaicum, X. simile (two populations) and a X. americanum s.l. population from Portugal were different from the other 20 populations studied, whereas mtDNA indicated some heterogeneity between populations. Phylogenetically, based on mtDNA, an apparent dichotomy existed amongst X. americanum-group populations from North America and those from Asia, South America and Oceania. Analyses of 18S rDNA and mtDNA sequences underpin the classical taxonomic issues of the X. americanum-group and cast doubt on the degree of speciation within the X. americanum-group.

  11. Site Specific Weed Control Technologies

    DEFF Research Database (Denmark)

    Christensen, Svend; Søgaard, Henning Tangen; Kudsk, Per;

    2009-01-01

    describe the basic parts of site specific weed control technologies, comprising of weed sensing systems, weed management models and precision weed control implements. A review of state-of-the-art technologies shows that several weed sensing systems and precision implements have been developed over the last...... of knowledge about the economic and environmental potential for increasing the resolution of weed control. The integration of site-specific information on weed distribution, weed species composition and density, and the effect on crop yield, is decisive for successful site-specific weed management.   Keywords......Site-specific weed control technologies are defined as machinery or equipment embedded with technologies that detect weeds growing in a crop and, taking into account predefined factors such as economics, takes action to maximise the chances of successfully controlling them. In the article, we...

  12. Weeding Library Collections.

    Science.gov (United States)

    Slote, Stanley J.

    This work, based on two recent research projects in the weeding of library collections and the identification of core collections, provides a comprehensive summary of the literature and research on these topics. It also presents practical guidance in weeding for the professional librarian or for the library school student. The book is divided into…

  13. RoboWeedSupport

    DEFF Research Database (Denmark)

    Dyrmann, Mads; Nyholm Jørgensen, Rasmus

    2015-01-01

    Information about the weed population in fields is important for determining the optimal herbicides for the fields. A system based on images is presented that can provide support in determining the species and density of the weeds. Firstly, plants are segmented from the soil. Plants that after th...

  14. Solanum lycopersicum (Tomato)

    NARCIS (Netherlands)

    Pavan, S.N.C.; Heusden, van A.W.; Bai, Y.

    2009-01-01

    After its introduction in Europe the tomato (Solanum lycopersicum) has gone a long way. Dedicated breeding has resulted in numerous cultivars grown all over the world, differing in all kind of aspects such as yield, shape, resistance, taste and quality. Modern cultivars are sold as hybrids with a

  15. Solanum lycopersicum (Tomato)

    NARCIS (Netherlands)

    Pavan, S.N.C.; Heusden, van A.W.; Bai, Y.

    2009-01-01

    After its introduction in Europe the tomato (Solanum lycopersicum) has gone a long way. Dedicated breeding has resulted in numerous cultivars grown all over the world, differing in all kind of aspects such as yield, shape, resistance, taste and quality. Modern cultivars are sold as hybrids with a ve

  16. Assessment of Corn Densities on Ecological Indices of Weed Species

    Directory of Open Access Journals (Sweden)

    G Mahmoodi

    2012-06-01

    Full Text Available Diversity, dominance, and stability of weeds are the most important ecological properties in agricultural systems, which influenced by management factors such as crop density, abundantly. This experiment was conducted in 2009 at Ferdowsi University of Mashhad Research Field. The experimental design was interval mapping with four levels of corn densities (5, 6, 7 and 9 plant.m-2 and four levels of weed control (full-control, without control, broad-leaves control and grasses control. Weed sampling was done at 3 stages included beginning and end of critical period weed control and harvesting time. The results showed that the effect of plant density on species diversity was significant; some how the amount of Shanon and Simpson Indices were lowest in the 9 plant.m-2 (0.39 and 0.45, respectively and greatest in 5 plant.m-2 (0.84. The results also showed that the maximum amount of dominance index was observed in 9 plant.m-2, that was seen in Echinochloa crus- galli and Convulvulus arvensis at the beginning of growing season, then in Solanum nigrum and Amaranthus retroflexus in the end of growing season. The amount of community dominance index in 9 plant.m-2 was higher than other densities, and it decreased with decline of densities. based on the results of present experiment the linear relationship between plant species and area was found. The calculated amount of Alpha and Beta diversities. in a θ and β scales based on coefficients of this relationship were 0.534 (four species per unit area and 0.29 (two species per unit area, respectively. In conclusion the result of this experiment pointed that the weeds diversity decreased with increasing of corn density, weed diversity decreased and therefore, having appropriate plant density is very efficient for sustainable weed management.

  17. The role of weeds in the spread of Tomato spotted wilt virus by thrips tabaci (Thysanoptera: Thripidae) in tobacco crops

    NARCIS (Netherlands)

    Chatzivassiliou, E.K.; Peters, D.; Katis, N.I.

    2007-01-01

    Oviposition of Thrips tabaci, larval development and their potential to acquire Tomato spotted wilt virus (TSWV) from infected Amaranthus retroflexus, Datura stramonium, Lactuca serriola, Solanum nigrum and Sonchus oleraceus plants and the ability of the adults to transmit this virus to these weeds

  18. Potato (Solanum tuberosum L.).

    Science.gov (United States)

    Chetty, Venkateswari J; Narváez-Vásquez, Javier; Orozco-Cárdenas, Martha L

    2015-01-01

    Agrobacterium-mediated transformation is the most common method for the incorporation of foreign genes into the genome of potato as well as many other species in the Solanaceae family. This chapter describes protocols for the genetic transformation of three species of potato: Solanum tuberosum subsp. tuberosum (Desiréé), S. tuberosum subsp. andigenum (Blue potato), and S. tuberosum subsp. andigena using internodal segments as explants.

  19. The Politics of Weeding.

    Science.gov (United States)

    Tillman, Hope N.

    1988-01-01

    Reviews the literature that deals with the political ramifications of weeding material from academic library collections and the need to involve users and other libraries within the institution in the decision process. (14 references) (CLB)

  20. Robotic weed monitoring

    DEFF Research Database (Denmark)

    Bochtis, Dionysis; Sørensen, Claus Aage Grøn; Jørgensen, R N

    2011-01-01

    -farm operating console, the mobile robotic unit, and a field server for generating and storingmaps. The hypothesis is that it is possible to automate the planning and execution of theoperation of monitoring of the in-field weed density and species distribution. The developedplanning system includes the automatic...... of the weed monitoring operation.Key words: autonomous vehicles, farm management, mission planning, route planning,sampling....

  1. Redescription of Xiphinema americanum Cobb, 1913 with Comments on Its Morphometric Variations.

    Science.gov (United States)

    Lamberti, F; Golden, A M

    1984-04-01

    Xiphinema americanum is redescribed and illustrated from material collected from Arlington Cemetery, near Cobb's type locality (Falls Church, Virginia), Morphometric data showing variations within this species are given for three additional populations.

  2. Weed seed bank response to 12 years of different fertilization systems.

    Science.gov (United States)

    De Cauwer, B; Van den Berge, K; Cougnon, M; Bulcke, R; Reheul, D

    2010-01-01

    Fertilizer amendments can impact weed populations in a variety of ways. This study evaluated the effects of 12 year-long applications of different fertilization systems on size and composition of the weed seed bank in a conventionally managed maize monoculture field. Fertilization systems included all factorial combinations of two dairy cattle slurry rates, three vegetable, fruit and garden waste (VFG) compost rates, and three synthetic N fertilizer rates. Soil samples were taken in each subplot in May 2008 after sowing and prior to herbicide application. Residues recovered from soil samples were tested for weed seedling emergence to characterize soil seed banks. Total weed seed bank density was affected by mineral N fertilization but not by compost or animal slurry application. Weed seed bank composition was related to compost amendment and mineral N fertilization. Annual compost amendments reduced seed bank density of some persistent species (e.g., Chenopodium album and Solanum nigrum) irrespective of mineral N fertilization. Compost is a promising tool for incorporation into integrated weed control strategies aimed at reducing weed seed bank persistence.

  3. Discovery of filarial nematode DNA in Amblyomma americanum in Northern Virginia

    OpenAIRE

    Henning, Tyler C.; Orr, John M.; Smith, Joshua D.; Arias, Jorge R.; Rasgon, Jason L.; Norris, Douglas E.

    2015-01-01

    Ticks collected in 2011 were screened for the presence of filarial nematode genetic material, and positive samples were sequenced for analysis. Monanema-like filarial nematode DNA was recently discovered in Amblyomma americanum in northern Virginia, marking the first time genetic material from this parasite has been discovered in ticks in the state. Phylogenetic analysis revealed that this material was directly related to a previously discovered filarial nematode in A. americanum populations ...

  4. Seasonal Population Fluctuation of Xiphinema americanum and X. rivesi in New York and Pennsylvania Orchards.

    Science.gov (United States)

    Jaffee, B A; Harrison, M B; Shaffer, R L; Strang, M B

    1987-07-01

    The population fluctuation and composition of Xiphinema americanum (sensu stricto) and X. rivesi were studied in a New York apple orchard (only X. americanum present), a Pennsylvania apple orchard (both X. americanum and X. rivesi present), and a Pennsylvania peach orchard (X. americanum, X. rivesi, and X. californicum present). Few clear trends in population fluctuation or composition were observed. The adult female was the predominant stage in most sample periods, and the reproductive period was limited to late spring and early summer. Only a few of the females at any sample period were gravid. All stages were present throughout the year, and all stages overwintered. Eggs in soil were not monitored. In the Pennsylvania apple orchard, X. americanum and X. rivesi were easily separated by morphological characteristics; however, the two species did not display differences in population structure or composition. The predominance of adults, the relatively low reproductive rates, and the association of these species with stable habitats suggest that the life strategies of X. americanum and X. rivesi are K-selected as opposed to r-selected.

  5. Effect of winter maize-based intercropping systems on maize yield, associated weeds and economic efficiency

    OpenAIRE

    2014-01-01

    A field experiment was conducted during winter seasons of 2003-04 and 2004-05 at Kanpur, India to study the effect of winter maize (Zea mays L.) based intercropping systems on maize yield, associated weeds and economics under irrigated condition of central Uttar Pradesh. Thirteen maize-based cropping systems such as maize sole, potato (Solanum tuberosum L.) sole, mustard [Brassica juncea (L.) Czernj. & Cosson] sole, toria (Brassica campestris var. toria) sole, pea (Pisum sativum L.) sole, lin...

  6. Weeds and Wildlife: Perceptions and Practices of Weed Managers

    Directory of Open Access Journals (Sweden)

    Emma H Carlos

    2014-01-01

    Full Text Available Negative impacts of invasive plants or weeds on biodiversity have been well established yet their role in providing key habitats and resources for wildlife has been little understood. Weed removal thus has the potential to adversely affect wildlife but whether this is considered during weed management is poorly known. To determine the extent of this knowledge, we examined the perceptions of weed managers regarding wildlife and weed management in Victoria, Australia. We surveyed 81 weed managers of varying levels of experience from different types of organisations, including state and local government, community groups and private companies. We found 90% of managers had observed wildlife-weed interactions and that most (70% adjusted management programmes to accommodate wildlife. Despite this, few (19% had adopted the recommended practice of combining gradual weed removal with re-vegetation. While management programmes included monitoring of native vegetation, consideration of wildlife monitoring in weed management was rare. This highlights the need for management to better understand and respond to wildlife-weed relationships. If the improvement of wildlife habitat is included in the objectives of weed programmes, as it should be, then wildlife should also be incorporated in project monitoring. This would lead to a greater understanding of the role weeds and their management have in each situation and, ultimately, more informed decision making.

  7. Transdisciplinary weed research: new leverage on challenging weed problems?

    NARCIS (Netherlands)

    Jordan, N.; Schut, M.; Graham, S.; Barney, J.N.; Childs, D.Z.; Christensen, S.B.; Cousens, R.D.; Davis, A.S.; Eizenberg, H.; Ervin, D.E.; Fernandez-Quintanilla, C.; Harrison, L.J.; Harsch, M.A.; Heijting, S.; Liebman, M.; Loddo, D.; Mirsky, S.B.; Riemens, M.; Neve, P.; Peltzer, D.A.; Renton, M.; Williams, M.; Recasens, J.; Sønderskov, M.

    2016-01-01

    Transdisciplinary weed research (TWR) is a promising path to more effective management of challenging weed problems. We define TWR as an integrated process of inquiry and action that addresses complex weed problems in the context of broader efforts to improve economic, environmental and social

  8. Transdisciplinary weed research: new leverage on challenging weed problems?

    Science.gov (United States)

    Transdisciplinary Weed Research (TWR) is a promising path to more effective management of challenging weed problems. We define TWR as an integrated process of inquiry and action that addresses complex weed problems in the context of broader efforts to improve economic, environmental and social aspec...

  9. Grass and weed killer poisoning

    Science.gov (United States)

    ... medlineplus.gov/ency/article/002838.htm Grass and weed killer poisoning To use the sharing features on this page, please enable JavaScript. Many weed killers contain dangerous chemicals that are harmful if ...

  10. Intercropping leeks to suppress weeds

    NARCIS (Netherlands)

    Baumann, D.T.; Kropff, M.J.; Bastiaans, L.

    2000-01-01

    Many field vegetables such as leek are weak competitors against weeds, causing high costs for weed management practice. Using celery as a companion cash crop was suggested to improve the weed suppression of leek. Three field experiments were carried out to study the intra- and interspecific competit

  11. Evidence of Borrelia lonestari DNA in Amblyomma americanum (Acari: Ixodidae) removed from humans.

    Science.gov (United States)

    Stromdahl, Ellen Y; Williamson, Phillip C; Kollars, Thomas M; Evans, Sandra R; Barry, Ryan K; Vince, Mary A; Dobbs, Nicole A

    2003-12-01

    We used a nested PCR with Borrelia flagellin gene (flaB) primers and DNA sequencing to determine if Borrelia lonestari was present in Amblyomma americanum ticks removed from military personnel and sent to the Tick-Borne Disease Laboratory of the U.S. Army Center for Health Promotion and Preventive Medicine. In our preliminary investigation, we detected Borrelia sequences in 19 of 510 A. americanum adults and nymphs from Ft. A. P. Hill, Va. During the 2001 tick season, the flaB primers were used to test all A. americanum samples as they were received, and 29 of 2,358 A. americanum samples tested individually or in small pools were positive. PCRs with 2,146 A. americanum samples in 2002 yielded 26 more Borrelia-positive samples. The positive ticks in 2001 and 2002 were from Arkansas, Delaware, Kansas, Kentucky, Maryland, New Jersey, North Carolina, Tennessee, and Virginia. The last positive sample of the 2001 season was a pool of larvae. To further investigate larval infection, we collected and tested questing A. americanum larvae from Aberdeen Proving Ground, Md.; 4 of 33 pools (40 larvae per pool) were positive. Infection of unfed larvae provides evidence of the maintenance of B. lonestari by means of transovarial transmission. Sequence analysis revealed that the amplicons were identical to sequences of the B. lonestari flaB gene in GenBank. Despite the low prevalence of infection, the risk of B. lonestari transmission may be magnified because A. americanum is often abundant and aggressive, and many tick bite victims receive multiple bites.

  12. Role of Weed Emergence Time for the Relative Seed Production in Maize

    Directory of Open Access Journals (Sweden)

    Stefano Benvenuti

    2007-03-01

    Full Text Available Trials were carried out in 2000 and 2001 to investigate the effect of weed emergence time on weed seed production in a maize field. Datura stramonium L., Solanum nigrum L. and Abutilon theophrasti Medicus were selected for their importance as summer weeds. Emergence time was found to be crucial since delay would involve an unfavourable light environment determined by crop canopy elongation and resulting shade production. Only the early emergence of D. stramonium and A. theophrasti showed the capacity to exposing their leaves over the crop canopy. Generally the weed seed production under shade conditions decreased for the reduction of the fruit per plant since the number of seed per plant showed only a light reduction. However, while D. stramonium and A. theophrasti compete with the crop by increasing height, Solanum nigrum tends to adjust to shade without excessive reduction in number of seeds produced. Thus in D. stramonium and A. theophrasti late emergence reduced seed production to only 15%, while S. nigrum maintained 25% of the seed production level generally observed with greater light exposure. This environmental adaptation was confirmed by the less marked decrease in S. nigrum harvest index. Agroecological involvements are discussed.

  13. Determination of fungal pathogens of common weed species in the vicinity of Tokat, Turkey.

    Science.gov (United States)

    Kadioğlu, I; Karamanli, N; Yanar, Y

    2010-01-01

    This study was carried out to determine the fungal pathogens on Chenopodium album L., Cirsium arvense (L.) Scop., Convolvulus arvensis L., Cynodon dactylon (L.) Pers., Delphinium consolida L., Portulaca oleracea L., Rumex crispus L., Solanum nigrum L., Sorghum halepense (L.) Pers. and Xanthium strumarium L. which were common weed species of agricultural areas. Surveys were conducted in May-June and August-September in 2004-2005 growing seasons. During the surveys density and frequency of the above mentioned weed species were also determined and number of infected plants was counted in each sampling area. Infected weed samples were collected from each sampling point and brought to the laboratory in polyethylene bags and the pathogens were identified at genus or species level. As a result of two year surveys, ten fungal pathogens were determined on eight weed species. The most important fungal pathogens determined on common weed species were as follow; Peronospora farinosa (Fr.) Fr. on C. album, and Septoria convolvuli DC., Erysiphe convolvuli DC., and Puccinia punctiformis (Strauss) Roehrl. on C. arvensis. These fungal diseases were observed mainly on the weeds located at the borders of fields. Infection rates of these pathogens reached up to 21.2% in some of the survey areas. Further studies should be conducted to evaluate the efficacy of these pathogen under in vitro and in vivo conditions.

  14. What Price Weeding?

    Science.gov (United States)

    Ettelt, Harold J.

    1985-01-01

    Describes a study conducted at Columbia-Greene Community College's library to determine whether a book's previous non-use is indicative of future non-use; whether books are progressively less likely to be used with time; the circulation costs of weeding previously unused books; and the circulation rates of old and new books. (DMM)

  15. Controlling Landscape Weeds.

    Science.gov (United States)

    Nuss, James Robert, Jr.

    This agriculture extension service publication from Pennsylvania State University discusses the control of common grass and broadleaf weeds through the use of mulches and herbicides. The section on mulches discusses the different types of mulching materials, their advantages and disadvantages, herbicide-mulch combinations, and lists source of…

  16. Biotechnology in weed control

    Science.gov (United States)

    Biotechnology can be used to enhance the management of weeds in several ways. Crops have been made resistant to herbicides by inserting transgenes that impart herbicide resistance into the plant genome. Glyphosate and glufosinate-resistant crops are commercialized in North America and crops made res...

  17. Weed Research in Mint

    Science.gov (United States)

    Weeds present in peppermint and spearmint reduce mint oil yield and quality. Flumioxazin combinations with clomazone and pendimethalin applied to dormant peppermint controlled prickly lettuce and flixweed without significant injury to the crop. Low rates of flumioxazin and sulfentrazone applied imm...

  18. Controlling Landscape Weeds.

    Science.gov (United States)

    Nuss, James Robert, Jr.

    This agriculture extension service publication from Pennsylvania State University discusses the control of common grass and broadleaf weeds through the use of mulches and herbicides. The section on mulches discusses the different types of mulching materials, their advantages and disadvantages, herbicide-mulch combinations, and lists source of…

  19. Soil Property Influences on Xiphinema americanum Populations as Related to Maturity of Loess-Derived Soils.

    Science.gov (United States)

    Schmitt, D P

    1973-10-01

    Field populations of Xiphinerna americanum around roots of Syringa vulgaris 'President Lincoln' were larger in Marshall silty clay loam, a medially developed loess soil, than in Monona silt loam, a minimally developed loess soil. Most X. amerieanum occurred in the top 15 cm of soil, with few below 30 cm. Maximum numbers occurred in August of both years in the Marshall soil, and in August 1969 and June 1970 in the Monona soil. Population fluctuations during the growing season were coincident with changes in soil moisture content. Although the population fluctuation pattern was the same at each depth tested, the adult-to-juvenile ratio increased in one soil while it decreased in the other. Numbers of X. americanum decreased as root weights decreased within a soil profile, but they were not correlated with root weights over all soils and depths. More X. americanum were recovered from the Marshall than from the Monona soil, but fibrous root weights were greater in the Monona soil. Survival of X. americanum in soil columns in growth chamber experiments was better in the Marshall than in the Monona soil. Movement and survival were different in identically textured Monona A and B horizon soils. Factors related to the ion exchange sites may affect X. americanum.

  20. Using mitogenomic and nuclear ribosomal sequence data to investigate the phylogeny of the Xiphinema americanum species complex

    Science.gov (United States)

    Nematodes within the Xiphinema americanum species complex are economically important because they vector nepoviruses which cause considerable damage to a variety of agricultural crops. The taxonomy of X. americanum is controversial, with the number of putative species being the subject of debate. Ac...

  1. Inbreeding in horsenettle (Solanum carolinense) alters night-time volatile emissions that guide oviposition by Manduca sexta moths

    OpenAIRE

    Kariyat, Rupesh R.; Kerry E. Mauck; Balogh, Christopher M.; Andrew G. Stephenson; Mescher, Mark C.; De Moraes, Consuelo M.

    2013-01-01

    Plant volatiles serve as key foraging and oviposition cues for insect herbivores as well as their natural enemies, but little is known about how genetic variation within plant populations influences volatile-mediated interactions among plants and insects. Here, we explore how inbred and outbred plants from three maternal families of the native weed horsenettle (Solanum carolinense) vary in the emission of volatile organic compounds during the dark phase of the photoperiod, and the effects of ...

  2. Weed Identification and Control in Vegetable Crops.

    Science.gov (United States)

    Ferretti, Peter A., Comp.

    This agriculture extension service publication from Pennsylvania State University examines weed control and identification in vegetable crops. Contents include: (1) Types of weeds; (2) Reducing losses caused by weeds, general control methods and home garden weed control; (3) How herbicides are used; (4) Specific weeds in vegetable plantings; and…

  3. Weed Identification and Control in Vegetable Crops.

    Science.gov (United States)

    Ferretti, Peter A., Comp.

    This agriculture extension service publication from Pennsylvania State University examines weed control and identification in vegetable crops. Contents include: (1) Types of weeds; (2) Reducing losses caused by weeds, general control methods and home garden weed control; (3) How herbicides are used; (4) Specific weeds in vegetable plantings; and…

  4. Effect of deer exclusion by fencing on abundance of Amblyomma americanum (Acari: Ixodidae) on Fire Island, New York, USA.

    Science.gov (United States)

    Ginsberg, Howard S; Butler, Mari; Zhioua, Elyes

    2002-12-01

    The effects of deer exclusion on northern populations of lone star ticks, Amblyomma americanum, were tested at the Lighthouse Tract, Fire Island, NY, USA, where densities of this species have increased recently. Game fencing was erected to exclude deer from two sites of roughly one ha each, and populations of nymphal and adult A. americanum within were compared with those at control sites outside the exclosures. Percent control of nymphs within vs. outside the exclosures averaged 48.4% in the four years post-treatment, compared to pretreatment values. Percent control varied markedly in different years, suggesting that factors in addition to deer densities had strong effects on population densities of A. americanum. Exclosures of this size did not control adult A. americanum. Effects of deer exclusion in this recently expanded northern population of A. americanum were similar to those that have been reported for southern populations of this species.

  5. Identification of weed species with hyperaccumulative characteristics of heavy metals

    Institute of Scientific and Technical Information of China (English)

    WEI Shuhe; ZHOU Qixing

    2004-01-01

    In order to promote the effective and economic remediation of soils contaminated with single Cd and Cd combined with Ph, Cu and Zn, a field-screening study on weed hyperaccumulators was carried out on the basis of field pot-culture experiments used to determine characteristics of weed plants enduring and accumulating heavy metals. In this study, 54 weed species belonging to 20 families from agricultural fields of the Shengyang suburbs were tested. The results showed that Taraxracum mongolicum, Solanum nigrum and Conyza canadensis could strongly tolerate single Cd and Cd-Pb-Cu-Zn combined pollution, had high Cd-accumulative ability, and generally possessed basic characteristics of hyperaccumulators. Because there are synergic and antagonistic effects among Cd, Pb, Cu and Zn, singlefactor pollution tests should be done as well as combined pollution tests during the identification of hyperaccumulators to ensure the efficiency of phytoremediation and the practical significance of hyperaccumulators identified. The field pot-culture experiment should be a new tentative method to screen out accumulative and tolerant species in view of its obvious advantages such as simple operation, low cost, and easy identification of investigated plants.

  6. INTEGRATED WEED CONTROL IN MAIZE.

    Science.gov (United States)

    Latré, J; Dewitte, K; Derycke, V; De Roo, B; Haesaert, G

    2015-01-01

    Integrated pest management has been implemented as a general practice by EU legislation. As weed control actually is the most important crop protection measure in maize for Western Europe, the new legislation will have its impact. The question is of course which systems can be successfully implemented in practice with respect to labour efficiency and economical parameters. During 3 successive growing seasons (2007, 2008, 2009) weed control in maize was evaluated, the main focus was put on different techniques of integrated weed control and was compared with chemical weed control. Additionally, during 4 successive growing seasons (2011, 2012, 2013 and 2014) two objects based on integrated weed control and two objects based on mechanical weed control were compared to about twenty different objects of conventional chemical weed control. One of the objects based on mechanical weed control consisted of treatment with the flex-tine harrow before and after emergence in combination with chemical weed control at a reduced rate in 3-4 leave stage. The second one consisted of broadcast mechanical treatments before and after emergence followed by a final in-row application of herbicides and an inter-row cultivation at 6-7(8) leave stage. All trials were conducted on the Experimental farm of Bottelare HoGent-UGent on a sandy loam soil. Maize was growing in 1/3 crop rotation. The effect on weed growth as well as the economic impact of the different applications was evaluated. Combining chemical and mechanical weed control is a possible option in conventional farming but the disadvantages must be taken into account. A better planned weed control based on the real present weed-population in combination with a carefully thought-out choice of herbicides should also be considered as an IPM--approach.

  7. WeedML: a Tool for Collaborative Weed Demographic Modeling

    OpenAIRE

    Holst, Niels

    2010-01-01

    WeedML is a proposed standard to formulate models of weed demography, or maybe even complex models in general, that are both transparent and straightforward to re-use as building blocks for new models. The paper describes the design and thoughts behind WeedML which relies on XML and object-oriented systems development. Proof-of-concept software is provided as open-source C++ code and executables that can be downloaded freely.

  8. Morphological Comparisons Between Xiphinema rivesi Daimasso and X. americanum Cobb Populations from the Eastern United States.

    Science.gov (United States)

    Wojtowlcz, M R; Golden, A M; Forer, L B; Stouffer, R F

    1982-10-01

    Though in the past Xiphinema americanum has been the most commonly reported dagger nematode in the eastern United States, our studies revealed the presence in Pennsvlvania of a previously unrecognized and unreported species related to X. americanum, Morphometric data and photomicrographs establish the identity of this form as X. rivesi and show expected variations in populations of this species from various locations. Similar data and illustrations are given for X. americanum populations from Pennsylvania and other areas, showing variations and relationships. Xiphinema rivesi is widely distributed in the fruit producing area of south-central Pennsylvania and is also reported herein from raspberry in Vermont and apple in Maryland and New York. This species is frequently found in fruit growing areas of Pennsylvania associated with tomato ringspot virus-induced diseases and is also found associated with corn, bluegrass sod, and alfalfa.

  9. Potencial de espécies utilizadas como adubo verde no manejo integrado de plantas daninhas Potential of species used as green manure in the integrated weed management

    Directory of Open Access Journals (Sweden)

    E.A.L. Erasmo

    2004-09-01

    Full Text Available O presente trabalho foi conduzido na Estação Experimental da Universidade Federal do Tocantins, Gurupi-TO, Brasil. O experimento foi instalado com o objetivo de avaliar durante 60 dias, em campo, a interferência de oito espécies utilizadas freqüentemente como adubos verdes (Mucuna aterrima, Mucuna pruriens, Crotalaria ochroleuca, Crotalaria spectabilis, Canavalia ensiformis, Cajanus cajan, Pennisetum americanum e Sorghum bicolor, híbrido BR304 sobre a comunidade infestante. As espécies de plantas daninhas mais freqüentes na área do experimento foram: Digitaria horizontalis, Hyptis lophanta e Amaranthus spinosus. Foram realizadas amostragens aos 15, 30, 45 e 60 dias após a formação da cobertura, utilizando um quadrado de amostragem equivalente a 0,25 m². As plantas daninhas foram devidamente identificadas, coletadas, secas e pesadas. O delineamento experimental utilizado foi inteiramente casualizado e constou de nove tratamentos, com quatro repetições cada. Verificou-se que as espécies C. spectabilis, S. bicolor, C. ochroleuca, M. aterrima e M. pruriens reduziram significativamente o número e o peso da matéria seca da população das plantas daninhas avaliadas (D. horizontalis, H. lophanta e A. Spinosus, principalmente as duas últimas, enquanto P. americanum mostrou-se a menos eficiente nesse aspecto.This work was carried out at the Experimental Station of the University of Tocantins, Gurupi-TO, Brazil, to evaluate the interference of eight species frequently used as green manure (Mucuna aterrima, Mucuna pruriens, Crotalaria ochroleuca, Crotalaria spectabilis, Canavalia ensiformis, Cajanus cajan, Pennisetum americanum and Sorghum bicolor, hybrid BR304 in the weed community, for sixty days under field conditions. The most frequent weed species in the experimental area were Digitaria horizontalis, Hyptis lophanta and Amaranthus spinosus. Samplings were made at 15, 30, 45 and 60 days after formation of green manure covering, using

  10. Pseudomonas syringae pv. phaseolicola isolated from weeds in bean crop fields.

    Science.gov (United States)

    Fernández-Sanz, A M; Rodicio, M R; González, A J

    2016-04-01

    Pseudomonas syringae pv. phaseolicola, the causative agent of halo blight in common bean (Phaseolus vulgaris L.), was isolated from weeds associated with bean crops in Spain. The bacterium was recovered from Fumaria sp, Mercurialis annua, Solanum nigrum and Sonchus oleraceus. Ps. s. pv. phaseolicola had previously been isolated from leguminous plants and S. nigrum, but to our knowledge, this is the first time it was recovered from the other three species. The isolates were phenotypically and genetically characterized, and they were compared with isolates recovered from common beans. Five different genotypic profiles were detected by PmeI-PFGE, two of them being of new description. Weed isolates were as pathogenic on bean plants as bean isolates, but they were not pathogenic on S. nigrum. Regarding the survival of the pathogen in weeds, Ps. s. pv. phaseolicola was isolated from So. oleraceus 11 weeks after the end of the bean crop. These results strongly support the idea of weeds as a potential source of inoculum for halo blight in bean. It has traditionally been considered that the main source of inoculum of Pseudomonas syringae pv. phaseolicola causing halo blight disease in Phaseolus vulgaris are the bean seeds, and that the host range of the bacterium is almost restricted to leguminous plants. In this study, the bacterium was recovered from four nonleguminous weed species collected in bean fields, and its permanence in weeds for at least 11 weeks after the harvesting of the beans was demonstrated. We have also proved that the strains isolated from weeds were pathogenic on bean plants. Accordingly, the host range of Ps. s. pv. phaseolicola could be broader than previously thought and weeds appear to be acting as a reservoir of the pathogen until the next crop. © 2016 The Society for Applied Microbiology.

  11. Discovery of filarial nematode DNA in Amblyomma americanum in Northern Virginia.

    Science.gov (United States)

    Henning, Tyler C; Orr, John M; Smith, Joshua D; Arias, Jorge R; Rasgon, Jason L; Norris, Douglas E

    2016-03-01

    Ticks collected in 2011 were screened for the presence of filarial nematode genetic material, and positive samples were sequenced for analysis. Monanema-like filarial nematode DNA was recently discovered in Amblyomma americanum in northern Virginia, marking the first time genetic material from this parasite has been discovered in ticks in the state. Phylogenetic analysis revealed that this material was directly related to a previously discovered filarial nematode in A. americanum populations in Maryland as well as recently identified parasites in Ixodes scapularis from southern Connecticut. Further study is warranted to visually confirm the presence of these nematodes, characterize their distribution, and determine if these ticks are intermediate hosts.

  12. Effect of Three Plant Species on Population Densities of Xiphinema americanum and X. rivesi.

    Science.gov (United States)

    Georgi, L L

    1988-07-01

    A taxonomic revision of the Xiphinema americanum species complex has necessitated a reexamination of the host range of species in the complex before recommendations can be made with confidence on the likelihood that specific crops will be damaged. Toward this end, populations of X. americanum and X. rivesi collected from apple orchards in eastern and western New York state were evaluated after 3 months in pots planted with cucumber, apple, or dandelion seedlings. Eastern and western New York populations of both nematode species declined on cucumber but increased to similar final densities on apple and dandelion.

  13. Diversity of Xiphinema americanum-group Species and Hierarchical Cluster Analysis of Morphometrics.

    Science.gov (United States)

    Lamberti, F; Ciancio, A

    1993-09-01

    Of the 39 species composing the Xiphinema americanum group, 14 were described originally from North America and two others have been reported from this region. Many species are very similar morphologically and can be distinguished only by a difficult comparison of various combinations of some morphometric characters. Study of morphometrics of 49 populations, including the type populations of the 39 species attributed to this group, by principal component analysis and hierarchical cluster analysis placed the populations into five subgroups, proposed here as the X. brevicolle subgroup (seven species), the X. americanum subgroup (17 species), the X. taylori subgroup (two species), the X. pachtaicum subgroup (eight species), and the X. lambertii subgroup (five species).

  14. Restriction Fragment Length Polymorphism Separates Species of the Xiphinema americanum Group.

    Science.gov (United States)

    Vrain, T C

    1993-09-01

    The Xiphinema americanum group of species is responsible for vectoring several important virus diseases to perennial crops. Variability of transmission of viruses by different species, and difficulties in separating species by morphometric measurements alone, make it essential to reassess the taxonomic position of several species in the group. The measurement of DNA sequence variability is a sensitive assay that can re-evaluate the separation of species and populations from each other. This study describes how an RFLP approach, in which the restriction sites in transcribed spacers of ribosomal repeats were detected, confirmed the separation of 16 populations of these species into X. americanum, X. rivesi, X. pacificum, and X. bricolensis.

  15. Weeding with transgenes.

    Science.gov (United States)

    Duke, Stephen O

    2003-05-01

    Transgenes promise to reduce insecticide and fungicide use but relatively little has been done to significantly reduce herbicide use through genetic engineering. Recently, three strategies for transgene utilization have been developed that have the potential to change this. These are the improvement of weed-specific biocontrol agents, enhancement of crop competition or allelopathic traits, and production of cover crops that will self-destruct near the time of planting. Failsafe risk mitigation technologies are needed for most of these strategies.

  16. The Overmyer mastodon (Mammut americanum) from Fulton County, Indiana

    Science.gov (United States)

    Woodman, N.; Branstrator, J.W.

    2008-01-01

    In June 1978 the partial skeleton of an American mastodon, Mammut americanum, was salvaged from a drainage ditch in Fulton County, north-central Indiana. The remains were recovered mostly from ca. 170-260 cm below the current land surface in marl overlain by peat and peaty marl. The stratigraphy of the site indicates that the remains were deposited in a small, open-water pond that subsequently filled. The skeleton, which is 41-48% complete, is that of a mature female, ca. 30-34 y old at death based on dental eruption and wear. Postcranial bone measurements indicate that this individual was relatively large for a female. Radiocarbon dating of wood from under the pelvis of the mastodon provided a maximum date of 12,575 ? 260 14C y BP [15,550-13,850 cal y BP] for the animal, which is up to 2575 14C y before the species is believed to have become extinct. Pollen samples from the site corroborate the interpretation that the regional climate was cooler and more humid than at present and supported a mixed spruce-deciduous parkland assemblage. The relatively small size of the molars of this and other mastodons from Indiana supports the hypothesis that late-glacial mastodons - just prior to their extinction - were smaller in size relative to earlier, full-glacial conspecifics. The relationship between molar size and body size is not clear, however, and there may be geographical factors as well as a temporal influence to size variation in these animals.

  17. Parasitism of Xiphinema rivesi and X. americanum by Zoosporic Fungi.

    Science.gov (United States)

    Jafee, B A

    1986-01-01

    Living Xiphinema americanum (Xa) and X. rivesi (Xr) extracted from soil samples and stored for 1-5 days at 4 or 20 C contained aseptate fungal hyphae. The fungi directly penetrated the nematode's cuticle from spores encysted near the head. Penetration through the stoma, vulva, or anus was rare. Catenaria anguillulae (Cat), Lagenidium caudatura (Lag), Aphanomyces sp. (Aph), and Leptolegnia sp. (Lep) were isolated into pure culture from infected nematodes. The pathogenicity of these zoosporic fungi was determined by incubating mixed freshly extracted Xa and Xr in 2% soil extract (pH = 6.7, conductivity = 48 mumhos, 20 +/- 2 C) containing zoospores obtained from single-spore isolates. After 4 days, Cat, Lag, Aph, and Lep had infected 78, 18, 13, and 22%, respectively, of the nematodes. Both Xa and Xr were infected by every fungus; however, the relative susceptibility of Xa and Xr to these fungi was not determined. All noninoculated control nematodes remained uninfected and alive. In a second experiment, parasitism of Xa and Xr by Aph and Lep was increased when nematodes were incubated in 2% soil extract for 4 days before exposure to zoospores. In a third experiment, parasitism of Xa and Xr by Cat was greater in diluted saturation soil extract (conductivity = 100-400 mumhos) than in undiluted saturation extract (conductivity = 780 mumhos). Cat produced small zoospores (4-mum-d), bulbous infection hyphae, and assimilative hyphae of varying diameters in nematodes, whereas Lag, Aph, and Lep produced large zoospores (8-mum-d) and tubular, uniform infection and assimilative hyphae in nematodes.

  18. A revision of the Dulcamaroid Clade of Solanum L. (Solanaceae

    Directory of Open Access Journals (Sweden)

    Sandra Knapp

    2013-05-01

    Full Text Available The Dulcamaroid clade of Solanum contains 45 species of mostly vining or weakly scandent species, including the common circumboreal weed Solanum dulcamara L. The group comprises members of the previously recognised infrageneric groupings sect. Andropedas Rusby, sect. Californisolanum A. Child, sect. Dulcamara (Moench Dumort., sect. Holophylla (G.Don Walp., sect. Jasminosolanum (Bitter Seithe, sect. Lysiphellos (Bitter Seithe, subsect. Nitidum A.Child and sect. Subdulcamara Dunal. These infrageneric groups are not monophyletic as traditionally recognised, and the complex history of the classification of the dulcamaroid solanums is reviewed. Many of the species in the clade are quite variable morphologically; plants are shrubs, herbaceous vines or woody canopy lianas, and habits can vary between these states in a single locality. Variation in leaf shape and pubescence density and type is also extreme and has lead to the description of many minor morphological variants as distinct species. The flowers of members of the group are generally very showy, and several species (e.g., S. crispum Ruiz & Pav., S. laxum Spreng., S. seaforthianum Andrews are popular ornamental plants that have occasionally escaped from cultivation and become naturalised. The clade is here divided into five morphologically and geographically delimited species groups to facilitate further study. One new species from southern Ecuador, Solanum agnoston S.Knapp sp. nov., is described here. Full descriptions and synonymies (including designations of lectotypes or neotypes, preliminary conservation assessments, illustrations, distribution maps, and an extensive list of localities are provided for all species.

  19. Weeding Library Collections: Library Weeding Methods. Fourth Edition.

    Science.gov (United States)

    Slote, Stanly J.

    Weeding is one of the best ways to make long-term improvements to library collections, but it is also a difficult and sometimes painful task. In the tradition of previous editions, this book guides librarians in the process of methodical and efficient weeding. The book shows how to identify core collections versus the weedable items. The approach…

  20. Solanum nigrum Linn.- A review

    Directory of Open Access Journals (Sweden)

    T S Mohamed Saleem

    2009-01-01

    Full Text Available Solanum nigrum Linn. (Solanaceae commonly known as ′Black nightshade′ that have been extensively used in traditional medicine in India and other parts of world to cure liver disorders, chronic skin ailments (psoriasis and ringworm, inflammatory conditions, painful periods, fevers, diarrhoea , eye diseases, hydrophobia, etc. It has been found that Solanum nigrum contains the substances, such as total alkaloid, steroid alkaloid, steroidal saponins and glycoprotein, exhibiting anti-tumor activity. In Indian traditional medicine, the plant is used as a hepatoprotective agent. In this review, we have explored the phyto-pharmacological properties of the Solanum nigrum plant and compiled its vast pharmacological applications to comprehend and synthesize the subject of its potential image of multipurpose medicinal agent.

  1. Rickettsia parkeri Transmission to Amblyomma americanum by Cofeeding with Amblyomma maculatum (Acari: Ixodidae) and Potential for Spillover.

    Science.gov (United States)

    Wright, Chelsea L; Sonenshine, Daniel E; Gaff, Holly D; Hynes, Wayne L

    2015-09-01

    Amblyomma americanum (L.) is a human-biting ixodid tick distributed throughout much of the southeastern United States. Rickettsia parkeri is a member of the spotted fever group rickettsiae and causes a febrile illness in humans commonly referred to as "Tidewater spotted fever" or "R. parkeri rickettsiosis." Although the Gulf Coast tick, Amblyomma maculatum Koch, is the primary vector of R. parkeri, a small proportion of A. americanum have also been shown to harbor R. parkeri. The purpose of this investigation was to determine whether R. parkeri is spilling over into A. americanum in eastern Virginia and also to determine through laboratory experiments, whether A. americanum can acquire R. parkeri by cofeeding alongside infected ticks. Of 317 wild-caught, flat adult A. americanum tested from 29 counties and independent cities in coastal Virginia, a single female A. americanum was positive for R. parkeri, suggesting that R. parkeri is spilling over into this species, but at very low rates (Rickettsia amblyommii, however, were less likely to acquire R. parkeri, suggesting that infection with R. amblyommii may prevent R. parkeri from establishing infection in A. americanum.

  2. Interference of allelopathic wheat with different weeds.

    Science.gov (United States)

    Zhang, Song-Zhu; Li, Yong-Hua; Kong, Chui-Hua; Xu, Xiao-Hua

    2016-01-01

    Interference of allelopathic wheat with weeds involves a broad spectrum of species either independently or synergistically with competitive factors. This study examined the interference of allelopathic wheat with 38 weeds in relation to the production of allelochemical 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) in wheat with and without root-root interactions. There were substantial differences in weed biomass and DIMBOA concentration in wheat-weed coexisting systems. Among 38 weeds, nine weeds were inhibited significantly by allelopathic wheat but the other 29 weeds were not. DIMBOA levels in wheat varied greatly with weed species. There was no significant relationship between DIMBOA levels and weed suppression effects. Root segregation led to great changes in weed inhibition and DIMBOA level. Compared with root contact, the inhibition of eight weeds was lowered significantly, while significantly increased inhibition occurred in 11 weeds with an increased DIMBOA concentration under root segregation. Furthermore, the production of DIMBOA in wheat was induced by the root exudates from weeds. Interference of allelopathic wheat with weeds not only is determined by the specificity of the weeds but also depends on root-root interactions. In particular, allelopathic wheat may detect certain weeds through the root exudates and respond by increasing the allelochemical, resulting in weed identity recognition. © 2015 Society of Chemical Industry.

  3. Efficacy of granular deltamethrin against Ixodes scapularis and Amblyomma americanum (Acari: Ixodidade) nymphs.

    Science.gov (United States)

    Schulze, T L; Jordan, R A; Hung, R W; Taylor, R C; Markowski, D; Chomsky, M S

    2001-03-01

    A single barrier application of granular deltamethrin to the woodland edges of a forested residential community in late spring significantly reduced the abundance of Ixodes scapularis Say nymphs. The application also suppressed the population of Amblyomma americanum (L.) nymphs, which recently became established in the study area. The efficacy of deltamethrin is compared with other commonly used acaricides.

  4. Epidemiology of Xiphinema americanum and Tomato ringspot virus on Red Raspberry, Rubus idaeus.

    Science.gov (United States)

    The population dynamics and the ability of Xiphinema americanum to transmit Tomato ringspot virus (ToRSV) are poorly understood in the raspberry pathosystem. Soil samples were collected monthly from 1999 through 2002 in a ToRSV infected 'Willamette' red raspberry field in Clark County, WA, USA. Pop...

  5. An acarologic survey and Amblyomma americanum distribution map with implications for tularemia risk in Missouri

    Science.gov (United States)

    Brown, H.E.; Yates, K.F.; Dietrich, G.; MacMillan, K.; Graham, C.B.; Reese, S.M.; Helterbrand, Wm. S.; Nicholson, W.L.; Blount, K.; Mead, P.S.; Patrick, S.L.; Eisen, R.J.

    2011-01-01

    In the United States, tickborne diseases occur focally. Missouri represents a major focus of several tickborne diseases that includes spotted fever rickettsiosis, tularemia, and ehrlichiosis. Our study sought to determine the potential risk of human exposure to human-biting vector ticks in this area. We collected ticks in 79 sites in southern Missouri during June 7-10, 2009, which yielded 1,047 adult and 3,585 nymphal Amblyomma americanum, 5 adult Amblyomma maculatum, 19 adult Dermacentor variabilis, and 5 nymphal Ixodes brunneus. Logistic regression analysis showed that areas posing an elevated risk of exposure to A. americanum nymphs or adults were more likely to be classified as forested than grassland, and the probability of being classified as elevated risk increased with increasing relative humidity during the month of June (30-year average). Overall accuracy of each of the two models was greater than 70% and showed that 20% and 30% of the state were classified as elevated risk for human exposure to nymphs and adults, respectively. We also found a significant positive association between heightened acarologic risk and counties reporting tularemia cases. Our study provides an updated distribution map for A. americanum in Missouri and suggests a wide-spread risk of human exposure to A. americanum and their associated pathogens in this region. Copyright ?? 2011 by The American Society of Tropical Medicine and Hygiene.

  6. Neuronal projections from the Haller's organ and palp sensilla to the synganglion of Amblyomma americanum

    Science.gov (United States)

    The present study was conducted to elucidate the neuronal pathways between peripheral olfactory and taste sensilla and the synganglion in an Ixodidae tick species. The tarsus of the front legs (olfactory nerves) and the fourth palpal segment (gustatory nerves) of unfed Amblyomma americanum males and...

  7. Weed Identification Field Training Demonstrations.

    Science.gov (United States)

    Murdock, Edward C.; And Others

    1986-01-01

    Reviews efforts undertaken in weed identification field training sessions for agriprofessionals in South Carolina. Data over a four year period (1980-1983) revealed that participants showed significant improvement in their ability to identify weeds. Reaffirms the value of the field demonstration technique. (ML)

  8. Weed Identification Field Training Demonstrations.

    Science.gov (United States)

    Murdock, Edward C.; And Others

    1986-01-01

    Reviews efforts undertaken in weed identification field training sessions for agriprofessionals in South Carolina. Data over a four year period (1980-1983) revealed that participants showed significant improvement in their ability to identify weeds. Reaffirms the value of the field demonstration technique. (ML)

  9. Some Weeds Community Percent in Response to Pumice Application on Soil under Water Stress Conditions

    Directory of Open Access Journals (Sweden)

    Davoud Zarehaghi

    2016-02-01

    Full Text Available A factorial experiment (using RCBD design with three replications was conducted in 2014 at the University of Tabriz-Iran, in order to determine the effects of pumice application (P1, P2, P3 and P4: control, 30, 60 and 90 tons per ha on soil and water stress (I1, I2 and I3: 100%, 70% and 50% water requirement calculated from class A pan, respectively on dominante weeds community percent. Results showed that community percent of weed species changed as a result of water stress and pumice application on soil. Distributions of Chenopodium album and Malva sylvestris were sensitive to water stress but, Amaranthus retroflexus and Solanum nigrum were neutral to water stress. In contrast, Amaranthus retroflexus, Cardaria draba, Setaria viridis, Sisymbrium irio, Xanthium strumarium, Convolvulus arvensis and Salsola rigida distribution were resistant to water stress. Community percent of Chenopodium album as sensitive species to water stress and Salsola rigida as resistance species to water stress positively affected by pumice application especially under water stress condition. Amaranthus retroflexus, Xanthium strumarium and Convolvulus arvensis were positively affected by pumice application under well and limited water supply conditions. In contrast, Cardaria draba, Sisymbrium irio and Solanum nigrum negatively affected by pumice under water stress and it had positive effect on community of these species under well watering conditions. Thus, application of pumice and water stress are two factors which change weed community precent.

  10. Using laser to measure stem thickness and cut weed stems

    DEFF Research Database (Denmark)

    Heisel, T.; Schou, Jørgen; Andreasen, C.

    2002-01-01

    Stem thickness of the weed Solanum nigrum and the crop sugarbeet was determined with a He-Ne laser using a novel non-destructive technique measuring stem shadow. Thereafter, the stems were cut close to the soil surface with a CO2 laser. Treatments were carried out on pot plants, grown...... in the greenhouse, at two different growth stages, and plant dry matter was measured 2-5 weeks after treatment. The relationship between plant dry weight and laser energy was analysed using two different non-linear dose-response regression models; one model included stem thickness as a variable, the other did not....... A binary model was also tested. The non-linear model incorporating stem thickness described the data best, indicating that it would be possible to optimize laser cutting by measuring stem thickness before cutting. The general tendency was that more energy was needed the thicker the stem. Energy uses...

  11. Weeding the School Library Media Collection.

    Science.gov (United States)

    School Library Media Quarterly, 1984

    1984-01-01

    This document prepared by Calgary Board of Education, Calgary, Alberta, Canada, discusses a systematic approach to strengthening the library media collection. A statement of principle, what to weed, specific guides to weeding (by Dewey Decimal classification and type of material), what not to weed, procedures, and weeding follow-up are…

  12. A new perspective with weed management

    Science.gov (United States)

    No-till cropping systems are increasing land productivity. Herbicides are a crucial tool for weed management in no-till, but weed resistance is decreasing control efficacy and increasing input costs. Producers are seeking a broader perspective with weed management. One approach is to disrupt weed...

  13. 7 CFR 201.50 - Weed seed.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Weed seed. 201.50 Section 201.50 Agriculture... REGULATIONS Purity Analysis in the Administration of the Act § 201.50 Weed seed. Seeds (including bulblets or tubers) of plants shall be considered weed seeds when recognized as weed seeds by the law or rules and...

  14. 7 CFR 201.15 - Weed seeds.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Weed seeds. 201.15 Section 201.15 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.15 Weed seeds. The percentage of weed seeds shall include seeds of plants considered weeds in the State into which the seed is offered for transportation or...

  15. Applicator Training Manual for: Aquatic Weed Control.

    Science.gov (United States)

    Herron, James W.

    The aquatic weeds discussed in this manual include algae, floating weeds, emersed weeds, and submerged weeds. Specific requirements for pesticide application are given for static water, limited flow, and moving water situations. Secondary effects of improper application rates and faulty application are described. Finally, techniques of limited…

  16. Applicator Training Manual for: Aquatic Weed Control.

    Science.gov (United States)

    Herron, James W.

    The aquatic weeds discussed in this manual include algae, floating weeds, emersed weeds, and submerged weeds. Specific requirements for pesticide application are given for static water, limited flow, and moving water situations. Secondary effects of improper application rates and faulty application are described. Finally, techniques of limited…

  17. Weeding the School Library Media Collection.

    Science.gov (United States)

    School Library Media Quarterly, 1984

    1984-01-01

    This document prepared by Calgary Board of Education, Calgary, Alberta, Canada, discusses a systematic approach to strengthening the library media collection. A statement of principle, what to weed, specific guides to weeding (by Dewey Decimal classification and type of material), what not to weed, procedures, and weeding follow-up are…

  18. Evaluation of DEET and eight essential oils for repellency against nymphs of the lone star tick, Amblyomma americanum (Acari: Ixodidae)

    Science.gov (United States)

    Eight commercially available essential oils (oregano, clove, thyme, vetiver, sandalwood, cinnamon, cedarwood, and peppermint) were evaluated for repellency against host-seeking nymphs of the lone star tick, Amblyomma americanum. Concentration- repellency response was established using the vertical ...

  19. Experimental Infection of Adult and Juvenile Coyotes with Domestic Dog and Wild Coyote Isolates of Hepatozoon americanum (Apicomplexa: Adeleorina)

    National Research Council Canada - National Science Library

    Garrett, Jennifer Jane; Kocan, A. Alan; Reichard, Mason V; Panciera, Roger J; Bahr, Robert J; Ewing, Sidney A

    2005-01-01

    .... All coyotes exposed to H. americanum became infected, regardless of isolate source, and all exhibited mild to moderate clinical disease that simulated American canine hepatozoonosis in naturally infected dogs...

  20. Study on infestation levels and spatial distributions of Amaranthus blitoides, Chenopodium album and Solanum nigrum in corn field

    Directory of Open Access Journals (Sweden)

    elmira mohamad vand

    2009-06-01

    Full Text Available For increasing the effectiveness of weed management and more understanding of weed population dynamics, spatial distribution needs to more attentions. Infestation levels and spatial distributions of Amaranthus blitoides, Chenopodium album and Solanum nigrum were studied in four 10x30 m corn fields. N-fertilizer was applied in two method of whole application at the time of corn planting (T1 and T2 and equal split application at the time of corn planting and at six-leaf stage (T3 and T4. One of either fields with the same method of N-fertilizer application, received herbicide too (T1 and T3. Weeds Samples were taken four times at the intersection of 2.5m square grids with 23days interval. The first sample was taken June 24, before top-dressing and herbicide application in related plots. For studying weed spatial distribution, the parameters of appropriate semivariogram model were calculated and weed contour maps were constructed by using kriging. The weed semivariograms fitted spherical and exponential models, over four sampling times and fields and spatial autocorrelation during growing season, was moderate to strong. In early growing season, Amaranthus blitoides was the dominant weed species in all fields, but lower density was recorded for Chenopodium album and Solanum nigrum. At the first sampling time, mean density of A. blitoides and S. nigrum in fields with split application of N-fertilizer was respectively more- and less than fields with whole application of N-fertilizer. In the case of C. album an evident difference wasn’t observed. Herbicide application in related plots considerably reduced the density of three mentioned species; however density never became zero. In the majority of cases the lack of herbicide application causes to increase in population density at the second sampling time. Spatial structure was observed in all three species and study on contour maps confirmed the existence of patches that the density was high in their

  1. AN UPDATED REVIEW ON MOLECULAR GENETICS, PHYTOCHEMISTRY, PHARMACOLOGY AND PHYSIOLOGY OF BLACK NIGHTSHADE (SOLANUM NIGRUM

    Directory of Open Access Journals (Sweden)

    Ashwani Kumar*, S. Sagwal, Niketa and S. Rani

    2012-09-01

    Full Text Available This article reviews, connected the gap between the folkloric use of Solanum nigrum and the results of evidence based experiments. Although Solanum nigrum is a rich source of one of plants most dreaded toxins solanine, it has appreciably monstrated its potential as a reservoir of antioxidants having hepatoprotective, anti-tumor, cytostatic, anti-convulsant, anti-ulcerogenic and anti-inflammatory.effects. The review encompasses in-vitro, in vivo and clinical studies done on Solanum nigrum, while examining.whether or not correct scientific measures have been taken in generating experimental evidences for its traditional uses. This review would afford research scientist to know how much is known and what is left undone in the investigation of Solanum nigrum. The compounds considered in this revieware flavonoids and other phenolics, alkaloids (especially indole terpenoid and purine alkaloids, essential oils and other terpenoids, cannabinoids, lucosinolates and isothiocyanates, and compounds having human hormone activity. The review concludes with a discussion of the possible evolutionary mechanisms that have led to the evolution of UV-B regulation of secondary metabolite accumulation. Many Ayurveda philosophers and healers praised about the properties of this plant and utilized in various disorders. Here, a review made on the screening of Solanum nigrum for various activities. It is found that the drug is very potential and can be used for various applications as mentioned in Ayurveda. Black nightshade grows as a weed, found in the dry parts of India and other parts of the world. It has a medicinal usage and has been used as a traditional folk medicine for treating various ailments such as pain, fever and liver disorders. Generally, black nightshade is very rich in nutritive values, which are capable of supplying minerals, vitamins, hormones and proteins. This herb elaborates a wide variety of medicinal properties such as anticancer, antioxidant

  2. Effect of different input management on weed composition, diversity and density of corn field

    Directory of Open Access Journals (Sweden)

    Surur Khoramdel

    2016-04-01

    Full Text Available In order to investigate the effects of input intensity on species diversity, composition and density of weeds in corn (Zea mays L., an experiment was conducted based on a randomized complete block design with three replications at the Agricultural Research Station, Ferdowsi University of Mashhad, Iran during the year 2009. Treatments included low input, medium input and high input systems. Low input received 30 tonha-1or 30 tonha-1 compost, zero tillage and hand weeding (twice. Medium input was based on 15 tonha-1 manure, 150 kgha-1 urea as chemical fertilizer, twice tillage operations and 2, 4-D (1.5 Lha-1, at five leaves emergence as an herbicide and hand weeding (once. High input received 300 kgha-1 urea, four tillage operations and Paraquat (2 Lha-1, after planting and 2, 4-D (1.5 Lha-1, at five leaves emergence. Manure and compost were applied in the planting time. Weed samplings were done in three stages (early, mid and late growing season. Results indicated that the highest and the lowest weed species diversity and density were observed in low input based on manure and high input systems, respectively. The highest range of weed relative density was obtained for black nightshade (Solanum nigrum with 9.09-75.00%. The highest number of species was observed in low input based on manure. Also, management practices affected weed dry matter and diversity indices. The highest and the lowest amounts of weed dry matter were observed in low input based on manure and high input systems, respectively. In the first, second and the third stages of sampling, the maximum and the minimum amounts of Margalef index were observed in low input based on manure (with 5.3, 5.4 and 3.3, respectively and high input systems (with 0.8, 2.3 and 2.6, respectively. In the first, second and the third stages of sampling, the highest and the lowest values of Shannon index were observed in low input based on manure (with 0.6, 0.7 and 0.5 respectively and high input (with 0

  3. Experimental infection of adult and juvenile coyotes with domestic dog and wild coyote isolates of Hepatozoon americanum (Apicomplexa: Adeleorina).

    Science.gov (United States)

    Garrett, Jennifer Jane; Kocan, A Alan; Reichard, Mason V; Panciera, Roger J; Bahr, Robert J; Ewing, Sidney A

    2005-07-01

    Each of five adult and four juvenile coyotes (Canis latrans) was exposed to an oral dose of 50 Hepatozoon americanum oocysts recovered from Amblyomma maculatum ticks that previously fed on either naturally infected domestic dogs (Canis familiaris) or naturally infected wild coyotes. All coyotes exposed to H. americanum became infected, regardless of isolate source, and all exhibited mild to moderate clinical disease that simulated American canine hepatozoonosis in naturally infected dogs. At 100 days postexposure, parasitemia was greater in juvenile than adult coyotes (0.9% and 0.3%, respectively); radiographic imaging of femurs revealed moderate exostosis in all juveniles and mild to moderate new bone growth in four of five (80%) adult coyotes. Gross postmortem analysis of bone lesions demonstrated variation between age groups of coyotes but not between isolates of H. americanum. Microscopic evaluation of skeletal muscle revealed that parasite-induced lesions were significantly more numerous (t = 5.0, df = 7, P = 0.001) in juvenile than adult coyotes. Results of this study indicate that juvenile and adult coyotes are equally susceptible to experimental infection with H. americanum isolated from domestic dog and wild coyote sources. The age of coyotes at the time of exposure, and possibly the number of H. americanum oocysts ingested, might influence morbidity and mortality, but it appears that both adult and juvenile coyotes could be reservoirs of H. americanum.

  4. Amblyomma americanum as a Bridging Vector for Human Infection with Francisella tularensis.

    Directory of Open Access Journals (Sweden)

    Rinosh J Mani

    Full Text Available The γ-proteobacterium Francisella tularensis causes seasonal tick-transmitted tularemia outbreaks in natural rabbit hosts and incidental infections in humans in the south-central United States. Although Dermacentor variabilis is considered a primary vector for F. tularensis, Amblyomma americanum is the most abundant tick species in this endemic region. A systematic study of F. tularensis colonization of A. americanum was undertaken to better understand its potential to serve as an overwintering reservoir for F. tularensis and as a bridging vector for human infections. Colony-reared A. americanum were artificially fed F. tularensis subspecies holarctica strain LVS via glass capillaries and colonization levels determined. Capillary-fed larva and nymph were initially infected with 10(4 CFU/tick which declined prior to molting for both stages, but rebounded post-molting in nymphs and persisted in 53% at 10(3 to 10(8 CFU/nymph at 168 days post-capillary feeding (longest sampling time in the study. In contrast, only 18% of adults molted from colonized nymphs maintained LVS colonization at 10(1 to 10(5 CFU/adult at 168 days post-capillary feeding (longest sampling time. For adults, LVS initially colonized the gut and disseminated to salivary glands by 24 h and had an ID50 of <5CFU in mice. Francisella tularensis infected the ovaries of gravid females, but transmission to eggs was infrequent and transovarial transmission to hatched larvae was not observed. The prolonged persistence of F. tularensis in A. americanum nymphs supports A. americanum as an overwintering reservoir for F. tularensis from which seasonal epizootics may originate; however, although the rapid dissemination of F. tularensis from gut to salivary glands in adults A. americanum is compatible with intermittent feeding adult males acting as bridging vectors for incidental F. tularensis infections of humans, acquisition of F. tularensis by adults may be unlikely based on adult feeding

  5. [Alfalfa Planting as weed control

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a letter to farming cooperators regarding the stipulations surrounding alfalfa plantings in lieu of small grain plantings to provide weed control,...

  6. Xiphinema americanum Cobb, 1913 (Dorylaimida: Longidoridae: espécie-praga quarentenária para o Brasil Xiphinema americanum Cobb, 1913 (Dorylaimida: Longidoridae: quarantine pest for Brazil

    Directory of Open Access Journals (Sweden)

    Giovani Greigh de Brito

    2005-02-01

    Full Text Available Diversos aspectos referentes à espécie-praga quarentenária Xiphinema americanum, incluindo características taxonômicas, distribuição geográfica, plantas hospedeiras, aspectos bioecológicos, potencial de transmissão de viroses e medidas de controle, entre outros, foram abordados nesta revisão. A dificuldade encontrada pelos especialistas na correta identificação deste nematóide quarentenário muitas vezes determina que X. americanum seja confundido com outras espécies pertencentes ao mesmo gênero. Esta praga, além de utilizar como hospedeiras várias espécies de plantas e encontrar-se estabelecida em diversas regiões do globo terrestre, constitui-se em um agente transmissor de viroses, dentre as quais algumas são também consideradas quarentenárias para vários países, incluindo o Brasil. Considerando a sua ampla distribuição geográfica somada ao seu alto potencial de transmissão de viroses, o conhecimento dos aspectos abordados nesta revisão pode auxiliar na redução do risco de introdução deste nematóide quarentenário á áreas indenes no Brasil.Different aspects concerning the quarantine pest X. americanum, including taxonomic characteristics, world distribution, host plants, viruses transmission potential, control methods and others, were reviewed. The difficulty in correctly identifying this nematode usually results in its misleading into another species belonging to the same genus. Considering that this pest has almost a worldwide distribution and that it is a virus’s vector, knowledge about it is important to avoid its introduction in new areas, like Brazil.

  7. Detection of two Bartonella tamiae-like sequences in Amblyomma americanum (Acari: Ixodidae) using 16S-23S intergenic spacer region-specific primers.

    Science.gov (United States)

    Billeter, Sarah A; Miller, Melissa K; Breitschwerdt, Edward B; Levy, Michael G

    2008-01-01

    Four hundred and sixty-six questing Amblyomma americanum (L.) (Acari: Ixodidae) from Carolina County, VA, and 98 questing A. americanum from Chatham County, NC, were screened by polymerase chain reaction (PCR) for the Bartonella 16S-23S intergenic spacer region. Two amplicons, approximately 270-280 bp, were detected in two ticks from Virginia. Based upon PCR and sequencing, an adult male and adult female tick harbored DNA sequences closely related to Bartonella tamiae (DQ395180). Bartonella DNA was not detected in A. americanum from North Carolina. Potential transmission of Bartonella spp. by A. americanum should be the focus of future experimental studies.

  8. Site-specific weed control technologies

    DEFF Research Database (Denmark)

    Christensen, S; Søgaard, H T; Kudsk, P

    2009-01-01

    Site-specific weed control technologies are defined as machinery or equipment embedded with technologies that detect weeds growing in a crop and, taking into account predefined factors such as economics, takes action to maximise the chances of successfully controlling them. In the article, we...... describe the basic parts of site specific weed control technologies, comprising of weed sensing systems, weed management models and precision weed control implements. A review of state-of-the-art technologies shows that several weed sensing systems and precision implements have been developed over the last...... two decades, though barriers prevent their breakthrough. Most important among these is the lack of a truly robust weed recognition method, owing to mutual shading among plants and limitations in the capacity of highly accurate spraying and weeding apparatuses.   Another barrier is the lack...

  9. WEED INFESTATION IN DIFFERENT FARMING SYSTEMS

    Directory of Open Access Journals (Sweden)

    MAGDALENA LACKO-BARTOŠOVÁ

    2002-05-01

    Full Text Available The aim of this work was to investigate the influence of ecological and conventional farming systems on weed seedbank and actual weed infestation of winter wheat at agricultural farms Sebechleby, Plavé Vozokany and Dačov Lom. Significant differences between systems were determined only at the co-operative Sebechleby where the higher weed seedbank was in ecological system. Higher number of determined weed species in weed seedstock was in ecological system at Plavé Vozokany and Sebechleby. Dominant weed species in both systems were Chenopodium album L. and Amaranthus retroflexus L.. Higher degree of actual weed infestation was determined in ecological system. Characteristics of systems was the occurrence of perennial species Cirsium arvense and non detection of Amaranthus retroflexus L., weed that had very high weed seedbank in soil.

  10. [Chemical constituents from Solanum rostratum].

    Science.gov (United States)

    Hao, Li-Juan; Wang, Shan; Zhu, Jing-Jing; Wang, Zhi-Min; Wei, Shou-Hui

    2014-06-01

    Ten compounds were isolated from the aerial part of Solanum rostratum by means of various chromatographic techniques such as silica gel, Sephadex LH-20, ODS and preparative HPLC. Their structures were identified as dioscin (1), hypoglaucin H (2), hyperin (3), isoquercitrin (4), isorhamnetin-3-O-beta-D-galactopyranoside (5), kaempferol-3-O-beta-D-glucoside (6), smilaxchinoside A (7), 26-O-beta-D-glucopyranosyl-3beta, 20alpha,26-triol-25 (R) -delta5,22-dienofurostan-3-O-alpha-L-rhamnopyranosyl (1 --> 2) -[ alpha-L-rhamnopyranosyl (1 --> 4)] -beta-D-glucopyranoside (8), beta-sitosterol (9), and daucosterol (10), on the basis of physicochemical properties and spectroscopic data analysis. Among them ,compounds 7 and 8 were isolated from the genus Solanum for the first time, and the remaining compounds were obtained from this plant for the first time.

  11. Detection of Borrelia lonestari in Amblyomma americanum (Acari: Ixodidae) from Tennessee.

    Science.gov (United States)

    Stegall-Faulk, T; Clark, D C; Wright, S M

    2003-01-01

    Genetic sequences characteristic of Borrelia lonestari (Barbour et al. 1996) were detected in two pools of adult Amblyomma americanum (L.) from Tennessee, corresponding to an estimated minimum field infection rate of 8.4 infected ticks/1000 adults. DNA amplification was conducted using primers derived from the B. lonestari flagellin gene that would also amplify Borrelia burgdorferi (Johnson, Schmid, Hyde, Steigerwalt, and Brenner). Species-specific, internal probes were then used to differentiate between genetic sequences of the spirochetes. Subsequent nucleotide sequencing confirmed the presence of B. lonestari in A. americanum; B. burgdorferi was not detected. This represents the first report of B. lonestari from Tennessee, and suggests that Lyme-like illness may occur in Tennessee.

  12. Aspects of Biology and Development of Xiphinema americanum and Related Species.

    Science.gov (United States)

    Halbrendt, J M; Brown, D J

    1993-09-01

    Identification of Xiphinema americanum-group nematodes is based on relatively subtle morphological and morphometric differences, many of which overlap. The significance and importance of these separations cannot be assessed without a basic understanding of the biological differences between species. Currently, information is accumulating on Xiphinema biology, development, and genetics that will help to confirm or refute the current systematics of species in this group. Recently, it was demonstrated that Xiphinema species pass through either three or four juvenile stages before becoming adults. This new and fundamental information divides the genus and the X. americanum group into subgroups based on their developmental evolution and provides new insight into the taxonomy and systematic positions of the species.

  13. Morphometric Evidence for Three Juvenile Stages in Some Species of Xiphinema americanum sensu lato.

    Science.gov (United States)

    Halbrendt, J M; Brown, D J

    1992-06-01

    One to two hundred nematodes from each of seven Xiphinema americanum-group populations were measured to determine the range of stylet and body lengths for juveniles and adults. First-stage juveniles were identified by the position of the replacement odontostyle (i.e., the tip of the replacement odontostyle overlapped the base of the odontophore). Nematodes were identified as second stage if the functional odontostyle was the same length as the replacement odontostyle of the first stage. Subsequent stages were similarly identified by establishing the range of corresponding replacement and functional odontostyle lengths. In all populations examined, this procedure created natural divisions that clearly grouped nematodes by stylet and body length. Presumably these groups identified all juvenile and adult stages. Populations of X. americanum, X. rivesi, and X. californicum from the United States had three juvenile stages, but a population of X. pachtaicum from Bulgaria had four juvenile stages.

  14. IN VITRO CHARACTERIZATION OF NATURAL MUCOADHESIVE AGENT ISOLATED FROM OCIMUM AMERICANUM SEED

    Directory of Open Access Journals (Sweden)

    Avinash B. Gangurde et al

    2012-09-01

    Full Text Available Aim of present investigation was to isolate natural mucoadhesive agent from Ocimum americanum seeds and characterize through in vitro mucoadhesion methods, FTIR and DSC studies. Mucoadhesion force of isolated natural mucoadhesive agents and synthetic polymer Carbopol 934P was determined using in vitro mucoadhesion methods viz. Wihelmy’s method, falling sphere method and modified physical balance method. The research study reveals that the natural mucoadhesive agent isolated from Ocimum americanum seed was shown promising mucoadhesion strength. The formation of hydrogen bond by natural mucoadhesive agent with mucosa was confirmed by FTIR spectra showing carboxyl and hydroxyl groups. Natural mucoadhesive agent may be useful to formulate mucoadhesive drug delivery systems as it bears excellent mucoadhesion property and advantageous over synthetic polymers for less toxicity, biocompatibility, biodegradability and cost.

  15. Weed seed inactivation in soil mesocosms via biosolarization with mature compost and tomato processing waste amendments.

    Science.gov (United States)

    Achmon, Yigal; Fernández-Bayo, Jesús D; Hernandez, Katie; McCurry, Dlinka G; Harrold, Duff R; Su, Joey; Dahlquist-Willard, Ruth M; Stapleton, James J; VanderGheynst, Jean S; Simmons, Christopher W

    2017-05-01

    Biosolarization is a fumigation alternative that combines passive solar heating with amendment-driven soil microbial activity to temporarily create antagonistic soil conditions, such as elevated temperature and acidity, that can inactivate weed seeds and other pest propagules. The aim of this study was to use a mesocosm-based field trial to assess soil heating, pH, volatile fatty acid accumulation and weed seed inactivation during biosolarization. Biosolarization for 8 days using 2% mature green waste compost and 2 or 5% tomato processing residues in the soil resulted in accumulation of volatile fatty acids in the soil, particularly acetic acid, and >95% inactivation of Brassica nigra and Solanum nigrum seeds. Inactivation kinetics data showed that near complete weed seed inactivation in soil was achieved within the first 5 days of biosolarization. This was significantly greater than the inactivation achieved in control soils that were solar heated without amendment or were amended but not solar heated. The composition and concentration of organic matter amendments in soil significantly affected volatile fatty acid accumulation at various soil depths during biosolarization. Combining solar heating with organic matter amendment resulted in accelerated weed seed inactivation compared with either approach alone. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  16. Potential of weed species applied to remediation of soils contaminated with heavy metals

    Institute of Scientific and Technical Information of China (English)

    WEI Shu-He; ZHOU Qi-Xing; WANG Xin; CAO Wei; REN Li-ping; SONG Yu-fang

    2004-01-01

    To screen out a series of ideal plants that can effectively remedy contaminated soils by heavy metals is the main groundwork of phytoremediation engineering and the first step of its commercial application on a large scale. In this study, accumulation and endurance of 45 weed species in 16 families from an agricultural site were in situ examined by using the pot-culture field experiment, and remediation potential of some weed species with high accumulation of heavy metals was assayed. The results showed that Solanum nigrum and Conyza canadensis can not only accumulate high concentration of Cd, but also strongly endure to single Cd and Cd-Pb-Cu-Zn combined pollution. Thus the 2 weed species can be regarded as good hyperaccumulators for the remediation of Cd-contaminated soils. Although there were high Cd-accumulation in Artemigia selengensis, Znula britannica, Artemigia selengensis and Cephalanoplos setosum, their biomass was adversely affected due to action of heavy metals in the soils. If the problem of low endurance to heavy metals can be solved by a reinforcer, the 4 weed species can be perhaps applied commercially.

  17. Can global weed assemblages be used to predict future weeds?

    Directory of Open Access Journals (Sweden)

    Louise Morin

    Full Text Available Predicting which plant taxa are more likely to become weeds in a region presents significant challenges to both researchers and government agencies. Often it is done in a qualitative or semi-quantitative way. In this study, we explored the potential of using the quantitative self-organising map (SOM approach to analyse global weed assemblages and estimate likelihoods of plant taxa becoming weeds before and after they have been moved to a new region. The SOM approach examines plant taxa associations by analysing where a taxon is recorded as a weed and what other taxa are recorded as weeds in those regions. The dataset analysed was extracted from a pre-existing, extensive worldwide database of plant taxa recorded as weeds or other related status and, following reformatting, included 187 regions and 6690 plant taxa. To assess the value of the SOM approach we selected Australia as a case study. We found that the key and most important limitation in using such analytical approach lies with the dataset used. The classification of a taxon as a weed in the literature is not often based on actual data that document the economic, environmental and/or social impact of the taxon, but mostly based on human perceptions that the taxon is troublesome or simply not wanted in a particular situation. The adoption of consistent and objective criteria that incorporate a standardized approach for impact assessment of plant taxa will be necessary to develop a new global database suitable to make predictions regarding weediness using methods like SOM. It may however, be more realistic to opt for a classification system that focuses on the invasive characteristics of plant taxa without any inference to impacts, which to be defined would require some level of research to avoid bias from human perceptions and value systems.

  18. Can Global Weed Assemblages Be Used to Predict Future Weeds?

    Science.gov (United States)

    Morin, Louise; Paini, Dean R.; Randall, Roderick P.

    2013-01-01

    Predicting which plant taxa are more likely to become weeds in a region presents significant challenges to both researchers and government agencies. Often it is done in a qualitative or semi-quantitative way. In this study, we explored the potential of using the quantitative self-organising map (SOM) approach to analyse global weed assemblages and estimate likelihoods of plant taxa becoming weeds before and after they have been moved to a new region. The SOM approach examines plant taxa associations by analysing where a taxon is recorded as a weed and what other taxa are recorded as weeds in those regions. The dataset analysed was extracted from a pre-existing, extensive worldwide database of plant taxa recorded as weeds or other related status and, following reformatting, included 187 regions and 6690 plant taxa. To assess the value of the SOM approach we selected Australia as a case study. We found that the key and most important limitation in using such analytical approach lies with the dataset used. The classification of a taxon as a weed in the literature is not often based on actual data that document the economic, environmental and/or social impact of the taxon, but mostly based on human perceptions that the taxon is troublesome or simply not wanted in a particular situation. The adoption of consistent and objective criteria that incorporate a standardized approach for impact assessment of plant taxa will be necessary to develop a new global database suitable to make predictions regarding weediness using methods like SOM. It may however, be more realistic to opt for a classification system that focuses on the invasive characteristics of plant taxa without any inference to impacts, which to be defined would require some level of research to avoid bias from human perceptions and value systems. PMID:23393591

  19. Characterization of the Bacterial Communities of Life Stages of Free Living Lone Star Ticks (Amblyomma americanum)

    OpenAIRE

    Amanda Jo Williams-Newkirk; Rowe, Lori A.; Mixson-Hayden, Tonya R.; Dasch, Gregory A.

    2014-01-01

    The lone star tick (Amblyomma americanum) is an abundant and aggressive biter of humans, domestic animals, and wildlife in the southeastern-central USA and an important vector of several known and suspected zoonotic bacterial pathogens. However, the biological drivers of bacterial community variation in this tick are still poorly defined. Knowing the community context in which tick-borne bacterial pathogens exist and evolve is required to fully understand the ecology and immunobiology of the ...

  20. Geographic distribution and genetic diversity of the Ehrlichia sp. from Panola Mountain in Amblyomma americanum

    OpenAIRE

    Williamson Phillip C; Garrison Laurel E; Yabsley Michael J; Mixson Tonya R; Stromdahl Ellen Y; Loftis Amanda D; Fitak Robert R; Fuerst Paul A; Kelly Daryl J; Blount Keith W

    2008-01-01

    Abstract Background A novel Ehrlichia, closely related to Ehrlichia ruminantium, was recently discovered from Panola Mountain State Park, GA, USA. We conducted a study to determine if this agent was recently introduced into the United States. Methods We developed a sensitive PCR assay based on the conserved gltA (citrate synthase) gene and tested DNA samples extracted from 1964 field-collected and 1835 human-biting Amblyomma americanum from 23 eastern states of the USA. Results The novel agen...

  1. A revision of the Solanum elaeagnifolium clade (Elaeagnifolium clade; subgenus Leptostemonum, Solanaceae

    Directory of Open Access Journals (Sweden)

    Sandra Knapp

    2017-08-01

    Full Text Available The Solanum elaeagnifolium clade (Elaeagnifolium clade contains five species of small, often rhizomatous, shrubs from deserts and dry forests in North and South America. Members of the clade were previously classified in sections Leprophora, Nycterium and Lathyrocarpum, and were not thought to be closely related. The group is sister to the species-rich monophyletic Old World clade of spiny solanums. The species of the group have an amphitropical distribution, with three species in Mexico and the southwestern United States and three species in Argentina. Solanum elaeagnifolium occurs in both North and South America, and is a noxious invasive weed in dry areas worldwide. Members of the group are highly variable morphologically, and this variability has led to much synonymy, particularly in the widespread S. elaeagnifolium. We here review the taxonomic history, morphology, relationships and ecology of these species and provide keys for their identification, descriptions, full synonymy (including designations of lectotypes and nomenclatural notes. Illustrations, distribution maps and preliminary conservation assessments are provided for all species.

  2. Evaluation of Broadleaf Weeds Control with Selectivity of Post-Emergence Herbicides in Sugar Beet (Beta vulgaris L.)

    OpenAIRE

    Ali Asghar CHITBAND; Ghorbani, Reza; Mohammad Hassan RASHED MOHASSEL; Majid ABBASPOOR; Abbasi, Rahmat

    2014-01-01

    The reduction of herbicide applications is a main research priority in recent years. In order to study the effect of individual post-emergence application of sugar beet broad-leaf herbicides at four to six true-leaf stage of weeds, experiments were conducted during 2013. Treatments included untreated control and several rates of desmedipham + phenmedipham + ethofumesate, chloridazon and clopyralid on Portulaca oleracea, Solanum nigrum, Amaranthus retroflexus and Chenopodium album. A completel...

  3. The Phytogeography of New Guinea Solanum (Solanaceae)

    NARCIS (Netherlands)

    Symon, D.E.

    1986-01-01

    The Solanaceae, of which Solanum is the type species, comprise a southern hemisphere family. A general biogeographical introduction is given, with an account of plate tectonics and a discussion of Wallace’s Line and the geographic history of New Guinea. The widely accepted sections of Solanum are di

  4. Little Pend Oreille - Weeding for Wildlife

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The project builds on previous funding to work with volunteers to manage weeds. Our hope is train volunteers in the use of GPS units, map the extent of specific weed...

  5. Sheldon-Hart - High Desert Weed Management

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — (1)Treat 500 acres of previously mapped invasive weeds on Hart Mountain; followup monitoring and spot treatment where needed, (2)treat 110 acres of invasive weeds...

  6. Characterization of Xiphinema americanum group species (Nematoda: Dorylaimida) and co-evolution of bacteria from the genus ‘Candidatus Xiphinematobacter’ with these nematodes

    Science.gov (United States)

    The Xiphinema americanum group contains over two-dozen different species of nematode. They are economically important because they vector nepoviruses, which cause damage to several crops. Taxonomic differentiation among species of the X. americanum complex is problematic because many of the species ...

  7. The Weeding of a Historical Society Library.

    Science.gov (United States)

    Drake, Cindy Steinhoff

    1992-01-01

    Describes a major deaccessioning (weeding) project begun in 1985 at the library of the Nebraska State Historical Society, including a brief history of the Society and the events leading to the decision to weed. Public controversy over the handling of the project, benefits of the weeding, and new acquisitions policies are also discussed. (MES)

  8. Prospects for site specific weed management

    DEFF Research Database (Denmark)

    Christensen, Svend; Rasmussen, Jesper; Pedersen, Søren Marcus;

    2014-01-01

    Research on Site Specific Weed Management (SSWM) started in the late 80's. Since that moment, considerable research has been conducted on different aspects of SSWM, from fundamental studies on the spatial ecology of weeds to the applied development and testing of new technologies for weed detection...

  9. What's a Weed? Knowledge, Attitude and Behaviour of Park Visitors about Weeds.

    Directory of Open Access Journals (Sweden)

    Michael Ansong

    Full Text Available Weeds are a major threat to biodiversity globally degrading natural areas of high conservation value. But what are our attitudes about weeds and their management including weeds in national parks? Do we know what a weed is? Do we consider weeds a problem? Do we support their management? Are we unintentionally spreading weeds in parks? To answer these questions, we surveyed visitors entering a large popular national park near the city of Brisbane, Australia. Park visitors were knowledgeable about weeds; with >75% correctly defining weeds as 'plants that grow where they are not wanted'. About 10% of the visitors, however, provided their own sophisticated definitions. This capacity to define weeds did not vary with people's age, sex or level of education. We constructed a scale measuring visitors' overall concern about weeds in parks using the responses to ten Likert scale statements. Over 85% of visitors were concerned about weeds with older visitors, hikers, and those who could correctly define weeds more concerned than their counterparts. The majority think visitors unintentionally introduce seeds into parks, with many (63% having found seeds on their own clothing. However, over a third disposed of these seeds in ways that could facilitate weed spread. Therefore, although most visitors were knowledgeable and concerned about weeds, and support their control, there is a clear need for more effective communication regarding the risk of visitors unintentionally dispersing weed seeds in parks.

  10. What's a Weed? Knowledge, Attitude and Behaviour of Park Visitors about Weeds.

    Science.gov (United States)

    Ansong, Michael; Pickering, Catherine

    2015-01-01

    Weeds are a major threat to biodiversity globally degrading natural areas of high conservation value. But what are our attitudes about weeds and their management including weeds in national parks? Do we know what a weed is? Do we consider weeds a problem? Do we support their management? Are we unintentionally spreading weeds in parks? To answer these questions, we surveyed visitors entering a large popular national park near the city of Brisbane, Australia. Park visitors were knowledgeable about weeds; with >75% correctly defining weeds as 'plants that grow where they are not wanted'. About 10% of the visitors, however, provided their own sophisticated definitions. This capacity to define weeds did not vary with people's age, sex or level of education. We constructed a scale measuring visitors' overall concern about weeds in parks using the responses to ten Likert scale statements. Over 85% of visitors were concerned about weeds with older visitors, hikers, and those who could correctly define weeds more concerned than their counterparts. The majority think visitors unintentionally introduce seeds into parks, with many (63%) having found seeds on their own clothing. However, over a third disposed of these seeds in ways that could facilitate weed spread. Therefore, although most visitors were knowledgeable and concerned about weeds, and support their control, there is a clear need for more effective communication regarding the risk of visitors unintentionally dispersing weed seeds in parks.

  11. What’s a Weed? Knowledge, Attitude and Behaviour of Park Visitors about Weeds

    Science.gov (United States)

    Ansong, Michael; Pickering, Catherine

    2015-01-01

    Weeds are a major threat to biodiversity globally degrading natural areas of high conservation value. But what are our attitudes about weeds and their management including weeds in national parks? Do we know what a weed is? Do we consider weeds a problem? Do we support their management? Are we unintentionally spreading weeds in parks? To answer these questions, we surveyed visitors entering a large popular national park near the city of Brisbane, Australia. Park visitors were knowledgeable about weeds; with >75% correctly defining weeds as ‘plants that grow where they are not wanted’. About 10% of the visitors, however, provided their own sophisticated definitions. This capacity to define weeds did not vary with people’s age, sex or level of education. We constructed a scale measuring visitors’ overall concern about weeds in parks using the responses to ten Likert scale statements. Over 85% of visitors were concerned about weeds with older visitors, hikers, and those who could correctly define weeds more concerned than their counterparts. The majority think visitors unintentionally introduce seeds into parks, with many (63%) having found seeds on their own clothing. However, over a third disposed of these seeds in ways that could facilitate weed spread. Therefore, although most visitors were knowledgeable and concerned about weeds, and support their control, there is a clear need for more effective communication regarding the risk of visitors unintentionally dispersing weed seeds in parks. PMID:26252004

  12. Maximum Entropy-Based Ecological Niche Model and Bio-Climatic Determinants of Lone Star Tick (Amblyomma americanum) Niche.

    Science.gov (United States)

    Raghavan, Ram K; Goodin, Douglas G; Hanzlicek, Gregg A; Zolnerowich, Gregory; Dryden, Michael W; Anderson, Gary A; Ganta, Roman R

    2016-03-01

    The potential distribution of Amblyomma americanum ticks in Kansas was modeled using maximum entropy (MaxEnt) approaches based on museum and field-collected species occurrence data. Various bioclimatic variables were used in the model as potentially influential factors affecting the A. americanum niche. Following reduction of dimensionality among predictor variables using principal components analysis, which revealed that the first two principal axes explain over 87% of the variance, the model indicated that suitable conditions for this medically important tick species cover a larger area in Kansas than currently believed. Soil moisture, temperature, and precipitation were highly correlated with the first two principal components and were influential factors in the A. americanum ecological niche. Assuming that the niche estimated in this study covers the occupied distribution, which needs to be further confirmed by systematic surveys, human exposure to this known disease vector may be considerably under-appreciated in the state.

  13. Inter- and Intraspecific Variation in Wild-type and Single Female-derived Populations of Xiphinema americanum-group Nematodes.

    Science.gov (United States)

    Halbrendt, J M; Brown, D J

    1994-06-01

    Ten populations of Xiphinema americanum-group nematodes were reared from individual females to evaluate inter- and intraspecific variation under identical host and environmental conditions. Data indicated that morphometric variability of X. americanum was the result of genetic variation rather than phenotypic plasticity and that genetic heterogeneity was greater than previously thought. Morphometrics of single female derived (SFD) populations identified different genotypes present in the field populations. Stylet length was the least variable morphometric character of SFD populations, but collectively stylet measurements of all individuals formed an uninterrupted continuum ranging from 107-148 mum. Range and frequency of stylet measurements of field populations could be accounted for by the relative proportion of different genotypes in the population. Nine SFD populations were identified as X. americanum sensu stricto, and one SFD population was similar to X. californicum.

  14. A new tetraploid species of Solanum L. sect. Solanum (Solanaceae) from Tanzania

    Science.gov (United States)

    Manoko, Mkabwa L. K.; van Weerden, Gerard M.; van Berg, Ronald G.; Mariani, Celestina

    2012-01-01

    Abstract Solanum umalilaense Manoko sp. nov. (Solanaceae) is described from the Umalila area, in the southern highlands of Tanzania. Its novelty is supported with both morphological and AFLP data. Phenetic and phylogenetic analyses place Solanum umalilaense as a unique and well-supported taxon among tetraploid species of Solanum sect. Solanum from Africa. It can be distinguished from other African species by its extremely developed branching, each branch producing many multi-flowered inflorescences, flowers with short calyx lobes and its persistent, small, light yellowish brown fruits. PMID:23233812

  15. Optimization of foramsulfuron doses for post-emergence weed control in maize (Zea mays L.)

    Energy Technology Data Exchange (ETDEWEB)

    Pannacci, E.

    2016-11-01

    Four field experiments were carried out from 2011 to 2014 in order to evaluate the effects of foramsulfuron, applied at the recommended (60.8 g a.i./ha) and reduced doses (1/3 and 2/3), on the efficacy against several of the most important weeds in maize. For each “year-weed” combination, dose-response curves were applied to estimate the dose of foramsulfuron required to obtain 90% and 95% weed control (ED90 and ED95). Foramsulfuron phytotoxicity on maize and crop yield were assessed. Foramsulfuron at 1/3 of the recommended dose (20.3 g a.i./ha) provided 95% efficacy against redroot pigweed (Amaranthus retroflexus L.), green foxtail (Setaria viridis (L.) Beauv.), wild mustard (Sinapis arvensis L.) and black nightshade (Solanum nigrum L.). Velvetleaf (Abutilon theophrasti Medik.), common lambsquarters (Chenopodium album L.) and barnyardgrass (Echinochloa crus-galli (L.) Beauv.) were satisfactorily controlled (95% weed efficacy) with ED95 ranged from 20 to 50 g/ha of foramsulfuron (about from 1/3 to 5/6 of the recommended dose) depending on growth stage. The recommended dose was effective against pale smartweed (Polygonum lapathifolium L.) at 2-4 true leaves (12-14 BBCH scale), but this dose did not kill plants larger than 2-4 true leaves. The ranking among weed species based on their susceptibility to foramsulfuron was: redroot pigweed = green foxtail = wild mustard = black nightshade > velvetleaf = common lambsquarters = barnyardgrass > pale smartweed. Dose of foramsulfuron can be reduced below recommended dose depending on weed species and growth stage. Foramsulfuron showed a good crop selectivity and had no negative effect on maize yield. (Author)

  16. Optimization of foramsulfuron doses for post-emergence weed control in maize (Zea mays L.

    Directory of Open Access Journals (Sweden)

    Euro Pannacci

    2016-08-01

    Full Text Available Four field experiments were carried out from 2011 to 2014 in order to evaluate the effects of foramsulfuron, applied at the recommended (60.8 g a.i./ha and reduced doses (1/3 and 2/3, on the efficacy against several of the most important weeds in maize. For each “year-weed” combination, dose-response curves were applied to estimate the dose of foramsulfuron required to obtain 90% and 95% weed control (ED90 and ED95. Foramsulfuron phytotoxicity on maize and crop yield were assessed. Foramsulfuron at 1/3 of the recommended dose (20.3 g a.i./ha provided 95% efficacy against redroot pigweed (Amaranthus retroflexus L., green foxtail (Setaria viridis (L. Beauv., wild mustard (Sinapis arvensis L. and black nightshade (Solanum nigrum L.. Velvetleaf (Abutilon theophrasti Medik., common lambsquarters (Chenopodium album L. and barnyardgrass (Echinochloa crus-galli (L. Beauv. were satisfactorily controlled (95% weed efficacy with ED95 ranged from 20 to 50 g/ha of foramsulfuron (about from 1/3 to 5/6 of the recommended dose depending on growth stage. The recommended dose was effective against pale smartweed (Polygonum lapathifolium L. at 2-4 true leaves (12-14 BBCH scale, but this dose did not kill plants larger than 2-4 true leaves. The ranking among weed species based on their susceptibility to foramsulfuron was: redroot pigweed = green foxtail = wild mustard = black nightshade > velvetleaf = common lambsquarters = barnyardgrass > pale smartweed. Dose of foramsulfuron can be reduced below recommended dose depending on weed species and growth stage. Foramsulfuron showed a good crop selectivity and had no negative effect on maize yield.

  17. A newly-discovered Cd-hyperaccumulator Solanum nigrum L.

    Institute of Scientific and Technical Information of China (English)

    WEI Shuhe; ZHOU Qixing; WANG Xin; ZHANG Kaisong; GUO Guanlin; MA Lena Qiying

    2005-01-01

    A systematic investigation was conducted to screen for cadmium-hyperaccumulator from 54 species in 20 weed families using outdoor pot-culture experiment and small-scale field experiment. The results from the outdoor pot-culture experiment showed that Cd concentrations in the stems and leaves of Solanum nigrum L. growing in a soil spiked with 25 mg/kg Cd were up to 103.8 and 124.6 mg/kg (DW), respectively, which was greater than 100 mg/kg, minimum Cd concentration for a Cd-hyperaccumulator. The Cd enrichment factor (EF, concentration ratio in plant to soil) in shoots was as high as 2.68. Moreover, Cd accumulation in shoots was greater than that in roots (TF, concentration ratio in shoots to roots) and the plant biomass growth was not inhibited at the Cd concentrations tested compared with the control. The results of the small-scale field experiment also showed that the characteristics of Cd accumulation in S. nigrum were all consistent with the characteristics of Cd-hyperaccumulators. Thus S. nigrum can be classified as a Cd-hyperaccumulator. This work is important for further research in the areas of hyperaccumulators screening, and plant-tolerance physiology and evolution. It provides a patentable new plant species for phytoremediation of Cd-con- taminated soils.

  18. Efficient Virus-Induced Gene Silencing in Solanum rostratum.

    Directory of Open Access Journals (Sweden)

    Lan-Huan Meng

    Full Text Available Solanum rostratum is a "super weed" that grows fast, is widespread, and produces the toxin solanine, which is harmful to both humans and other animals. To our knowledge, no study has focused on its molecular biology owing to the lack of available transgenic methods and sequence information for S. rostratum. Virus-induced gene silencing (VIGS is a powerful tool for the study of gene function in plants; therefore, in the present study, we aimed to establish tobacco rattle virus (TRV-derived VIGS in S. rostratum. The genes for phytoene desaturase (PDS and Chlorophyll H subunit (ChlH of magnesium protoporphyrin chelatase were cloned from S. rostratum and used as reporters of gene silencing. It was shown that high-efficiency VIGS can be achieved in the leaves, flowers, and fruit of S. rostratum. Moreover, based on our comparison of three different types of infection methods, true leaf infection was found to be more efficient than cotyledon and sprout infiltration in long-term VIGS in multiple plant organs. In conclusion, the VIGS technology and tomato genomic sequences can be used in the future to study gene function in S. rostratum.

  19. Efficient Virus-Induced Gene Silencing in Solanum rostratum.

    Science.gov (United States)

    Meng, Lan-Huan; Wang, Rui-Heng; Zhu, Ben-Zhong; Zhu, Hong-Liang; Luo, Yun-Bo; Fu, Da-Qi

    2016-01-01

    Solanum rostratum is a "super weed" that grows fast, is widespread, and produces the toxin solanine, which is harmful to both humans and other animals. To our knowledge, no study has focused on its molecular biology owing to the lack of available transgenic methods and sequence information for S. rostratum. Virus-induced gene silencing (VIGS) is a powerful tool for the study of gene function in plants; therefore, in the present study, we aimed to establish tobacco rattle virus (TRV)-derived VIGS in S. rostratum. The genes for phytoene desaturase (PDS) and Chlorophyll H subunit (ChlH) of magnesium protoporphyrin chelatase were cloned from S. rostratum and used as reporters of gene silencing. It was shown that high-efficiency VIGS can be achieved in the leaves, flowers, and fruit of S. rostratum. Moreover, based on our comparison of three different types of infection methods, true leaf infection was found to be more efficient than cotyledon and sprout infiltration in long-term VIGS in multiple plant organs. In conclusion, the VIGS technology and tomato genomic sequences can be used in the future to study gene function in S. rostratum.

  20. Weed suppression ability of spring barley varieties

    DEFF Research Database (Denmark)

    Christensen, Svend

    1995-01-01

    Three years of experiments with spring barley showed significant differences in weed suppression ability among varieties. Weed dry matter in the most suppressive variety, Ida, was 48% lower than the mean weed dry matter of all varieties, whereas it was 31% higher in the least suppressive variety......, Grit. Ranking varietal responses to weed competition in terms of grain yield loss corresponded well to ranking weed dry matter produced in crop weed mixtures. There was no correspondence between the varietal grain yields in pure stands and their competitiveness, suggesting that breeding to optimize...... interception model was developed to describe the light interception profiles of the varieties. A study of the estimated parameters showed significant correlation between weed dry matter, rate of canopy height development and the light interception profile. However, when estimates were standardized to eliminate...

  1. Weed biocontrol in landscape restoration

    Science.gov (United States)

    Weed biological control programs in natural areas are often undertaken with the goal of restoring native plant communities and/or ecosystem services to a pre-invasion level. These objectives may be achieved in some areas with biological control alone; however, in other sites integration of biologica...

  2. Rounding Up the Astrophysical Weeds

    Science.gov (United States)

    McMillan, James P.

    2016-09-01

    New instruments used for astronomy such as ALMA, Herschel, and SOFIA have greatly increased the quality of available astrophysical data. These improved data contain spectral lines and features which are not accounted for in the quantum mechanical (QM) catalogs. A class of molecules has been identified as being particularly problematic, the so-called "weeds". These molecules have numerous transitions, of non-trivial intensity, which are difficult to model due to highly perturbed low lying vibrational states. The inability to properly describe the complete contribution of these weeds to the astrophysical data has led directly to the misidentification of other target molecules. Ohio State's Microwave Laboratory has developed an alternative approach to this problem. Rather than relying on complex QM calculations, we have developed a temperature dependent approach to laboratory based terahertz spectroscopy. We have developed a set of simple packages, in addition to traditional line list catalogs, that enable astronomers to successfully remove the weed signals from their data. This dissertation will detail my laboratory work and analysis of three keys weeds: methanol, methyl formate and methyl cyanide. Also, discussed will be the analytical technique I used to apply these laboratory results to astrophysical data.

  3. The Microbiome of Ehrlichia-Infected and Uninfected Lone Star Ticks (Amblyomma americanum)

    Science.gov (United States)

    Trout Fryxell, R. T.; DeBruyn, J. M.

    2016-01-01

    The Lone Star tick, Amblyomma americanum, transmits several bacterial pathogens including species of Anaplasma and Ehrlichia. Amblyomma americanum also hosts a number of non-pathogenic bacterial endosymbionts. Recent studies of other arthropod and insect vectors have documented that commensal microflora can influence transmission of vector-borne pathogens; however, little is known about tick microbiomes and their possible influence on tick-borne diseases. Our objective was to compare bacterial communities associated with A. americanum, comparing Anaplasma/Ehrlichia -infected and uninfected ticks. Field-collected questing specimens (n = 50) were used in the analyses, of which 17 were identified as Anaplasma/Ehrlichia infected based on PCR amplification and sequencing of groEL genes. Bacterial communities from each specimen were characterized using Illumina sequencing of 16S rRNA gene amplicon libraries. There was a broad range in diversity between samples, with inverse Simpson’s Diversity indices ranging from 1.28–89.5. There were no statistical differences in the overall microbial community structure between PCR diagnosed Anaplasma/Ehrlichia-positive and negative ticks, but there were differences based on collection method (P Anaplasma. Other taxa of interest in these specimens included Coxiella, Borrelia, and Rickettsia. Identification of bacterial community differences between specimens of a single tick species from a single geographical site indicates that intra-species differences in microbiomes were not due solely to pathogen presence/absence, but may be also driven by vector life history factors, including environment, life stage, population structure, and host choice. PMID:26751816

  4. Bacterial diversity in Amblyomma americanum (Acari: Ixodidae) with a focus on members of the genus Rickettsia.

    Science.gov (United States)

    Heise, Stephanie R; Elshahed, M S; Little, S E

    2010-03-01

    The lone star tick, Amblyomma americanum (Acari: Ixodidae), is commonly reported from people and animals throughout the eastern U.S. and is associated with transmission of a number of emerging diseases. To better define the microbial communities within lone star ticks, 16S rRNA gene based analysis using bacteria-wide primers, followed by sequencing of individual clones (n = 449) was used to identify the most common bacterial operational taxonomic units (OTUs) present within colony-reared and wild A. americanum. The colony-reared ticks contained primarily sequence affiliated with members of the genus Coxiella (89%; 81/91), common endosymbionts of ticks, and Brevibacterium (11%; 10/91). Similarly, analysis of clones from unfed wild lone star ticks revealed that 96.7% (89/92) of all the OTUs identified were affiliated with Coxiella-like endosymbionts, as compared with only 5.1-11.7% (5/98-9/77) of those identified from wild lone star ticks after feeding. In contrast, the proportion of OTUs identified as Rickettsia sp. in wild-caught ticks increased from 2.2% (2/92) before feeding to as high as 46.8% (36/77) after feeding, and all Rickettsia spp. sequences recovered were most similar to those described from the spotted fever group Rickettsia, specifically R. amblyommii and R. massiliae. Additional characterization of the Rickettsiales tick community by polymerase chain reaction, cloning, and sequencing of 17 kDa and gltA genes confirmed these initial findings and suggested that novel Rickettsia spp. are likely present in these ticks. These data provide insight into the overall, as well as the rickettsial community of wild lone star ticks and may ultimately aid in identification of novel pathogens transmitted by A. americanum.

  5. Antibiotic treatment of the tick vector Amblyomma americanum reduced reproductive fitness.

    Directory of Open Access Journals (Sweden)

    Jianmin Zhong

    Full Text Available BACKGROUND: The lone star tick Amblyomma americanum is a common pest and vector of infectious diseases for humans and other mammals in the southern and eastern United States. A Coxiella sp. bacterial endosymbiont was highly prevalent in both laboratory-reared and field-collected A. americanum. The Coxiella sp. was demonstrated in all stages of tick and in greatest densities in nymphs and adult females, while a Rickettsia sp. was less prevalent and in lower densities when present. METHODOLOGY/PRINCIPAL FINDINGS: We manipulated the numbers of both bacterial species in laboratory-reared A. americanum by injecting engorged nymphs or engorged, mated females with single doses of an antibiotic (rifampin or tetracycline or buffer alone. Burdens of the bacteria after molting or after oviposition were estimated by quantitative polymerase chain reaction with primers and probes specific for each bacterial species or, as an internal standard, the host tick. Post-molt adult ticks that had been treated with rifampin or tetracycline had lower numbers of the Coxiella sp. and Rickettsia sp. and generally weighed less than ticks that received buffer alone. Similarly, after oviposition, females treated previously with either antibiotic had lower burdens of both bacterial species in comparison to controls. Treatment of engorged females with either antibiotic was associated with prolonged time to oviposition, lower proportions of ticks that hatched, lower proportions of viable larvae among total larvae, and lower numbers of viable larvae per tick. These fitness estimators were associated with reduced numbers of the Coxiella sp. but not the Rickettsia sp. CONCLUSION/SIGNIFICANCE: The findings indicate that the Coxiella sp. is a primary endosymbiont, perhaps provisioning the obligately hematophagous parasites with essential nutrients. The results also suggest that antibiotics could be incorporated into an integrated pest management plan for control of these and other

  6. Transmission of Tomato Ringspot Virus by Xiphinema americanum and X. rivesi from New York Apple Orchards.

    Science.gov (United States)

    Georgi, L L

    1988-04-01

    Populations of Xiphinema americanum and X. rivesi were collected from apple orchards in eastern and western New York and tested in the laboratory for ability to transmit tomato ringspot virus (TmRSV) to cucumber and dandelion. Populations varied in the frequency with which they transmitted TmRSV, but this variation did not correspond to variation in disease prevalence in the orchard. The lower prevalence of TmRSV-incited disease in apple trees in western New York cannot be attributed to inability of the local Xiphinema spp. to transmit TmRSV.

  7. The Microbiome of Ehrlichia-Infected and Uninfected Lone Star Ticks (Amblyomma americanum.

    Directory of Open Access Journals (Sweden)

    R T Trout Fryxell

    Full Text Available The Lone Star tick, Amblyomma americanum, transmits several bacterial pathogens including species of Anaplasma and Ehrlichia. Amblyomma americanum also hosts a number of non-pathogenic bacterial endosymbionts. Recent studies of other arthropod and insect vectors have documented that commensal microflora can influence transmission of vector-borne pathogens; however, little is known about tick microbiomes and their possible influence on tick-borne diseases. Our objective was to compare bacterial communities associated with A. americanum, comparing Anaplasma/Ehrlichia -infected and uninfected ticks. Field-collected questing specimens (n = 50 were used in the analyses, of which 17 were identified as Anaplasma/Ehrlichia infected based on PCR amplification and sequencing of groEL genes. Bacterial communities from each specimen were characterized using Illumina sequencing of 16S rRNA gene amplicon libraries. There was a broad range in diversity between samples, with inverse Simpson's Diversity indices ranging from 1.28-89.5. There were no statistical differences in the overall microbial community structure between PCR diagnosed Anaplasma/Ehrlichia-positive and negative ticks, but there were differences based on collection method (P < 0.05, collection site (P < 0.05, and sex (P < 0.1 suggesting that environmental factors may structure A. americanum microbiomes. Interestingly, there was not always agreement between Illumina sequencing and PCR diagnostics: Ehrlichia was identified in 16S rRNA gene libraries from three PCR-negative specimens; conversely, Ehrlichia was not found in libraries of six PCR-positive ticks. Illumina sequencing also helped identify co-infections, for example, one specimen had both Ehrlichia and Anaplasma. Other taxa of interest in these specimens included Coxiella, Borrelia, and Rickettsia. Identification of bacterial community differences between specimens of a single tick species from a single geographical site indicates that

  8. The future for weed control and technology.

    Science.gov (United States)

    Shaner, Dale L; Beckie, Hugh J

    2014-09-01

    This review is both a retrospective (what have we missed?) and prospective (where are we going?) examination of weed control and technology, particularly as it applies to herbicide-resistant weed management (RWM). Major obstacles to RWM are discussed, including lack of diversity in weed management, unwillingness of many weed researchers to conduct real integrated weed management research or growers to accept recommendations, influence or role of agrichemical marketing and governmental policy and lack of multidisciplinary research. We then look ahead to new technologies that are needed for future weed control in general and RWM in particular, in areas such as non-chemical and chemical weed management, novel herbicides, site-specific weed management, drones for monitoring large areas, wider application of 'omics' and simulation model development. Finally, we discuss implementation strategies for integrated weed management to achieve RWM, development of RWM for developing countries, a new classification of herbicides based on mode of metabolism to facilitate greater stewardship and greater global exchange of information to focus efforts on areas that maximize progress in weed control and RWM. There is little doubt that new or emerging technologies will provide novel tools for RMW in the future, but will they arrive in time? © 2013 Her Majesty the Queen in Right of Canada Pest Management Science © 2013 Society of Chemical Industry.

  9. Comparative assessment for hyperaccumulatory and phytoremediation capability of three wild weeds.

    Science.gov (United States)

    Girdhar, Madhuri; Sharma, Neeta Raj; Rehman, Hasibur; Kumar, Anupam; Mohan, Anand

    2014-12-01

    The composition and the organization of soil are changing rapidly by the diverged mankind activities, leading to the contamination of environment. Several methods are employed to clean up the environment from these kinds of contaminants, but most of them are costly and ineffective to yield optimum results. Phytoremediation is a natural green technology, which is eco-friendly for the removal of toxic metals from the polluted environment. Phytoremediation is a cost-effective technique through which the cleanup of contaminated soil laced with heavy metals is performed by wild weeds and small herbal plants. The phytoremediation technique provides a promising tool for hyperaccumulation of heavy metals; arsenic, lead, mercury, copper, chromium, and nickel, etc., by the wild weeds and that has been discussed here in detail in case of Cannabissativa, Solanum nigrum and Rorippa globosa. In general, weeds that have the intrinsic capacity to accumulate metals into their shoots and roots, have the ability to form phytochelates and formation of stable compound with ions. This behavior of accumulation along with chelate and stable compound formation is utilized as a tool for phytoremediation activity.

  10. A new tetraploid species of Solanum section Solanum (Solanaceae) from Tanzania

    NARCIS (Netherlands)

    Manoko, M.L.K.; Weerden, van der G.M.; Berg, van den R.G.; Mariani, C.

    2012-01-01

    Solanum umalilaense Manoko sp. nov. (Solanaceae) is described from the Umalila area, in the southern highlands of Tanzania. Its novelty is supported with both morphological and AFLP data. Phenetic and phylogenetic analyses place Solanum umalilaense as a unique and well-supported taxon among tetraplo

  11. A Review on Reasons of Increasing Perennial Weeds and Control Technology of Perennial Weeds in Heilongjiang Province

    Institute of Scientific and Technical Information of China (English)

    ZHAO Changshan; HE Fuli; SHI Na; YAN Chunxiu

    2009-01-01

    The main reasons that perennial weeds has becoming the dominant weeds in Heilongjiang Province were summarized.The biological mechanism that explained why it was difficult to control perennial weeds was analyzed. During dormancy course,variation regularity of some inner matters in perennial weeds was researched and new tentative for controlling the perennial weeds was pointed out.

  12. Ehrlichia chaffeensis (Rickettsiales: Ehrlichieae) infection in Amblyomma americanum (Acari: Ixodidae) at Aberdeen Proving Ground, Maryland.

    Science.gov (United States)

    Stromdahl, E Y; Randolph, M P; O'Brien, J J; Gutierrez, A G

    2000-05-01

    Human monocytic ehrlichiosis (HME) is a sometimes fatal, emerging tick-borne disease caused by the bacterium Ehrlichia chaffeensis. It is frequently misdiagnosed because its symptoms mimic those of the flu. Current evidence indicates that Amblyomma americanum (L.), the lone star tick, is the major vector of HME. To determine if E. chaffeensis is present in ticks at Aberdeen Proving Ground, MD, questing A. americanum ticks were collected from 33 sites. Nucleic acid was extracted from 34 adult and 81 nymphal pools. Sequences diagnostic for E. chaffeensis from three different loci (16S rRNA, 120-kDa protein, and a variable-length polymerase chain reaction [PCR] target, or VLPT) were targeted for amplification by the PCR. Fifty-two percent of the collection sites yielded pools infected with E. chaffeensis, confirming the presence and widespread distribution of E. chaffeensis at Aberdeen Proving Ground. Analysis with the both the 120-kDa protein primers and the VLPT primers showed that genetic variance exists. A novel combination of variance for the two loci was detected in two tick pools. The pathogenic implications of genetic variation in E. chaffeensis are as yet unknown.

  13. Inferring the population structure and demographic history of the tick, Amblyomma americanum Linnaeus.

    Science.gov (United States)

    Mixson, Tonya R; Lydy, Shari L; Dasch, Gregory A; Real, Leslie A

    2006-06-01

    A hierarchial population genetic study was conducted on 703 individual Amblyomma americanum from nine populations in Georgia, U.S.A. Populations were sampled from the Coastal Plain, midland Piedmont region, and the upper Piedmont region. Twenty-nine distinct haplotypes were found. A minimum spanning tree was constructed that indicated these haplotypes comprised two lineages, the root of which was distinctly star-like. The majority of the variation found was among ticks within each population, indicating high amounts of gene flow and little genetic differentiation between the three regions. An overall F(ST) value of 0.006 supported the lack of genetic structuring between collection sites in Georgia. Mantel regression analysis revealed no isolation by distance. Signatures of population expansion were detected in the shapes of the mismatch distribution and tests of neutrality. The absence of genetic differentiation combined with the rejection of the null model of isolation by distance may indicate recent range expansion in Georgia or insufficient time to reach an equilibrium where genetic drift may have affected allele frequencies. Alternatively, the high degree of panmixia found within A. americanum in Georgia may be due to bird-mediated dispersal of ticks increasing the genetic similarity between geographically separated populations.

  14. In vitro membrane feeding of the lone star tick (Amblyomma americanum) and its use in evaluation of acaricidal compounds

    Science.gov (United States)

    The lone star tick, Amblyomma americanum, is one of important Ixodid tick species that are known ectoparasites and disease vectors affecting animal and human health in the United States. New pesticides or repellents with novel mode of action would help control resistant ticks and protect humans from...

  15. The chemosensory appendage proteome of Amblyomma americanum (Acari: Ixodidae) reveals putative odorant-binding and other chemoreception-related proteins

    Science.gov (United States)

    Proteomic analyses were done on 2 chemosensory appendages of the lone star tick, Amblyomma americanum. Proteins in the fore tarsi, which contain the olfactory Haller's organ, and in the palps, that include gustatory sensilla, were compared with proteins in the third tarsi. Also, male and female tick...

  16. Elemol and amyris oil repel the ticks Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae) in laboratory bioassays.

    Science.gov (United States)

    Carroll, J F; Paluch, G; Coats, J; Kramer, M

    2010-08-01

    The essential oil from Amyris balsamifera (Rutaceae) and elemol, a principal constituent of the essential oil of Osage orange, Maclura pomifera (Moraceae) were evaluated in in vitro and in vivo laboratory bioassays for repellent activity against host-seeking nymphs of the blacklegged tick, Ixodes scapularis, and the lone star tick, Amblyomma americanum. Both bioassays took advantage of the tendency of these host-seeking ticks to climb slender vertical surfaces. In one bioassay, the central portion of a vertical strip of filter paper was treated with test solution and ticks placed or allowed to crawl onto the untreated lower portion. In the other bioassay, a strip of organdy cloth treated with test solution was doubly wrapped (treatment on outer layer) around the middle phalanx of a forefinger and ticks released on the fingertip. Both amyris oil and elemol were repellent to both species of ticks. Elemol did not differ significantly in effectiveness against A. americanum from the widely used repellent deet. At 2 and 4 h after application to filter paper, 827 microg amyris oil/cm(2) paper repelled 80 and 55%, respectively, of A. americanum nymphs. Ixodes scapularis was repelled by lower concentrations of amyris oil and elemol than A. americanum.

  17. Epianthropochory in Mexican weed communities.

    Science.gov (United States)

    Vibrans, H

    1999-04-01

    The diaspores of the 50 most important maize field weed species (agrestals) in a traditional maize-growing area of south-central Mexico (region of Puebla and Tlaxcala) were analyzed for morphological adaptations to long-distance dispersal. Adaptations to wind-dispersal were absent and to endozoochory were minimal. Most species had no visible adaptations and are presumably transported with mud. However, about one-quarter of the taxa, particularly the tall and dominant ones, relied at least partially on burrs with hooks or awns. The possible vectors for these exo- or epizoochorous species are discussed: the most likely regular dispersers are humans (epianthropochory). Interviews with farmers confirm this conclusion. Using humans as vectors allows the plant to transport relatively large seeds to favorable habitats (directed dispersal). The importance of this relatively rare dispersal adaptation in Mexican maize field weeds leads to questions on the origin and evolution of these agrestals.

  18. Precise tillage systems for enhanced non-chemical weed management

    NARCIS (Netherlands)

    Kurstjens, D.A.G.

    2007-01-01

    Soil and residue manipulation can assist weed management by killing weeds mechanically, interfering in weed lifecycles, facilitating operations and enhancing crop establishment and growth. Current tillage systems often compromise these functions, resulting in heavy reliance on herbicides,

  19. Chapter Three - Weed Dynamics and Management in Wheat

    DEFF Research Database (Denmark)

    Jabran, Khawar; Mahmood, Khalid; Melander, Bo

    2017-01-01

    pest of wheat causing in total 24% losses in wheat grain yield. In this chapter, we discuss the (i) weed flora in different wheat-growing regions of world; (ii) the yield losses caused by weeds in wheat; (iii) the preventive and cultural options for weed management; (iv) physical weed control; (v......) chemical weed control; and (vi) integrated weed management strategy in wheat. A critical analysis of recent literature indicated that broadleaved weeds are the most common group of weeds in wheat fields followed by grass weeds, while sedges were rarely noted in wheat fields. Across the globe, the most...... important weeds in wheat fields were Avena fatua L., Chenopodium album L., Phalaris minor Retz., Galium aparine L., Stellaria media (L.) Vill., and Veronica persica Poir., respectively. Adoption of wise weed management strategies may help control weeds and avoid yield losses. Both preventive measures...

  20. Reproduction of Pratylenchus zeae on Weeds

    OpenAIRE

    BELLÉ,C.; KASPARY, T. E.; KUHN,P.R.; Schmitt, J.; LIMA-MEDINA, I.

    2017-01-01

    ABSTRACT Weeds can be hosts of root-lesion nematode (Pratylenchus spp.), maintaining or increasing their population in the soil. The objective of this study was to evaluate the reaction of 25 weeds species to the nematode Pratylenchus zeae. The weed plants were individually inoculated with 1,000 individuals of P. zeae and maintained in a greenhouse for 90 days. After this period, eggs and nematodes were extracted, quantified, and the reproduction factor (RF = final population/initial populati...

  1. Weeding Is Not Just for Gardeners: A Case Study on Weeding a Reference Collection

    Science.gov (United States)

    Lee, Marta

    2009-01-01

    Weeding a reference collection can be time consuming, a thankless job, and an endless task. It is a dusty job and can add to the librarian's workload. Weeding the collection can add to its currency and usability; plus it removes outdated materials. Periodically weeding allows librarians to remember what is in the collection and what can be removed…

  2. Linking Farmer Weed Management Behavior with Weed Pressure: More than Just Technology

    NARCIS (Netherlands)

    Riemens, M.M.; Groeneveld, R.M.W.; Kropff, M.J.; Lotz, L.A.P.; Renes, R.J.; Sukkel, W.; Weide, van der R.Y.

    2010-01-01

    Most studies on weed population dynamics in farming systems have focused on the effects of different weed control strategies. Those studies usually assume that farmers, operating within a particular system, have a uniform management style. However, it is likely that weed management decision making

  3. About the value of species diversity in arable weeds for weed management

    Directory of Open Access Journals (Sweden)

    Gerowitt, Bärbel

    2016-02-01

    Full Text Available Arable weeds accompany arable land use – we define them based on their affiliation to ar able systems. They are adapted to such a degree that most of them cannot exist without arable land use. Weeds are part of the total biodiversity on arable fields, as primary producers they are basic for important functions within the ecosystem. This paper elaborates the relevance of species diversity in arable weeds for their management. Arable systems can be regarded for the number of different methods for preventive and direct weed control which are realized. Historical arable land use is roughly divided into three periods, which differ concerning the diversity of weed management and the occurring diversity in weed species. Obviously divers weed management in arable systems and diversity in weed species depend on each other, this is illustrated with a simple abstract picture. Arable systems, which are characterised by simpleness, favor the domination of few species which ensure an effective use of the resources within the ecosystem. One consequence under continuous pressure of an overused tool in weed management is that the genetic diversity within a dominating weed population is exploited to ensure this resource use. Current herbicides represent this tool – the results are herbicide resistant biotypes within the weed populations. Species diversity in arable weeds as a rationale within arable production can assist to prevent this development.

  4. Combining a weed traits database with a population dynamics model predicts shifts in weed communities

    NARCIS (Netherlands)

    Storkey, J.; Holst, N.; Bøjer, Q.; Bigongiali, F.; Bocci, G.; Colbach, N.; Dorner, Z.; Riemens, M.M.; Sartorato, I.; Sønderskov, M.; Verschwele, A.

    2015-01-01

    A functional approach to predicting shifts in weed floras in response to management or environmental change requires the combination of data on weed traits with analytical frameworks that capture the filtering effect of selection pressures on traits. A weed traits database (WTDB) was designed, popul

  5. Integration of herbicides with manual weeding for controlling the weeds in rice under saline environment.

    Science.gov (United States)

    Hakim, M A; Juraimi, Abdul Shukor; Hanafi, M M; Rafii, Mohd Y; Ismail, Mohd Razi; Karim, S M Rezaul; Kausar, H

    2015-11-01

    The pot experiment was conducted to select appropriate integrated weed management method in rice under different salinity levels (0, 4 and 8 dS m(-1)). All the parameters including rice and weed measured were significantly influenced by weed control treatments at all salinity levels. Treatments including weed-free condition, Pretilachlor @0.375 kg ai ha(-1) + hand weeding, Propanil + Thiobencarb @ 0.9 kg ai ha(-1) and 1.8 kg ai ha(-1)+ hand weeding performed better under all salinity levels. Pretilachlor @ 0.375 kg ai ha(-1) with one round of hand weeding and propanil + thiobencarb 0.9 kg ai ha(-1) + 1.8 kg ai ha(-1) with one round of hand weeding were comparable to weed-free yields, and were superior to other treatments under salinity condition. Considering all the parameters, pretilachlor @ 0.375 kg ai ha(-1) + one round of hand weeding (at 65 DAT), propanil + thiobencarb 0.9 kg ai ha(-1) +1.8 kg ai ha(-1) + one round of hand weeding (at 65 DAT) gave the most effective control of weeds in rice under saline environments.

  6. Effect of stale seedbed preparations and subsequent weed control in lettuce (cv. Iceboll) on weed densities

    NARCIS (Netherlands)

    Riemens, M.M.; Weide, van der R.Y.; Bleeker, P.O.; Lotz, L.A.P.

    2007-01-01

    The effects of stale seedbed preparations and several weed control methods on the emergence of weeds in lettuce were studied. The specific goal was to evaluate the use of a stale seedbed in combination with chemical or mechanical weed control methods in the field. Depending on location and year,

  7. Effect of stale seedbed preparations and subsequent weed control in lettuce (cv. Iceboll) on weed densities

    NARCIS (Netherlands)

    Riemens, M.M.; Weide, van der R.Y.; Bleeker, P.O.; Lotz, L.A.P.

    2007-01-01

    The effects of stale seedbed preparations and several weed control methods on the emergence of weeds in lettuce were studied. The specific goal was to evaluate the use of a stale seedbed in combination with chemical or mechanical weed control methods in the field. Depending on location and year, sta

  8. Critical Period of Weed Control in Aerobic Rice

    OpenAIRE

    Anwar, M. P.; A. S. Juraimi; Samedani, B.; Puteh, A.; Man, A.

    2012-01-01

    Critical period of weed control is the foundation of integrated weed management and, hence, can be considered the first step to design weed control strategy. To determine critical period of weed control of aerobic rice, field trials were conducted during 2010/2011 at Universiti Putra Malaysia. A quantitative series of treatments comprising two components, (a) increasing duration of weed interference and (b) increasing length of weed-free period, were imposed. Critical period was determined th...

  9. Nutrient absorbtion of weeds in maize.

    Science.gov (United States)

    Lehoczky, E; Kismányoky, A; Nagy, P; Németh, T

    2008-01-01

    Our study was carried out in Hungary at Keszthely, in 2007. The effect of different cultivation methods: no-till drill, disk tillage, conventional tillage (ploughing) and five increasing N doses were studied on the weediness. The bi-factorial trial was arranged in split plot design with four replications. Crop rotation: winter wheat-winter wheat-maize-maize. The seeding of maize was 23rd of April in 2007. The weed survey was made with Balázs-Ujvárosi coenological method on the 17th of May. In the experiment were found 21 weed species. We collected all plants of every weed species by plots. The sample area was 1 m2. Furthermore five maize plants per plot were sampled on the 22nd of May. Maize was at 3-4 leaves stage. For reason of competition studies no herbicides were applied on sampling sites. The aerial parts of weeds and maize plants were collected, and the fresh and dry matter weight was measured. We analyzed in detail, the occurrence of weed species, and the biomass production of weeds in comparison with maize. The effect of different cultivation methods markedly demonstrated the weed cover, the number of perennial and annual weeds and the number of occurring weed species.

  10. A STUDY ON WEED CONTROL IN SOYBEAN

    Directory of Open Access Journals (Sweden)

    S. TJITROSEMITO

    1991-01-01

    Full Text Available Two field experiments on weed control in soybeans were carried out at BIOTROP, Bogor, Indonesia from February to June, 1989. The critical period for weed control was found to be between 20 - 40 days after planting of soybean (c. v. Wilis grown at a planting distance of 40 x 10 cm. It did not coincide with the fastest growth in terms of trifoliate leaf number. Further studies were suggested to understand the physiological growth of soybean related to weed control. Pendimethalin at 660- 1320 g a.e./ha applied one day after sowing did not cause any phytotoxic effect to soybean and had good weed control performance.

  11. Parthenium Weed (Parthenium hysterophorusL.)

    African Journals Online (AJOL)

    plant compounds (parthenin, chlorogenic acid, isocholorogenic acid, vanilic ... Parthenium Weed (Parthenium hysterophorus L.) Research in Ethiopia ..... other infested areas in Austaralia and America was conducted using cluster analysis.

  12. Weed detection in 3D images

    OpenAIRE

    Piron, Alexis; Van der heijden, F.; Destain, Marie-France

    2011-01-01

    Machine vision has been successfully used for mechanical destruction of weeds between rows of crops. Knowledge of the position of the rows where crops should be growing and the assumption that plants growing outside such positions are weeds may be used in such systems. However for many horticultural crops, the automatic removal of weeds from inside a row or bands of crops in which the weeds are mixed with plants in a random manner is not solved. The aim of this study was to verify that plant ...

  13. Comparison of differentially expressed genes in the salivary glands of male ticks, Amblyomma americanum and Dermacentor andersoni.

    Science.gov (United States)

    Bior, Abdelaziz D; Essenberg, Richard C; Sauer, John R

    2002-06-01

    Genes expressed differentially in the salivary glands of unfed and fed male ticks, Amblyomma americanum (L.), were identified, cloned and sequenced, and some were compared with those expressed in the salivary glands of Dermacentor andersoni. Total protein and RNA increased sixfold in the salivary glands of fed male A. americanum, while in fed male D. andersoni salivary glands, RNA increased approximately 3.5 times. Feeding D. andersoni in the presence of females increased total RNA by 25% over those fed in the absence of females. Complementary DNAs were synthesized from RNA obtained from unfed and fed ticks and amplified using RNA arbitrarily primed polymerase chain reaction (RAP-PCR) with three different primers in separate reactions. Differential display showed clear banding differences between the fed and the unfed ticks in A. americanum and D. andersoni. Sixty-one cDNA fragments that appeared to be from differentially expressed genes in A. americanum were isolated, cloned and sequenced. Hybridization reactions with labeled cDNA probes confirmed the differential expression of many of the genes in unfed and fed ticks' salivary glands; however, many of the bands contained more than one fragment and some of the fragments isolated from apparently differential bands were not specific. Sequences for 28 of the cDNA fragments (150-600 nucleotides in length) demonstrated similarity to genes in the databases, but nine of these were similar to sequences of unknown function. Some of the gene fragments identified may be important to tick feeding or tick salivary gland physiology, including a histamine-binding protein, an organic ion transporter, an apoptosis inhibitor, a cathepsin-B-like cysteine protease, proteins involved in gene regulation and several proteins involved in protein synthesis. Cross-hybridization of identified cDNAs from A. americanum with cDNA probes synthesized from D. andersoni total RNA did not show significant similarity between the two species.

  14. Using mitogenomic and nuclear ribosomal sequence data to investigate the phylogeny of the Xiphinema americanum species complex.

    Directory of Open Access Journals (Sweden)

    Inga A Zasada

    Full Text Available Nematodes within the Xiphinema americanum species complex are economically important because they vector nepoviruses which cause considerable damage to a variety of agricultural crops. The taxonomy of X. americanum species complex is controversial, with the number of putative species being the subject of debate. Accurate phylogenetic knowledge of this group is highly desirable as it may ultimately reveal genetic differences between species. For this study, nematodes belonging to the X. americanum species complex, including potentially mixed species populations, were collected from 12 geographically disparate locations across the U.S. from different crops and in varying association with nepoviruses. At least four individuals from each population were analyzed. A portion of the 18S nuclear ribosomal DNA (rDNA gene was sequenced for all individuals while the internal transcribed spacer region 1 (ITS1 of rDNA was cloned and 2 to 6 clones per individual were sequenced. Mitochondrial genomes for numerous individuals were sequenced in parallel using high-throughput DNA sequencing (HTS technology. Phylogenetic analysis of the 18S rDNA revealed virtually identical sequences across all populations. Analysis of ITS1 rDNA sequences revealed several well-supported clades, with some degree of congruence with geographic location and viral transmission, but also numerous presumably paralogous sequences that failed to form clades with other sequences from the same population. Analysis of mitochondrial DNA (mtDNA indicated the presence of three distinct monophyletic clades of X. americanum species complex nematodes. Two clades contained nematodes found in association with nepovirus and the third contained divergent mtDNA sequences from three nematode populations from the western U.S. where nepovirus was absent. The inherent heterogeneity in ITS1 rDNA sequence data and lack of informative sites in 18S rDNA analysis suggests that mtDNA may be more useful in sorting

  15. Using mitogenomic and nuclear ribosomal sequence data to investigate the phylogeny of the Xiphinema americanum species complex.

    Science.gov (United States)

    Zasada, Inga A; Peetz, Amy; Howe, Dana K; Wilhelm, Larry J; Cheam, Daravuth; Denver, Dee R; Smythe, Ashleigh B

    2014-01-01

    Nematodes within the Xiphinema americanum species complex are economically important because they vector nepoviruses which cause considerable damage to a variety of agricultural crops. The taxonomy of X. americanum species complex is controversial, with the number of putative species being the subject of debate. Accurate phylogenetic knowledge of this group is highly desirable as it may ultimately reveal genetic differences between species. For this study, nematodes belonging to the X. americanum species complex, including potentially mixed species populations, were collected from 12 geographically disparate locations across the U.S. from different crops and in varying association with nepoviruses. At least four individuals from each population were analyzed. A portion of the 18S nuclear ribosomal DNA (rDNA) gene was sequenced for all individuals while the internal transcribed spacer region 1 (ITS1) of rDNA was cloned and 2 to 6 clones per individual were sequenced. Mitochondrial genomes for numerous individuals were sequenced in parallel using high-throughput DNA sequencing (HTS) technology. Phylogenetic analysis of the 18S rDNA revealed virtually identical sequences across all populations. Analysis of ITS1 rDNA sequences revealed several well-supported clades, with some degree of congruence with geographic location and viral transmission, but also numerous presumably paralogous sequences that failed to form clades with other sequences from the same population. Analysis of mitochondrial DNA (mtDNA) indicated the presence of three distinct monophyletic clades of X. americanum species complex nematodes. Two clades contained nematodes found in association with nepovirus and the third contained divergent mtDNA sequences from three nematode populations from the western U.S. where nepovirus was absent. The inherent heterogeneity in ITS1 rDNA sequence data and lack of informative sites in 18S rDNA analysis suggests that mtDNA may be more useful in sorting out the

  16. Viability of various weed seeds in anaerobic conditions (biogas plant)

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, S.; Hansen, J.

    1983-04-01

    Seeds from different weeds, Urtica urens L. (nettle), Solanum nigrum L. (nightshade), Avena fatua L. (wild oat-grass), Brassica napus L. (rape), Chenopodium album L. (goose-foot), were put into small polyester net bags, which were placed in biogas reactors containing cattle manure. These ''biogas reactors'' were placed at different temperatures . Net bags were taken out after 4.5, 10.5, 21.5, 38 and 53 days, and the seeds were tested for their viability by germination tests and the tetrazolium method. Concerning all seeds it was manifested that the viability decreased very steeply at 35degC. Most of the seeds had a T/sub 50/ at 2-5 days; Chenopodium album L seeds had a T/sub 50/ at 16 days. After 4.5 days it was not possible to find living Avena fatua L seeds. The decrease in viability was less steep at 20degC and even less steep at 2degC.

  17. The effect of sowing strategy, row distance and mechanical weed control on weeds and yield in organic winter wheat

    OpenAIRE

    Rasmussen, Ilse A.

    2002-01-01

    A series of field experiments were carried out in winter wheat grown under organic conditions in Denmark on fields with different weed pressure. The treatments were sowing strategy (normal sowing time, late sowing and false seedbed), row distance (12 cm and 24 cm row distance) and weed control method (untreated, mechanical weed control (weed harrowing at 12 cm supplemented with row hoeing at 24 cm), and herbicide weed control). Weed biomass was largest at the normal sowing time and was reduce...

  18. Pollen viability and meiotic analysis of Solanum commersonii commersonii Dun., Solanum commersonii malmeanum Bitt. and Solanum tuberosum L.

    Directory of Open Access Journals (Sweden)

    Alexandre Alonso Alves

    2007-01-01

    Full Text Available Meiotic abnormalities in potato hamper sexual recombination, due to their influence on pollen production andviability rate. In this study we evaluated pollen viability and meiosis of three clones of Solanum commersonii commersoniiDun. (SCC, two of Solanum commersonii malmeanum Bitt. (SCM and seven clones and four cultivars of Solanum tuberosumL., with the purpose of indicating promising genotypes for genetic breeding of potato. Early chromosome migration atmetaphases I and II and chromosome pairing anomalies were the main causes of pollen inviability in the evaluated genotypes.Clones SCC 07 and SCM 60 are the most suitable for sexual recombination, owing to the high percentage of viable pollengrains and low frequencies of meiotic abnormalities.

  19. Weeds in a Changing Climate: Vulnerabilities, Consequences, and Implications for Future Weed Management.

    Science.gov (United States)

    Ramesh, Kulasekaran; Matloob, Amar; Aslam, Farhena; Florentine, Singarayer K; Chauhan, Bhagirath S

    2017-01-01

    Whilst it is agreed that climate change will impact on the long-term interactions between crops and weeds, the results of this impact are far from clear. We suggest that a thorough understanding of weed dominance and weed interactions, depending on crop and weed ecosystems and crop sequences in the ecosystem, will be the key determining factor for successful weed management. Indeed, we claim that recent changes observed throughout the world within the weed spectrum in different cropping systems which were ostensibly related to climate change, warrant a deeper examination of weed vulnerabilities before a full understanding is reached. For example, the uncontrolled establishment of weeds in crops leads to a mixed population, in terms of C3 and C4 pathways, and this poses a considerable level of complexity for weed management. There is a need to include all possible combinations of crops and weeds while studying the impact of climate change on crop-weed competitive interactions, since, from a weed management perspective, C4 weeds would flourish in the increased temperature scenario and pose serious yield penalties. This is particularly alarming as a majority of the most competitive weeds are C4 plants. Although CO2 is considered as a main contributing factor for climate change, a few Australian studies have also predicted differing responses of weed species due to shifts in rainfall patterns. Reduced water availability, due to recurrent and unforeseen droughts, would alter the competitive balance between crops and some weed species, intensifying the crop-weed competition pressure. Although it is recognized that the weed pressure associated with climate change is a significant threat to crop production, either through increased temperatures, rainfall shift, and elevated CO2 levels, the current knowledge of this effect is very sparse. A few models that have attempted to predict these interactions are discussed in this paper, since these models could play an integral

  20. Dominant species of dicot-weeds and weed biodiversity in spring barley in Latvia.

    Science.gov (United States)

    Vanaga, I; Mintale, Z; Smirnova, O

    2010-01-01

    The composition of weed species in spring barley and weed biodiversity was evaluated in experiments in different growing seasons and with different previous crops. The aim of the experiments was to evaluate the composition of weed species in spring barley during a four year period in weather conditions of different growing seasons and with different previous crop as well as to assess the biodiversity in the experiments where the different groups of herbicides were applied. Over years and previous crops, the dicotyledonous weed community was dominated by Chenopodium album, followed by Viola arvensis. The herbicides from different groups had significant influences on the biodiversity of weeds.

  1. Weeds in a Changing Climate: Vulnerabilities, Consequences, and Implications for Future Weed Management

    Science.gov (United States)

    Ramesh, Kulasekaran; Matloob, Amar; Aslam, Farhena; Florentine, Singarayer K.; Chauhan, Bhagirath S.

    2017-01-01

    Whilst it is agreed that climate change will impact on the long-term interactions between crops and weeds, the results of this impact are far from clear. We suggest that a thorough understanding of weed dominance and weed interactions, depending on crop and weed ecosystems and crop sequences in the ecosystem, will be the key determining factor for successful weed management. Indeed, we claim that recent changes observed throughout the world within the weed spectrum in different cropping systems which were ostensibly related to climate change, warrant a deeper examination of weed vulnerabilities before a full understanding is reached. For example, the uncontrolled establishment of weeds in crops leads to a mixed population, in terms of C3 and C4 pathways, and this poses a considerable level of complexity for weed management. There is a need to include all possible combinations of crops and weeds while studying the impact of climate change on crop-weed competitive interactions, since, from a weed management perspective, C4 weeds would flourish in the increased temperature scenario and pose serious yield penalties. This is particularly alarming as a majority of the most competitive weeds are C4 plants. Although CO2 is considered as a main contributing factor for climate change, a few Australian studies have also predicted differing responses of weed species due to shifts in rainfall patterns. Reduced water availability, due to recurrent and unforeseen droughts, would alter the competitive balance between crops and some weed species, intensifying the crop-weed competition pressure. Although it is recognized that the weed pressure associated with climate change is a significant threat to crop production, either through increased temperatures, rainfall shift, and elevated CO2 levels, the current knowledge of this effect is very sparse. A few models that have attempted to predict these interactions are discussed in this paper, since these models could play an integral

  2. Ecological weed management by cover cropping : effects on weed growth in autumn and weed establishment in spring

    NARCIS (Netherlands)

    Kruidhof, H.M.; Bastiaans, L.; Kropff, M.J.

    2008-01-01

    Cover crops grown in the period between two main crops have potential as an important component of a system-oriented ecological weed management strategy. In late summer and autumn, the cover crop can suppress growth and seed production of weeds, whereas the incorporation of cover crop residues in sp

  3. Localization of Transmissible and Nontransmissible Viruses in the Vector Nematode Xiphinema americanum.

    Science.gov (United States)

    Wang, Shouhua; Gergerich, Rose C; Wickizer, Sandra L; Kim, Kyung S

    2002-06-01

    ABSTRACT The inner lining of the food canal of nematodes that transmit plantinfecting viruses is regarded as the retention region of viruses. To characterize the location of transmissible and nontransmissible viruses in the vector nematode Xiphinema americanum, three nepoviruses, Tobacco ringspot virus (TRSV), Tomato ringspot virus(TomRSV), and Cherry leaf roll virus(CLRV), and one non-nematode-transmissible virus, Squash mosaic virus (SqMV), were evaluated for transmission efficiency and localization sites in the nematode. Transmission trials showed highest transmission efficiency for TomRSV (38% with 1 and 100% with 10 nematodes, respectively), intermediate efficiency for TRSV (27% with 1 and 65% with 10 nematodes, respectively), and no transmission for CLRV and SqMV. Electron microscopy and immunofluorescent labeling revealed that TRSV was primarily localized to the lining of the lumen of the stylet extension and the anterior esophagus, but only rarely in the triradiate lumen. Within a nematode population, particles of TRSV were no longer observed in these three regions 10 weeks after acquisition, and it is assumed that there was gradual and random loss of the virus from these areas. The percentage of nematodes that were labeled by virus-specific immunofluorescent labeling in a population of viruliferous nematodes decreased gradually after TRSV acquisition when the nematodes were placed on a nonhost of the virus, and the loss of immunofluorescent labeling paralleled the decrease in the ability of the nematode population to transmit the virus. TomRSV was localized only in the triradiate lumen based on thin-section electron microscopy. No virus-like particles were observed in any part of the food canal of nematodes that had fed on CLRV-infected plants. Virus-like particles that appeared to be partially degraded were observed only in the triradiate lumen of nematodes that had fed on SqMV-infected plants. These results clarified the status of localization of two

  4. Effects of Planting Date, Time and Methods of Weed Control on Weed Density and Biomass in Cumin Fields

    Directory of Open Access Journals (Sweden)

    R. Ghorbani

    2011-01-01

    Full Text Available Abstract Two field experiments were carried out in order to evaluate the effect of planting date, method and date of weed control on weed density and biomass in the experimental research field, Faculty of Agriculture, Ferdowsi University of Mashhad, during 2006 and 2007. Treatments included planting date (30 December, 20 January and 30 February, weeding date (first true leaf, start of branching and beginning of flowering stages and weed control methods (hand weeding, fire treatment and control. The results showed that there were significant differences in the number of weeds between different sowing dates, weeding dates and control methods. The highest mean density and biomass of weeds were obtained on the planting date, 30 February, and when weed was controlled at the first leaf appearance stage with fire treatment. The most appropriate time for weed control was at the beginning of cumin flowering. Fire treatment reduced weed growth in the first half of growing season. However, hand weeding significantly reduced weed density and biomass in the second half of cumin growing season. The first planting date caused the lowest mean weed biomass and the highest cumin yield compared to later planting dates. Hand weeding treatment contained lower mean weed density and biomass compared to fire treatment, however, cumin yield was lower in hand weeding plots than fire treatment. Keywords: Cultural control, Cuminum cyminum, Fire, Hand weeding, Control time

  5. WEED SURVEYING OF PHACELIA (PHACELIA TANACETIFOLIA L.) AND EVALUATING THE EFFICIENCY OF THE WEED CONTROL.

    Science.gov (United States)

    Horváth, E; Szabó, R

    2014-01-01

    The experiment was set up in an area of 9 ha that was split into 4 plots: in plot 1 the row spacing was 12 cm and the seeding rate was 10 kg; in plot 2 the row spacing was 24 cm and the seeding rate was 10 kg; in plot 3 the row spacing was 24 cm and the seeding rate was 8 kg; in plot 4 the row spacing was 12 cm and the seeding rate was 8 kg. After the weed surveying, the total weed coverage was established as follows: in plot 1 the total weed coverage was 11.34%, in plot 2 it was 12.3%, in plot 3 it was 18%, and in plot 4 the total weed coverage was 15%. Based on the weed survey, on the test area the following dicotyledon weeds belonging to the T4 Raunkiaer plant life-form category occupied the highest percentage: heal-all, black-bindweed, goosefoot. The proportion of the perennial dicotyledons: field bindweed (G3), tuberous pea (G1), white campion (H3) was negligible. In all four cases the weed control was executed using the same herbicide in the same doses and with regard to the weed species it showed the same level of efficiency. The smaller row spacing and higher seeding rate has a beneficial effect on the weed suppressing capacity of the crop, the crop's weed suppressing capacity is better and the development of the weeds becomes worse.

  6. A new tetraploid species of Solanum L. sect. Solanum (Solanaceae from Tanzania

    Directory of Open Access Journals (Sweden)

    Mkabwa L.K. Manoko

    2012-08-01

    Full Text Available Solanum umalilaense Manoko sp. nov. (Solanaceae is described from the Umalila area, in the southern highlands of Tanzania. Its novelty is supported with both morphological and AFLP data. Phenetic and phylogenetic analyses place S. umalilaense as a unique and well-supported taxon among tetraploid species of Solanum sect. Solanum from Africa. It can be distinguished from other African species by its extremely developed branching, each branch producing many multi-flowered inflorescences, flowers with short calyx lobes and its persistent, small, light yellowish brown fruits.

  7. IMPORTANCE OF CRITICAL PERIOD OF WEED COMPETITION FOR CROP GROWING

    Directory of Open Access Journals (Sweden)

    Marijana Ivanek-Martinčić

    2010-06-01

    Full Text Available A concept of critical period of weed competition has been introduced for more than 40 years ago. The concept is based on the assumption that weeds are not equally harmful to a crop during the whole season and that there is a period in crop development in which weeds impact on the yield is the biggest. This period is called critical period of weed competition (CPWC, critical period of weed interference, or critical period of weed control. There is a difference in CPWC between crops, but CPWC for a certain crop can vary a lot because it depends on many factors which can affect the crop or weeds competition ability. The critical period of weed competition identification is essential for integrated weed control and precise planning of a weed control strategy as well as for rationale use of herbicides and other weed control measures.

  8. Weeding the Library Media Center Collections.

    Science.gov (United States)

    Buckingham, Betty Jo

    These guidelines for weeding library media collections are addressed to elementary and secondary school library media centers and to community college and vocational school library resource centers in Iowa. The publication includes some philosophy about weeding, and specific guidelines are summarized in bold-faced type for ease of use. The…

  9. Obsolescence, Weeding, and the Utilization of Space.

    Science.gov (United States)

    Lancaster, F. W.

    1988-01-01

    Suggests an objective approach to weeding library materials and discusses ways of measuring obsolescence and of controlling variables to provide a true picture of aging. Weeding is shown to improve space utilization and the quality of a collection. (5 references) (MES)

  10. Weeded Books Inspire Student Art Projects

    Science.gov (United States)

    Lincoln, Margaret

    2004-01-01

    The rationale behind weeding books is to remove dated, obsolete, erroneous material and worn books in disrepair from the collection to make room for current titles. Students of Lakeview have discovered an innovative idea of creating an altered book from the weeded book by taking a hardcover book and changing the original cover by means of a…

  11. Weed Recognition Framework for Robotic Precision Farming

    DEFF Research Database (Denmark)

    Kounalakis, Tsampikos; Triantafyllidis, Georgios; Nalpantidis, Lazaros

    2016-01-01

    In this paper, we introduce a novel framework which applies known image features combined with advanced linear image representations for weed recognition. Our proposed weed recognition framework, is based on state-of-the-the art object/image categorization methods exploiting enhanced performance ...

  12. Molecular biology approaches to weed management

    Science.gov (United States)

    Global climate change appears to be favorable for invasive weed development and spread because invasive species in general are proficient at succeeding in new environments. To worsen matters, herbicide-resistant weeds have become a severe threat in modern agricultural systems due to the extensive us...

  13. Weeds as important vegetables for farmers

    NARCIS (Netherlands)

    Cruz Garcia, G.S.; Price, L.L.

    2012-01-01

    The objective of this study was to investigate the multiple uses and cognitive importance of edible weeds in Northeast Thailand. Research methods included focus group discussions and freelistings. A total of 43 weeds consumed as vegetable were reported, including economic, naturalized, agricultural

  14. An autonomous weeding robot for organic farming

    NARCIS (Netherlands)

    Bakker, T.; Asselt, van C.J.; Bontsema, J.; Müller, J.; Straten, van G.

    2006-01-01

    The objective of this research is the replacement of hand weeding in organic farming by a device working autonomously at ¯eld level. The autonomous weeding robot was designed using a structured design approach, giving a good overview of the total design. A vehicle was developed with a diesel engine,

  15. Weed detection in 3D images

    NARCIS (Netherlands)

    Piron, A.; Heijden, van der F.; Destain, M.F.

    2011-01-01

    Machine vision has been successfully used for mechanical destruction of weeds between rows of crops. Knowledge of the position of the rows where crops should be growing and the assumption that plants growing outside such positions are weeds may be used in such systems. However for many horticultural

  16. Weed management strategies for castor bean crops

    Directory of Open Access Journals (Sweden)

    Augusto Guerreiro Fontoura Costa

    2014-04-01

    Full Text Available Castor bean crops are agriculturally relevant due to the quality and versatility of their oil, both for the chemical industry and for biodiesel production. Proper weed management is important for both the cultivation and the yield of castor bean crops; therefore, the intention of the present work is to review pertinent information regarding weed management, including the studies regarding weed interference periods, chemical controls for use in different crop production systems and herbicide selectivity, for castor bean crops. Weed science research for castor bean crops is scarce. One of the main weed management challenges for castor bean crops is the absence of herbicides registered with the Ministry of Agriculture, Livestock and Food Supply (MALFS. Research for viable herbicides for weed control in castor bean crops should be directed by research and/or rural extension institutions, associations and farmers cooperatives, as well as by manufactures, for the registration of these selective herbicides, which would be primarily used to control eudicotyledons in castor bean crops. New studies involving the integration of weed control methods in castor bean also may increase the efficiency of weed management, for both small farmers using traditional crop methods in the Brazilian Northeast region, as well as for areas with the potential for large scale production, using conservation tillage systems, such as the no-tillage crop production system.

  17. Weeds as important vegetables for farmers

    NARCIS (Netherlands)

    Cruz Garcia, G.S.; Price, L.L.

    2012-01-01

    The objective of this study was to investigate the multiple uses and cognitive importance of edible weeds in Northeast Thailand. Research methods included focus group discussions and freelistings. A total of 43 weeds consumed as vegetable were reported, including economic, naturalized, agricultural

  18. An autonomous weeding robot for organic farming

    NARCIS (Netherlands)

    Bakker, T.; Asselt, van C.J.; Bontsema, J.; Müller, J.; Straten, van G.

    2006-01-01

    The objective of this research is the replacement of hand weeding in organic farming by a device working autonomously at ¯eld level. The autonomous weeding robot was designed using a structured design approach, giving a good overview of the total design. A vehicle was developed with a diesel engine,

  19. A new approach to identify species in Xiphinema americanum sensu lato.

    Science.gov (United States)

    Prior, T; Hockland, S; Decraemer, W

    2010-01-01

    Four putative species belonging to the X. americanum group are known to transmit American nepoviruses and these nematodes and viruses are listed in European quarantine legislation. Identification of species in this group is therefore of particular importance for phytosanitary purposes, but is problematic because of the similar morphology of the putative species. As part of the Synthesys project BE-TAF 1769, eight collaborative institutions contributed material to Fera for study. Video technology allowed the best records of type material and in conjunction with photographic images created a 'virtual' collection of images that relies less on the deteriorating quality of museum specimens. Revised definitions of lip region and tail shape are considered to be the most stable characters for differentiation. Position of the amphidial aperture, development of the odontostyle collar and some established morphometric characters are considered of limited use although they retain value for latter stages of identification.

  20. Evaluation of Broadleaf Weeds Control with Selectivity of Post-Emergence Herbicides in Sugar Beet (Beta vulgaris L.

    Directory of Open Access Journals (Sweden)

    Ali Asghar CHITBAND

    2014-12-01

    Full Text Available The reduction of herbicide applications is a main research priority in recent years. In order to study the effect of individual post-emergence application of sugar beet broad-leaf herbicides at four to six true-leaf stage of weeds, experiments were conducted during 2013. Treatments included untreated control and several rates of desmedipham + phenmedipham + ethofumesate, chloridazon and clopyralid on Portulaca oleracea, Solanum nigrum, Amaranthus retroflexus and Chenopodium album. A completely randomized layout with three replications was used for each herbicide. Three weeks after spraying (WAS, plants were harvested and measured their dry weight. These herbicides were more effective to control Portulaca oleracea than other weeds, thereupon minimum dose required for a satisfactory efficacy of 90% reduction of Portulaca oleracea aboveground dry matter (ED90 were 299.22, 1138.31 and 129.44 g a.i ha-1 of desmedipham + phenmedipham + ethofumesate, chloridazon and clopyralid, respectively. Solanum nigrum was more affected by clopyralid application (132.40 g a.i ha-1, and did not make significant difference in Portulaca oleracea. Chloridazon had lower effect for control of Chenopodium album due to existence of powdery covering on abaxial side of the leaves. Biomass ED50 or ED90, based on log-logistic dose–response curves, for Chenopodium album was considerably higher than other species. These results showed that tank mixtures with other herbicides may be required for satisfactory weed control and reduction in applied herbicides doses.

  1. Characterization of the bacterial communities of life stages of free living lone star ticks (Amblyomma americanum).

    Science.gov (United States)

    Williams-Newkirk, Amanda Jo; Rowe, Lori A; Mixson-Hayden, Tonya R; Dasch, Gregory A

    2014-01-01

    The lone star tick (Amblyomma americanum) is an abundant and aggressive biter of humans, domestic animals, and wildlife in the southeastern-central USA and an important vector of several known and suspected zoonotic bacterial pathogens. However, the biological drivers of bacterial community variation in this tick are still poorly defined. Knowing the community context in which tick-borne bacterial pathogens exist and evolve is required to fully understand the ecology and immunobiology of the ticks and to design effective public health and veterinary interventions. We performed a metagenomic survey of the bacterial communities of questing A. americanum and tested 131 individuals (66 nymphs, 24 males, and 41 females) from five sites in three states. Pyrosequencing was performed with barcoded eubacterial primers targeting variable 16S rRNA gene regions 5-3. The bacterial communities were dominated by Rickettsia (likely R. amblyommii) and an obligate Coxiella symbiont, together accounting for 6.7-100% of sequences per tick. DNAs from Midichloria, Borrelia, Wolbachia, Ehrlichia, Pseudomonas, or unidentified Bacillales, Enterobacteriaceae, or Rhizobiales groups were also detected frequently. Wolbachia and Midichloria significantly co-occurred in Georgia (p<0.00001), but not in other states. The significance of the Midichloria-Wolbachia co-occurrence is unknown. Among ticks collected in Georgia, nymphs differed from adults in both the composition (p = 0.002) and structure (p = 0.002) of their bacterial communities. Adults differed only in their community structure (p = 0.002) with males containing more Rickettsia and females containing more Coxiella. Comparisons among adult ticks collected in New York and North Carolina supported the findings from the Georgia collection despite differences in geography, collection date, and sample handling, implying that the differences detected are consistent attributes. The data also suggest that some members of the

  2. Characterization of the bacterial communities of life stages of free living lone star ticks (Amblyomma americanum.

    Directory of Open Access Journals (Sweden)

    Amanda Jo Williams-Newkirk

    Full Text Available The lone star tick (Amblyomma americanum is an abundant and aggressive biter of humans, domestic animals, and wildlife in the southeastern-central USA and an important vector of several known and suspected zoonotic bacterial pathogens. However, the biological drivers of bacterial community variation in this tick are still poorly defined. Knowing the community context in which tick-borne bacterial pathogens exist and evolve is required to fully understand the ecology and immunobiology of the ticks and to design effective public health and veterinary interventions. We performed a metagenomic survey of the bacterial communities of questing A. americanum and tested 131 individuals (66 nymphs, 24 males, and 41 females from five sites in three states. Pyrosequencing was performed with barcoded eubacterial primers targeting variable 16S rRNA gene regions 5-3. The bacterial communities were dominated by Rickettsia (likely R. amblyommii and an obligate Coxiella symbiont, together accounting for 6.7-100% of sequences per tick. DNAs from Midichloria, Borrelia, Wolbachia, Ehrlichia, Pseudomonas, or unidentified Bacillales, Enterobacteriaceae, or Rhizobiales groups were also detected frequently. Wolbachia and Midichloria significantly co-occurred in Georgia (p<0.00001, but not in other states. The significance of the Midichloria-Wolbachia co-occurrence is unknown. Among ticks collected in Georgia, nymphs differed from adults in both the composition (p = 0.002 and structure (p = 0.002 of their bacterial communities. Adults differed only in their community structure (p = 0.002 with males containing more Rickettsia and females containing more Coxiella. Comparisons among adult ticks collected in New York and North Carolina supported the findings from the Georgia collection despite differences in geography, collection date, and sample handling, implying that the differences detected are consistent attributes. The data also suggest that some members of

  3. Population and Evolutionary Genomics of Amblyomma americanum, an Expanding Arthropod Disease Vector.

    Science.gov (United States)

    Monzón, Javier D; Atkinson, Elizabeth G; Henn, Brenna M; Benach, Jorge L

    2016-05-12

    The lone star tick, Amblyomma americanum, is an important disease vector and the most frequent tick found attached to humans in the eastern United States. The lone star tick has recently experienced a rapid range expansion into the Northeast and Midwest, but despite this emerging infectious threat to wildlife, livestock, and human health, little is known about the genetic causes and consequences of the geographic expansion. In the first population genomic analysis of any tick species, we characterize the genetic diversity and population structure of A. americanum across its current geographic range, which has recently expanded. Using a high-throughput genotyping-by-sequencing approach, we discovered more than 8,000 single nucleotide polymorphisms in 90 ticks from five locations. Surprisingly, newly established populations in New York (NY) and Oklahoma (OK) are as diverse as historic range populations in North and South Carolina. However, substantial population structure occurs among regions, such that new populations in NY and OK are genetically distinct from historic range populations and from one another. Ticks from a laboratory colony are genetically distinct from wild populations, underscoring the need to account for natural variation when conducting transmission or immunological studies, many of which utilize laboratory-reared ticks. An FST-outlier analysis comparing a recently established population to a long-standing population detected numerous outlier sites, compatible with positive and balancing selection, highlighting the potential for adaptation during the range expansion. This study provides a framework for applying high-throughput DNA sequencing technologies for future investigations of ticks, which are common vectors of diseases.

  4. Detecting bugweed (Solanum mauritianum) abundance in plantation forestry using multisource remote sensing

    Science.gov (United States)

    Peerbhay, Kabir; Mutanga, Onisimo; Lottering, Romano; Bangamwabo, Victor; Ismail, Riyad

    2016-11-01

    The invasive weed Solanum mauritianum (bugweed) has infested large areas of plantation forests in KwaZulu-Natal, South Africa. Bugweed often forms dense infestations and rapidly capitalises on available natural resources hindering the production of forest resources. Precise assessment of bugweed canopy cover, especially at low abundance cover, is essential to an effective weed management strategy. In this study, the utility of AISA Eagle airborne hyperspectral data (393-994 nm) with the new generation Worldview-2 multispectral sensor (427-908 nm) was compared to detect the abundance of bugweed cover within the Hodgsons Sappi forest plantation. Using sparse partial least squares discriminant analysis (SPLS-DA), the best detection results were obtained when performing discrimination using the remotely sensing images combined with LiDAR. Overall classification accuracies subsequently improved by 10% and 11.67% for AISA and Worldview-2 respectively, with improved detection accuracies for bugweed cover densities as low as 5%. The incorporation of LiDAR worked well within the SPLS-DA framework for detecting the abundance of bugweed cover using remotely sensed data. In addition, the algorithm performed simultaneous dimension reduction and variable selection successfully whereby wavelengths in the visible (393-670 nm) and red-edge regions (725-734 nm) of the spectrum were the most effective.

  5. Weed species shifts in glyphosate-resistant crops.

    Science.gov (United States)

    Owen, Micheal D K

    2008-04-01

    The adoption of glyphosate-based crop production systems has been one of the most important revolutions in the history of agriculture. Changes in weed communities owing to species that do not respond to current glyphosate-based management tactics are rapidly increasing. Clearly, glyphosate-resistant crops (GRCs) do not influence weeds any more than non-transgenic crops. For most crops, the trait itself is essentially benign in the environment. Rather, the weed control tactics imposed by growers create the ecological selection pressure that ultimately changes the weed communities. This is seen in the adoption of conservation tillage and weed management programs that focus on one herbicide mode of action and have hastened several important weed population shifts. Tillage (disturbance) is one of the primary factors that affect changes in weed communities. The intense selection pressure from herbicide use will result in the evolution of herbicide-resistant weed biotypes or shifts in the relative prominence of one weed species in the weed community. Changes in weed communities are inevitable and an intrinsic consequence of growing crops over time. The glyphosate-based weed management tactics used in GRCs impose the selection pressure that supports weed population shifts. Examples of weed population shifts in GRCs include common waterhemp [Amaranthus tuberculatus (Moq ex DC) JD Sauer], horseweed (Conyza canadensis L), giant ragweed (Ambrosia trifida L) and other relatively new weed problems. Growers have handled these weed population shifts with varying success depending on the crop. Copyright (c) 2008 Society of Chemical Industry.

  6. Adapting weed management in rice to changing climates

    NARCIS (Netherlands)

    Rodenburg, J.; Meinke, H.B.

    2011-01-01

    This paper provides some of the scientific background on how projected environmental conditions could affect weeds and weed management in rice in Africa. Elevated CO2 levels may have positive effects on rice competitiveness with C4 weeds, but these are generally outnumbered by C3 species in weed pop

  7. Competitive oats for integrated weed management and organic rotations

    OpenAIRE

    Fradgley, Nick

    2014-01-01

    Using a competitive crop like oats is essential for integrated management of weed problems. Oats can compete well with weeds through efficient nutrient uptake, allelopathy and canopy cover shading. Weeds are suppressed by the crops tillering ability and varieties with good canopy cover. Some varieties can tolerate weeds better by having both good canopy cover and height.

  8. A rotational framework to reduce weed density in organic systems

    Science.gov (United States)

    Weeds are a major obstacle to successful crop production in organic farming. Producers may be able to reduce inputs for weed management by designing rotations to disrupt population dynamics of weeds. Population-based management in conventional farming has reduced herbicide use 50% because weed den...

  9. Weed Garden: An Effective Tool for Extension Education

    Science.gov (United States)

    Beck, Leslie; Patton, Aaron J.

    2015-01-01

    A weed garden was constructed to quantify and improve identification skills among clientele. The garden was planted with over 100 weed species based on surveys on problematic weeds. The weed garden proved useful for introducing additional hands-on learning activities into traditional lecture-based seminars. Through seminar and field day attendee…

  10. Delivering the barebones for designing more weed suppressive crop rotations

    NARCIS (Netherlands)

    Bastiaans, L.; Berghuijs, H.N.C.

    2011-01-01

    Even though crop rotation is often regarded as an important component of weed management, tools for optimising the weed-suppressive character of crop rotations are lacking. The long-term character of this strategy and the variety of weed-promoting and weed-suppressing conditions and events that are

  11. Weed Garden: An Effective Tool for Extension Education

    Science.gov (United States)

    Beck, Leslie; Patton, Aaron J.

    2015-01-01

    A weed garden was constructed to quantify and improve identification skills among clientele. The garden was planted with over 100 weed species based on surveys on problematic weeds. The weed garden proved useful for introducing additional hands-on learning activities into traditional lecture-based seminars. Through seminar and field day attendee…

  12. Algunos componentes esteroidales del solanum havanense jacq

    Directory of Open Access Journals (Sweden)

    Mario J. Basterrechea Rey

    2000-01-01

    Full Text Available Un nuevo alcaloide esteroidal llamado acetil etiolina, ha sido aislado de las hojas, tallos y raices del Solanum havanense Jacq y su estructura corresponde con (25S-16a-acetoxi-22.26-epiminocolest-5.22(N-dien-3ß-ol.

  13. Phytonutrient analysis of Solanum sisymbriifolium Lam. berries

    Science.gov (United States)

    Solanum sisymbriifolium Lam. (Litchi tomato) is grown ornamentally, and in Europe it is used as a trap crop for management of the potato cyst nematode (PCN). Its berries are edible, but little is known about their nutritional content. If more was known about their nutritional value this could provid...

  14. Flowerlocation in Solanum dulcamara L. (Solanaceae

    Directory of Open Access Journals (Sweden)

    Irina Zhuravlyeva

    2013-01-01

    Full Text Available The morphology of inflorescence of Solanum dulcamara is studied. Pseudolateral location of inflorescence relatively to plant body is set, the absence of bracteae and the sympodial type of growing of branches are found out. From W. Troll point of view the inflorescence of nightshade is defined as the polytelica synflorescence – complex dichasium.

  15. Biological weed control with soil fungi? Antagonistic effects of arbuscular mycorrhizal fungi on the growth of weeds

    NARCIS (Netherlands)

    Veiga, R.

    2012-01-01

    Excessive weed growth represents one of the major threats to crop production especially when reliance on herbicides is reduced. Biological weed control is an alternative, environmentally-sound method that, combined with other weed control practices, can contribute to an effective weed management in

  16. [Effects of weeding methods on weed community and its diversity in a citrus orchard in southwest Zhejiang].

    Science.gov (United States)

    Yao, He-Jin; Jin, Zong-Lai; Yang, Wei-Bin; Zhao, Jian-Hua; Zhang, Fan

    2010-01-01

    By using the research methods of ecological community, the effects of different weed management strategies including chemical weeding, manual weeding, and their combination on the weed community and its diversity in a citrus chard of main orange producing region in Quzhou City, Zhejiang Province were studied from June 2005 to May 2008. In control plots, there were 75 species and 25 families of weeds; after chemical weeding, manual weeding, and their combination, there were 46 species and 17 families, 59 species and 20 families, and 51 species and 18 families of weeds, respectively. The Margalef's species richness index, Shannon's diversity index, and Shannon's evenness index were the lowest after chemical weeding, but the highest after manual weeding, suggesting that chemical weeding had the greatest effects on the weed diversity in the citrus orchard. It was suggested that to sufficiently control the weeds while to maintain the weed diversity in the orchard weeds in southwest Zhejiang, the combination of chemical and manual weeding would be the best management strategy.

  17. Soil solarization for weed control in carrot

    Directory of Open Access Journals (Sweden)

    MARENCO RICARDO ANTONIO

    2000-01-01

    Full Text Available Soil solarization is a technique used for weed and plant disease control in regions with high levels of solar radiation. The effect of solarization (0, 3, 6, and 9 weeks upon weed populations, carrot (Daucus carota L. cv. Brasília yield and nematode infestation in carrot roots was studied in São Luís (2º35' S; 44º10' W, MA, Brazil, using transparent polyethylene films (100 and 150 mm of thickness. The maximum temperature at 5 cm of depth was about 10ºC warmer in solarized soil than in control plots. In the study 20 weed types were recorded. Solarization reduced weed biomass and density in about 50% of weed species, including Cyperus spp., Chamaecrista nictans var. paraguariensis (Chod & Hassl. Irwin & Barneby, Marsypianthes chamaedrys (Vahl O. Kuntze, Mitracarpus sp., Mollugo verticillata L., Sebastiania corniculata M. Arg., and Spigelia anthelmia L. Approximately 40% of species in the weed flora were not affected by soil mulching. Furthermore, seed germination of Commelina benghalensis L. was increased by soil solarization. Marketable yield of carrots was greater in solarized soil than in the unsolarized one. It was concluded that solarization for nine weeks increases carrot yield and is effective for controlling more than half of the weed species recorded. Mulching was not effective for controlling root-knot nematodes in carrot.

  18. Acquisition and expression of resistance by Bos indicus and Bos indicus X Bos taurus calves to Amblyomma americanum infestation.

    Science.gov (United States)

    George, J E; Osburn, R L; Wikel, S K

    1985-04-01

    Purebred and crossbred Bos indicus calves were infested 1, 2, or 3 times with 10 female and 5 male Amblyomma americanum. Resistance was acquired by both the purebred and the crossbred calves after 1 infestation and resulted in statistically significant decreases in the percentages of females that engorged, the mean weights of engorged females, and the mean weights of egg masses. Comparisons between breeds of the percent of female ticks that engorged during the first and second infestations indicate that purebred B. indicus expressed a stronger acquired resistance to A. americanum more readily than did crossbred animals. However, calves of both genetic compositions displayed similar levels of resistance during a third exposure. All tick-exposed and control animals were skin tested with salivary gland extracts of A. americanum, A. cajennense and Dermacentor andersoni. Control, uninfested calves, did not display significant cutaneous reactivity to these extracts. All calves that had been infested had immediate, 30-min, 5-hr and delayed, 24-hr, skin reactions to Amblyomma species antigens. Reactions to D. andersoni salivary antigens in tests of both purebred and crossbred calves with acquired resistance to A. americanum suggest that Amblyomma species salivary gland antigens might have cross reactive moieties with a salivary extract prepared from D. andersoni. Peripheral blood lymphocyte in vitro responsiveness to Amblyomma species antigens was detected in purebred calves after a first, second, and third infestation, indicating the presence of cells of the immune system capable of recognizing and undergoing blast transformation in response to tick salivary components.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Activity of Hydroxamic Acids from Secale cereale Against the Plant-Parasitic Nematodes Meloidogyne incognita and Xiphinema americanum.

    Science.gov (United States)

    Zasada, I A; Meyer, S L F; Halbrendt, J M; Rice, C

    2005-10-01

    ABSTRACT Cyclic hydroxamic acids are secondary metabolites found in the family Poaceae and have been implicated in the allelopathy of rye (Secale cereale). The toxicity of these compounds against plant-parasitic nematodes is unknown. DIBOA (2,4-dihydroxy-(2H)-1,4-benzoxazin-3(4H)-one), DIMBOA (2,4-hydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one), and their degradation products BOA (benzoxazolin-2(3H)-one) and MBOA (6-methoxy-benzoxazolin-2(3H)-one) were screened in vitro against Meloidogyne incognita second-stage juveniles (J2) and eggs and mixed-stages of Xiphinema americanum. Xiphinema americanum was more sensitive to DIBOA and DIMBOA than M. incognita J2, with a maximum apparent mortality of 96 and 92% compared to 73 and 72% at 90 mug/ml. Eggs of M. incognita were less sensitive to the hydroxamic acids than J2; only DIBOA resulted in a 50% reduction in egg hatch, with a lethal concentration (LC(50)) of 74 mug/ml compared to 21 mug/ml for J2. When M. incognita J2 were exposed to DIBOA for 48 h and the compound was removed and replaced with water, the LC(50) value increased from 21.0 to 40.7 mug/ml. MBOA was not toxic to X. americanum or M. incognita eggs, but was toxic to M. incognita J2, with LC(50) values of 44 and 20 mug/ml before and after the compound was removed and replaced with water. BOA was the least toxic hydroxamic acid tested; it did not reduce M. incognita egg hatch after 1 week of exposure or increase X. americanum mortality after 24 h of exposure. While in vitro studies provide a valuable starting point in determining the toxicity of the chemical component of rye, the relevance of the data to soil remains to be determined.

  20. Suppression of Amblyomma americanum (Ixodida: Ixodidae) for Short-Term Field Operations Utilizing Cypermethrin and Lambda-Cyhalothrin

    Science.gov (United States)

    2014-05-01

    two grids (42 by 42 m) were established that contained a mix of open grasses and dense brush . Each grid was evenly divided into 49 plots,witheachplot...the label rate of one tablet in 1.9 liters of water, delivering 15 mg a.i./m2. Hand pump compression sprayers were used to apply the acaricides...developments in invertebrate repellents. ACS Symposium Series, American Chemical Society, Wash - ington, DC. Table 1. Host-seeking A. americanum abundance

  1. A study of weeding policies in eleven TALON resource libraries.

    Science.gov (United States)

    Goldstein, C H

    1981-01-01

    A study was made of the weeding policies and practices of eleven TALON resource libraries. The results indicated that although weeding, or collection evaluation as it is also known, was performed by most of the libraries, few had a written policy. The reasons for weeding and the types of weeding done by the libraries are described. A discussion of the prevalent means of disposition of withdrawn materials and of the obstacles to cooperative weeding is included. PMID:7248594

  2. A study of weeding policies in eleven TALON resource libraries.

    Science.gov (United States)

    Goldstein, C H

    1981-07-01

    A study was made of the weeding policies and practices of eleven TALON resource libraries. The results indicated that although weeding, or collection evaluation as it is also known, was performed by most of the libraries, few had a written policy. The reasons for weeding and the types of weeding done by the libraries are described. A discussion of the prevalent means of disposition of withdrawn materials and of the obstacles to cooperative weeding is included.

  3. A study of weeding policies in eleven TALON resource libraries.

    OpenAIRE

    Goldstein, C H

    1981-01-01

    A study was made of the weeding policies and practices of eleven TALON resource libraries. The results indicated that although weeding, or collection evaluation as it is also known, was performed by most of the libraries, few had a written policy. The reasons for weeding and the types of weeding done by the libraries are described. A discussion of the prevalent means of disposition of withdrawn materials and of the obstacles to cooperative weeding is included.

  4. Critical period of weed control In cumin (Cuminum cyminum)

    OpenAIRE

    azade hoseyni; alireza koochaki; mehdi nassiri mahalati

    2009-01-01

    In order to evaluate the critical period of weed control in Cumin, an experiment with Complete Randomized Block Design and three replications was conducted in experimental field of Faculty of Agriculture, Ferdowsi University of Mashhad, During 2004-2005 growing season. Treatments included different combinations of weed free and weed infested periods (20, 30, 40 and 80 days after germination) plus weedy check and weed free check. Critical period weed control was evaluated with Gompertz and Log...

  5. Research on the development of weed-suppressing rice varieties

    Institute of Scientific and Technical Information of China (English)

    Shaochuan ZHOU; Decheng LU; Hong LI; Daoqiang HUANG; Ruowei MIAO

    2009-01-01

    This study was conducted to develop weed-suppressing rice varieties in a weed-suppressing nursery by specific secondary metabolite markers of allelopathic potential. Weed-suppressing rice variety Feng-Hua-Zhan was screened out by a specific secondary metabolite marker of allelopathic potential. Weed-suppressing rice No. 1, a new rice line with good quality, was also developed using this method. The genetic backgrounds and research directions of weed-suppressing rice varieties are discussed in this paper.

  6. Nutritional Value and Toxins in Various Noxious Weeds

    OpenAIRE

    Burritt, Beth; Hart, Rae Ann

    2014-01-01

    Teaching animals to eat noxious weeds may be a solution to reducing noxious weeds. Grazing animals often avoid eating weeds due to novelty even though weeds are often as nutritious as many of our planted pasture and rangelands species. This fact sheet provides livestock producers with the nutritive values of many common weeds. These values were summarized from a variety of peer-reviewed journal articles.

  7. Combining a weed traits database with a population dynamics model predicts shifts in weed communities

    DEFF Research Database (Denmark)

    Storkey, Jonathan; Holst, Niels; Bøjer, Ole Mission;

    2015-01-01

    A functional approach to predicting shifts in weed floras in response to management or environmental change requires the combination of data on weed traits with analytical frameworks that capture the filtering effect of selection pressures on traits. A weed traits database (WTDB) was designed......, populated and analysed, initially using data for 19 common European weeds, to begin to consolidate trait data in a single repository. The initial choice of traits was driven by the requirements of empirical models of weed population dynamics to identify correlations between traits and model parameters....... These relationships were used to build a generic model, operating at the level of functional traits, to simulate the impact of increasing herbicide and fertiliser use on virtual weeds along gradients of seed weight and maximum height. The model generated ‘fitness contours’ (defined as population growth rates) within...

  8. Presence, genetic variability, and potential significance of "Candidatus Midichloria mitochondrii" in the lone star tick Amblyomma americanum.

    Science.gov (United States)

    Williams-Newkirk, Amanda Jo; Rowe, Lori A; Mixson-Hayden, Tonya R; Dasch, Gregory A

    2012-11-01

    We used next generation sequencing to detect the bacterium "Candidatus Midichloria mitochondrii" for the first time in lone star ticks (Amblyomma americanum) from the eastern United States. 177 individuals and 11 tick pools from seven sites in four states were tested by pyrosequencing with barcoded 16S rRNA gene eubacterial primers targeting variable regions 5-3. Average infection prevalence was 0.15 across all surveyed populations (range 0-0.29) and only the site with the smallest sample size (n = 5) was negative. Three genotypes differing by 2.6-4.1 % in a 271 bp region of 16S rRNA gene were identified. Two variants co-occurred in sites in North Carolina and New York, but were not observed in the same tick at those sites. The third genotype was found only in Georgia. Phylogenetic analysis of this fragment indicated that the three variants are more closely related to "Candidatus Midichloria mitochondrii" genotypes from other tick species than to each other. This variation suggests that multiple independent introductions occurred in A. americanum which may provide insight into bacterial spread within its ecosystem and parasitism on this tick. Whether the presence of this bacterium affects acquisition or maintenance of other pathogens and symbionts in A. americanum or the survival, biology and evolution of the tick itself is unknown.

  9. On the Parable of Weeds and Wheat

    Institute of Scientific and Technical Information of China (English)

    HUANG Wei

    2013-01-01

    This paper probes on one of the famous parables of Jesus-the Wheat and Weeds, and demonstrates some implied meaning and morals connoted in it. Through an interesting contrast between the calm restraint of the householder and high anxi-ety of his slaves, this parable suggests that people should stay calm and learn from God to be tolerate and lenient religiously to“let wheat and weeds grow together until the harvest”. Meanwhile, God drops a subtle hint to seed wheat positively in stead of sug-gesting people to remove weeds negatively.

  10. The Evaluation and the Comparison of the Effect of Mechanical Weeding Systems on Rice Weed

    Directory of Open Access Journals (Sweden)

    Fazlollah Eskandari Cherati

    2012-08-01

    Full Text Available In order to study the influence of different methods of controlling weeds such as mechanical weeding and mechanical weeder efficiency analysis in mechanical cultivation conditions, in farming year of 2011 an experiment was done in a farm in coupling and development of technology center in Haraz, Iran. The treatments consisted of (I control treatment: where no weeding was done, (II use of mechanical weeding without engine and (III power mechanical weeding. Results showed that experimental treatments had significantly different effects (p = 0.05 on yield traits and number of filled grains per panicle, while treatments had the significant effects on grain weight and dry weight of weeds in the first, second and third weeding methods at 1% of confidence level. Treatment (II had its most significant effect on number of filled grains per panicle and yield performance standpoint, which was 3705.97 kg/ha in its highest peak. Treatment (III was ranked as second influential with 3559.8 kg/ha. In addition, under (I treatments, 2364.73 kg/ha of yield produced. The minimum dry weights of weeds in all weeding methods were related to the treatment (II, (III and (I, respectively. The correlation coefficient analysis showed that total yield had a significant positive correlation with the panicle grain yield per plant (r = 0.55* and the number of grains/panicle (r = 0.57* and the number of filled grains (r = 0.63*. Total rice yield also had negative correlation of r = -0.64* with weed dry weight at second weed sampling time (17 DAT. The weed dry weight at third and fourth sampling times (24 and 40 DAT had negative correlations of -0.65** and r = -0.61* with rice yield, respectively.

  11. Non-chemical Control of Root Parasitic Weeds with Biochar

    Directory of Open Access Journals (Sweden)

    Hanan Eizenberg

    2017-06-01

    Full Text Available This study tested whether soil-applied biochar can impact the seed germination and attachment of root parasitic weeds. Three hypotheses were evaluated: (i biochar adsorbs host-exuded signaling molecules; (ii biochar activates plants’ innate system-wide defenses against invasion by the parasite; and (iii biochar has a systemic influence on the amount of seed germination stimulant produced or released by the host plant. Three types of experiments were performed: (I pot trials with tomato (Solanum lycopersicum infested with Phelipanche aegyptiaca PERS. (Egyptian broomrape and three different types of biochar at concentrations ranging from 0 to 1.5% weight, wherein tomato plant biomass, P. aegyptiaca biomass, and number of P. aegyptiaca-tomato root attachments were quantified; (II split-root biochar/no-biochar experiments under hydroponic growing conditions performed in polyethylene bags with tomato plant rootings, wherein P. aegyptiaca seed germination percentage and radicle attachment numbers were quantified; and (III germination trials, wherein the effect of biochar adsorption of GR-24 (artificial germination stimulant on P. aegyptiaca seed germination was quantified. Addition of biochar to the pot soil (Experiment I resulted in lower levels of P. aegyptiaca infection in the tomato plants, mainly through a decrease in the number of P. aegyptiaca attachments. This led to improved tomato plant growth. In Experiment II, P. aegyptiaca seed germination percentage decreased in the biochar-treated root zone as compared with the no-biochar control root zone; P. aegyptiaca radicle attachment numbers decreased accordingly. This experiment showed that biochar did not induce a systemic change in the activity of the stimulant molecules exuded by the tomato roots, toxicity to the radicles, or a change in the ability of the radicles to penetrate the tomato roots. The major cause for the decrease in germination percentage was physical adsorption of the

  12. Alien species in the Finnish weed flora

    Directory of Open Access Journals (Sweden)

    T. HYVÖNEN

    2008-12-01

    Full Text Available The present study aimed at assessing the invasion of alien weed species in Finland based on a review of their occurrence in the Finnish weed flora. The evaluation was conducted for the three phases of the invasion process, i.e. introduction, naturalization and invasion. The literature review revealed that 815 alien weed species occur in Finland of which 314 are regarded as naturalized. Based on their occurrence in different climate zones, the risk of naturalization of new harmful alien weed species was deemed low for those species not currently found in Finland, but higher for species occurring as casual aliens in Finland. In the latter group, 10 species of concern were detected. Exploration of the distribution patterns of naturalized species within Finland revealed species occupancy to be dependent on the residence time of the species. Established neophytes can be expected to extend their ranges and to increase occupation of agricultural habitats in the future.;

  13. WHITE BLISTER SPECIES (Albuginaceae ON WEEDS

    Directory of Open Access Journals (Sweden)

    Karolina Vrandečić

    2011-06-01

    Full Text Available The obligate fungi inside the family Albuginaceae are widespread world wide and cause white rust or white blister disease. Mycopopulation of weeds has been researched within the project „The role of weeds in epidemiology of row-crop diseases“. The aim of this research was to identify white blister species occurring on weeds in Eastern Croatia. Weed plants with disease symptoms characteristic for white blister species have been collected since 2001 on location Slavonia and Baranja country. Determination of white blister species was based on morphological characters of pathogen and the host. Wilsoniana bliti was determined on Amaranthus retroflexus and Amaranthus hybridus leaves. Capsella bursa pastoris is a host for Albugo candida. Ambrosia artemisiifolia is a host for Pustula sp. and Cirsium arvense was found to be host for Pustula spinulosa. Wilsoniana portulaceae was determined on Portulaca oleracea.

  14. Periods of weed interference in cowpea

    Directory of Open Access Journals (Sweden)

    Maria José Pinheiro Corrêa

    2015-12-01

    Full Text Available This work aimed to determine the periods weed interference in cowpea. The experimental design was randomized blocks, and the treatments consisted of periods of control or coexistence with the culture. The periods of control or weed coexistence after culture emergence were: 0-10, 0-20, 0-30, 0-40, 0-50, 0-60 and 0 – 80 days after crop emergence. The main weed density were: AlternantheratenellaColla,CyperusrotundusL., Digitariaciliaris(Retz. Koeler, Eleusineindica(L.Gaertn,MollugoverticillataL.Considering 5% of tolerance in cowpea yield reduction, the period prior interference was 8 days after emergence (DAE, total period of interference prevention was 53 DAE and critical period of interference prevention between 8 and 53 DAE. Weed interference reduced the grainyield up to 46%.

  15. Bioenergy potential of eight common aquatic weeds

    Energy Technology Data Exchange (ETDEWEB)

    Abbasi, S.A.; Nipaney, P.C.; Schaumberg, G.D. (Pondicherry (Central) Univ. (IN). Salim Ali School of Ecology)

    1990-01-01

    Eight common aquatic weeds Salvinia molesta, Hydrilla verticillata, Nymphaea stellata, Azolla pinnata, Ceratopteris sp. Scirpus sp. Cyperus sp, and Utricularia reticulata were digested anaerobically to produce methane. The carbon to nitrogen (C/N) ratio, carbon to phosphorus (C/P) ratio, and the volatile solids (VS) content of the weeds varied widely. No trend between these factors and the methane yield was discernable; the possible reasons are discussed. The energy potential of the weeds per unit area of the weed crop was worked out. Natural stands of salvinia, such as the one employed in the present investigation, would yield energy (methane) of the order of 10{sup 8} Kcal/ha/yr. (author).

  16. Using Weeds and Wildflowers to Study Plants.

    Science.gov (United States)

    Nowak, Nancy

    1984-01-01

    Offers suggestions for activities in which local weeds and wildflowers are used to study a variety of topics. These topics include classification, ecological succession, and mapping. Also lists the types of experiments students can perform with these plants. (JN)

  17. Using Weeds and Wildflowers to Study Plants.

    Science.gov (United States)

    Nowak, Nancy

    1984-01-01

    Offers suggestions for activities in which local weeds and wildflowers are used to study a variety of topics. These topics include classification, ecological succession, and mapping. Also lists the types of experiments students can perform with these plants. (JN)

  18. WEEDS IDENTIFICATION USING EVOLUTIONARY ARTIFICIAL INTELLIGENCE ALGORITHM

    OpenAIRE

    2014-01-01

    In a world reached a population of six billion humans increasingly demand it for food, feed with a water shortage and the decline of agricultural land and the deterioration of the climate needs 1.5 billion hectares of agricultural land and in case of failure to combat pests needs about 4 billion hectares. Weeds represent 34% of the whole pests while insects, diseases and the deterioration of agricultural land present the remaining percentage. Weeds Identification has been one of the most inte...

  19. Crop diversity prevents serious weed problems

    DEFF Research Database (Denmark)

    Melander, Bo

    2016-01-01

    Weed management in organic crop production could benefit from more diversification of today’s cropping systems. However, the potential of diversification needs better documentation and solid suggestions for employment in practise must be identified.......Weed management in organic crop production could benefit from more diversification of today’s cropping systems. However, the potential of diversification needs better documentation and solid suggestions for employment in practise must be identified....

  20. Global perspective of herbicide-resistant weeds.

    Science.gov (United States)

    Heap, Ian

    2014-09-01

    Two hundred and twenty weed species have evolved resistance to one or more herbicides, and there are now 404 unique cases (species × site of action) of herbicide-resistant weeds globally. ALS inhibitor-resistant weeds account for about a third of all cases (133/404) and are particularly troublesome in rice and cereals. Although 71 weed species have been identified with triazine resistance, their importance has dwindled with the shift towards Roundup Ready® crops in the USA and the reduction of triazine usage in Europe. Forty-three grasses have evolved resistance to ACCase inhibitors, with the most serious cases being Avena spp., Lolium spp., Phalaris spp., Setaria spp. and Alopecurus myosuroides, infesting more than 25 million hectares of cereal production globally. Of the 24 weed species with glyphosate resistance, 16 have been found in Roundup Ready® cropping systems. Although Conyza canadensis is the most widespread glyphosate-resistant weed, Amaranthus palmeri and Amaranthus tuberculartus are the two most economically important glyphosate-resistant weeds because of the area they infest and the fact that these species have evolved resistance to numerous other herbicide sites of action, leaving growers with few herbicidal options for their control. The agricultural chemical industry has not brought any new herbicides with novel sites of action to market in over 30 years, making growers reliant on using existing herbicides in new ways. In addition, tougher registration and environmental regulations on herbicides have resulted in a loss of some herbicides, particularly in Europe. The lack of novel herbicide chemistries being brought to market combined with the rapid increase in multiple resistance in weeds threatens crop production worldwide. © 2013 Society of Chemical Industry.

  1. Comparative transcriptome analysis of cadmium responses in Solanum nigrum and Solanum torvum.

    Science.gov (United States)

    Xu, Jin; Sun, Jianhang; Du, Liguo; Liu, Xiaojing

    2012-10-01

    Solanum nigrum is a cadmium (Cd) accumulator, whereas Solanum torvum is a low Cd-accumulating plant. The molecular mechanisms that are responsible for differential cadmium (Cd) accumulation in the two Solanum species are poorly understood. • Here, grafting experiments confirmed that increased Cd loading into the root xylem was responsible for the differential Cd accumulation in the two Solanum species. An iron (Fe) supply assay indicated that low Fe accumulation in S. torvum leaves is related to its Cd sensitivity. • Transcriptome analyses revealed higher expression of the genes that encode several metal transporters as well as antioxidant-related genes, and several organic and amino acid biosynthesis/metabolism-related genes in Cd-treated S. nigrum. Our data also indicated that the different responsive mechanisms of the transporter genes to Fe deficiency might be responsible for differential uptake and redistribution of metals in the two Solanum species • These results form a basis upon which to further explore the molecular mechanisms of Cd accumulation and tolerance, and provide an insight into novel strategies that can be used for phytoremediation and food safety.

  2. Effect of different integrated weed management methods on weed density and yield of sugar beet crop

    Directory of Open Access Journals (Sweden)

    alireza koochaki

    2009-06-01

    Full Text Available In order to compare different weed management methods in sugar beet, two experiments were conducted at mashhad for two years in 2005-2006 and 2006-2007. Each experiment designed as a Complete Randomized Block with three replication. The treatments include: Metamitron(Goltix plus Phenmedipham (Betanal (Gol+Bet, Goltix plus Cultivation (Gol+Cu, Disk plus Betanal (Di+Bet, Disk plus Cultivation(Di+Cu, Cover Crop plus Betanal (Co+Bet, Cover Crop plus Cultivation (Co+Cu, Weeding (W and Betanal plus Weeding (Bet+W. Samplings were taken at three stages early season, after imposing the treatments and late season. Results showed that at early season in two experiments, density of weeds was lower in cover crop and disk treatment compared with other treats and the second sampling in first experiment, weeding and disk plus cultivation of treatments with 21.5 and 26.6 respectively plants per m2 and in second experiment year, weeding and application betanal plus weeding treatments, with 14 and 17.8 respectively plant in m2 showed the lowest. In the second experiment year, minimum and maximum sugar beet yield were obtained with cover crop plus betanal and weeding with 43 and 104 ton per hectare respectively. The lowest yield was obtained in check plots with 3.5ton per hectare. Maximum sugar contain (19.35% was obtained in betanal herbicide plus cultivation treatment and minimum (14.88% was obtained with hand weeding treatment. However maximum sugar beet yield was obtained with betanal plus weeding (17.85 ton per hectare and the minimum with cover crop plus betanal (7.5 ton per hectare. Key words: integrated weed management, cover crop, herbicide, cultivation, sugar beet.

  3. Weed Interference Affects Dry Bean Yield and Growth

    Directory of Open Access Journals (Sweden)

    Hossein GHAMARI

    2012-08-01

    Full Text Available Dry bean is one of the most important pulse crops in Iran. Field study was conducted in 2011 to evaluate effects of weed competition from a natural flora on growth and yield of dry bean (Phaseolus vulgaris L.. The treatments consisted of weed infestation and weed removal periods (10, 20, 30, 40 and 50 days after crop emergence. Control plots kept weed-infested and weed-free throughout growing season. To assess the weed competition effect on crop characteristics, Richards, Gompertz and logistic equations were fitted to the data. The most abundant weed species were Chenopodium album and Amaranthus retroflexus. Increase in duration of weed interference decreased the stem height of dry bean. At the end of the growing season, dry bean was 20 cm taller in season-long weed-free treatment compared to the season-long weed-infested treatment. As the number of days of weed interference increased, a declining trend of LAI and number of pods was observed. The minimum number of pods was obtained in season-long weed-infested treatment (5.01 pods/plant. Weed interference during the whole growing season, caused a 60% reduction in yield. Considering 5% and 10% acceptable yield lost, the critical period of weed competition was determined from 20 to 68 and 23 to 55 days after planting (DAE, respectively.

  4. Weed flora of South Africa 1: major groupings

    Directory of Open Access Journals (Sweden)

    M. J. Wells

    1983-12-01

    Full Text Available Whilst attention has been focussed on combating priority weeds we have neglected to obtain an overall picture of our weed flora. To rectify the position a National Weed List has been compiled, the weeds have been classified and an analysis made of the weed flora. Aspects covered in this paper are: major taxa, exotic and indigenous species and kinds of weeds. The presence of imbalances or power shifts between indigenous taxa is indicated by the fact that most weeds are supplied by a few families, and that Monocotyledon species are twice as likely to be weeds as are Dicotyledon species. The preponderance of Monocotyledon weeds is explained by re-invasion of cultivated and abandoned fields in grassland areas rather than by a shift towards Monocotyledon species in the veld. Exotic weeds contribute to imbalances via their greater versatility as well as by re-inforcing some taxa or kind of weed groupings at the expense of others. There is a power shift towards exotic Gymnosperms. Apart from flora weeds, exotics provide most agrestals, lawn weeds and weeds of planted pastures, and nearly as many ruderals as the indigenous species.

  5. Associação de Rhizoctonia solani Grupo de Anastomose 4 (AG-4 HGI e HGIII à espécies de plantas invasoras de área de cultivo de batata Rhizoctonia solani anastomosis group 4 (AG-4 HGI and HGIII associated with weed species from a potato cropping area

    Directory of Open Access Journals (Sweden)

    Fátima Aparecida da Silva-Barreto

    2010-06-01

    tobacco. The AG-4 cause considerable losses in crops of economic importance, such as soybean, beans and peanuts and may also occur in vegetables such as spinach, pepper, broccoli, tomatoes, potatoes and fruit such as melons. The association of R. solani with invasive plants was recently established in potato production areas from Brasília, DF. However, there is no information about the etiology of the pathogen as well as the role of invasive species as alternative hosts in the life cycle of the pathogen. The objective of this study was to characterize isolates of R. solani obtained from potatoes and three other invasive plant species associated with areas of potato production: Shoo-fly plant [Nicandra physaloides (L. Pers., Solanaceae], pigweed (Portulaca oleracea L., Portulacaceae, and low-amaranth (Amaranthus deflexus L., Amaranthaceae. It was confirmed the hypothesis that the R. solani isolates obtained from pigweed, low-amaranth and Shoo-fly plant belong to the anastomosis group 4 and, except for the isolate from pigweed, are pathogenic to potatoes. These isolates were cross pathogencic to all the three weed species tested and also to American nightshade (Solanum americanum Mill., another Solanaceae invasive of potato fields. The placement of the isolates in the group AG-4 HGI or in the group AG-4 HGIII (isolate from caruru was confirmed by cultural and molecular characteristics (sequencing of the ITS-5.8S region of rDNA. The results of this study provide important implications for the management of the Rhizoctonia root rot in potatoes.

  6. Cultivation of Pleurotus ostreatus on weed plants.

    Science.gov (United States)

    Das, Nirmalendu; Mukherjee, Mina

    2007-10-01

    Oyster mushroom, Pleurotus ostreatus (Jacq.:Fr.) Kumm. ITCC 3308 (collected from Indian Type Culture Collection, IARI, New Delhi, India, 110012) was grown on dry weed plants, Leonotis sp, Sida acuta, Parthenium argentatum, Ageratum conyzoides, Cassia sophera, Tephrosia purpurea and Lantana camara. Leonotis sp. was the best substrate in fruit body production of P. ostreatus when it was mixed with rice straw (1:1, wet wt/wet wt) for mushroom cultivation. The fruiting time for P. ostreatus was also less on Leonotis sp. than on any other weed substrates tested in the present investigation. T. purpurea was the least suited weed for oyster mushroom cultivation. The main problem of oyster mushroom cultivation on weed substrates was found to be low yield in the second flush that could be overcome by blending weed plants with rice straw. The protein contents of the fruit bodies obtained from Cassia sophera, Parthenium argentatum and Leonotis sp. were not only better than rice straw but also from the rice straw supplemented weeds.

  7. On weed competition and population dynamics : considerations for crop rotations & organic farming

    NARCIS (Netherlands)

    Mertens, S.K.

    2002-01-01

    Key words: organic farming, weeds, weed management, weed ecology, weed diversity, matrix population model, elasticity analysis, neighbourhood model, survey, crop row spacing, mechanical hoe, harrow, Polygonum convolvulus ,

  8. Molecular and morphological characterisation of Xiphinema americanum group species (Nematoda:Dorylaimida)from California and other regions and co-evolution of bacteria from the genus Candidata Xiphinemobacter with nematodes.

    Science.gov (United States)

    The Xiphinema americanum group is a large species complex containing more than two dozen nematode species. They are economically important because they are vectors of nepoviruses. The species differentiation of X. americanum group is problematic because the species share similar morphological charac...

  9. Developments in physical weed control in Northwest Europe

    Directory of Open Access Journals (Sweden)

    Riemens, Marieen

    2016-02-01

    Full Text Available In North West Europe there is an increasing need for advanced weed control methods. This paper gives an overview of the developments in physical weed control methods. Current innovations in interrow weeding focus on systems that take over the steering function of the driver in order to make them more precise and reduce crop losses. The latest developments in intrarow weeding techniques involve technologies that automatically detect and classify crop and weed plants and use this information to guide a weeding device. Several commercially available examples are presented.

  10. IMPORTANCE OF CRITICAL PERIOD OF WEED COMPETITION FOR CROP GROWING

    OpenAIRE

    Marijana Ivanek-Martinčić; Zvonimir Ostojić; Klara Barić

    2010-01-01

    A concept of critical period of weed competition has been introduced for more than 40 years ago. The concept is based on the assumption that weeds are not equally harmful to a crop during the whole season and that there is a period in crop development in which weeds impact on the yield is the biggest. This period is called critical period of weed competition (CPWC), critical period of weed interference, or critical period of weed control. There is a difference in CPWC between crops, but CPWC ...

  11. Combining a weed traits database with a population dynamics model predicts shifts in weed communities.

    Science.gov (United States)

    Storkey, J; Holst, N; Bøjer, O Q; Bigongiali, F; Bocci, G; Colbach, N; Dorner, Z; Riemens, M M; Sartorato, I; Sønderskov, M; Verschwele, A

    2015-04-01

    A functional approach to predicting shifts in weed floras in response to management or environmental change requires the combination of data on weed traits with analytical frameworks that capture the filtering effect of selection pressures on traits. A weed traits database (WTDB) was designed, populated and analysed, initially using data for 19 common European weeds, to begin to consolidate trait data in a single repository. The initial choice of traits was driven by the requirements of empirical models of weed population dynamics to identify correlations between traits and model parameters. These relationships were used to build a generic model, operating at the level of functional traits, to simulate the impact of increasing herbicide and fertiliser use on virtual weeds along gradients of seed weight and maximum height. The model generated 'fitness contours' (defined as population growth rates) within this trait space in different scenarios, onto which two sets of weed species, defined as common or declining in the UK, were mapped. The effect of increasing inputs on the weed flora was successfully simulated; 77% of common species were predicted to have stable or increasing populations under high fertiliser and herbicide use, in contrast with only 29% of the species that have declined. Future development of the WTDB will aim to increase the number of species covered, incorporate a wider range of traits and analyse intraspecific variability under contrasting management and environments.

  12. Weed seed production, crop planting pattern, and mechanical weeding in wheat

    NARCIS (Netherlands)

    Mertens, S.K.; Jansen, J.

    2002-01-01

    Experiments were carried out to investigate weed seed production in widely spaced spring wheat crops that received aggressive mechanical weed control (hoeing and harrowing) compared with that in narrowly spaced crops receiving less aggressive mechanical control (harrowing only). Three species (wild

  13. Comparative metabolite profiling of Solanum tuberosum against six wild Solanum species with Colorado potato beetle resistance.

    Science.gov (United States)

    Tai, Helen H; Worrall, Kraig; Pelletier, Yvan; De Koeyer, David; Calhoun, Larry A

    2014-09-10

    The Colorado potato beetle Leptinotarsa decemlineata (Say) (CPB) is a coleopteran herbivore that feeds on the foliage on Solanum species, in particular, potato. Six resistant wild Solanum species were identified, and two of these species had low levels of glycoalkaloids. Comparative analysis of the untargeted metabolite profiles of the foliage using UPLC-qTOF-MS was done to find metabolites shared between the wild species but not with Solanum tuberosum (L.) to identify resistance-related metabolites. It was found that only S. tuberosum produced the triose glycoalkaloids solanine and chaconine. Instead, the six wild species produced glycoalkaloids that shared in common tetrose sugar side chains. Additionally, there were non-glycoalkaloid metabolites associated with resistance including hydroxycoumarin and a phenylpropanoid, which were produced in all wild species but not in S. tuberosum.

  14. Lectotypification of Cavanilles' names in Solanum (Solanaceae

    Directory of Open Access Journals (Sweden)

    Knapp, Sandra

    2007-12-01

    Full Text Available Lectotypes are confirmed or designated here for the 13 names coined by Antonio José Cavanilles that were either described, or today are recognised as, members of the large genus Solanum (Solanaceae: Solanum betaceum, S. elaeagnifolium, S. fructotecto, S. lanceolatum, S. lentum, S. parviflorum, S. phyllanthum, S. pinnatum, S. pomiferum, S. pygmaeum, S. triquetrum, Triguera ambrosiaca and T. inodora. A brief introduction assesses the importance of Cavanilles to the botany of his time, and identifies difficulties in lectotypifying names coined by him. The currently accepted name for each taxon is given. Each typification is accompanied by a discussion of the reasoning behind the choice of specimen, and all lectotypes are illustrated.Se confirman o designan los lectótipos de 13 nombres de Antonio José Cavanilles que o bien fueron descritos dentro del género Solanum (Solanaceae o son actualmente reconocidos como parte del mismo: Solanum betaceum, S. elaeagnifolium, S. fructo- tecto, S. lanceolatum, S. lentum, S. parviflorum, S. phyllanthum, S. pinnatum, S. pomiferum, S. pygmaeum, S. triquetrum, Triguera ambrosiaca y T. inodora. Se incluye una breve introducción explicando la importancia de Cavanilles para la botánica de su tiempo, así como las dificultades que entraña lectotipificar las especies de este autor. Se indica el nombre aceptado para cada especie. Las tipificaciones se acompañan de una discusión, explicando la elección de los especímenes. Todos los lectótipos están ilustrados.

  15. AKTIVITAS ANTIFUNGI EKSTRAK DAUN KEMANGI (Ocimum americanum L. TERHADAP FUNGI Fusarium oxysporum Schlecht

    Directory of Open Access Journals (Sweden)

    Zainal Berlian

    2016-01-01

    Full Text Available Fusarium oxysporum Schlecht. a parasitic fungus that cause leaf wilt disease in plants. Meanwhile, basil (Ocimum americanum L. is a plant that contains of the active compound in the form of phenols which have antifungal activity. This study aimed to test whether the extract of leaves of basil have antifungal activity againts Fusarium oxysporum Schlecht. and determine the optimum concentration to inhibit the growth of the fungus Fusarium oxysporum Schlecht. Antifungal test is done by using paper disc diffusion method. The study design used was a completely randomized design with 4 treatments and 6 replications. The treatment is K0 (0% w/v, K1 (5% w/v, K2 (10% w/v, and K3 (15% w/v. The results showed that the leaf extract of basil have antifungal activity against Fusarium oxysporum Schlecht. Inhibition zone on K0, K1, K2, and K3 are each 0,0 mm, 1,49 mm, 2,46 mm, and 2,01 mm. The optimum concentration of antifungal activity of extract of basil, namely the K2 concentration (10% w/v. Based on analysis of variance (ANOVA, the concentration of basil leaf extract provides significant differences (p > 0,05 on fungus Fusarium oxysporum Schlecht., where Fcount > Ftable is 4,5 > 3,1.

  16. Electrophoretically detectable protein variation in natural populations of the lone star tick, Amblyomma americanum (Acari: Ixodidae).

    Science.gov (United States)

    Hilburn, L R; Sattler, P W

    1986-08-01

    Nine populations of Amblyomma americanum (L.) were examined electrophoretically for variation of 21 enzymes. Only three enzymes were not polymorphic and the average heterozygosity per individual (h) for the species was 0.085 with a range of 0.077 to 0.110, comparing well with values in other arthropods. The average Nei identity value for pairwise comparisons among the nine populations was high, 0.994 +/- 0.004 (I +/- SD). These high identity values and the absence of geographic structuring of the protein variation suggest that this species is genetically homogeneous. Normal levels of genic variability within and a lack of divergence between populations were not predicted by models developed to describe these genetic characteristics on the basis of the heterogeneities encountered by parasites in their environment. An analysis of data from several different species of ticks suggests host mobility and abundance, as well as tick abundance and selectivity in choosing a host, are important parameters in determining genetic variation in these ectoparasites.

  17. Geographic distribution and genetic diversity of the Ehrlichia sp. from Panola Mountain in Amblyomma americanum

    Directory of Open Access Journals (Sweden)

    Williamson Phillip C

    2008-04-01

    Full Text Available Abstract Background A novel Ehrlichia, closely related to Ehrlichia ruminantium, was recently discovered from Panola Mountain State Park, GA, USA. We conducted a study to determine if this agent was recently introduced into the United States. Methods We developed a sensitive PCR assay based on the conserved gltA (citrate synthase gene and tested DNA samples extracted from 1964 field-collected and 1835 human-biting Amblyomma americanum from 23 eastern states of the USA. Results The novel agent was detected in 36 ticks collected from 10 states between 1998 and 2006. Infected ticks were collected both from vegetation (n = 14, 0.7% and from humans (n = 22, 1.2%. Fragments of the conserved gltA gene and the variable map1 gene were sequenced from positive samples. Two distinct clades, with 10.5% nucleic acid divergence over the 730 bp map1 sequence, were identified. Conclusion These data suggest that the Panola Mountain Ehrlichia was not recently introduced to the United States; this agent has an extensive distribution throughout the range of its tick vector, has been present in some locations for several years, and displays genetic variability. Furthermore, people in several states were exposed to this agent through the bite of infected ticks, underscoring the potential public health risk of this emerging ehrlichiosis.

  18. Immunofluorescent Localization of Tobacco Ringspot Nepovirus in the Vector Nematode Xiphinema americanum.

    Science.gov (United States)

    Wang, S; Gererich, R C

    1998-09-01

    ABSTRACT An indirect immunofluorescent technique was developed to localize tobacco ringspot nepovirus (TRSV) in the vector nematode Xiphinema americanum sensu stricto. A population of this nematode that efficiently transmitted TRSV was given an acquisition access period of 10 days on TRSV-infected cucumber. Treatment of fragments of viruliferous nematodes with a polyclonal antiserum against TRSV followed by fluorescein isothiocyanate-conjugated goat anti-rabbit immunoglobulin G resulted in virus-specific bright fluorescence only in the lumen of the stylet extension and esophagus. Virus-specific fluorescent signals were observed in the virus-retention region of 44% of the nematode fragments examined. The percentage of nematodes labeled with virus-specific fluorescence increased as the acquisition access period increased from 0 to 22 days; the increase paralleled the increase in the transmission efficiency of the nematode population. Visualization of the entire virus-retention region of individual nematodes within a population of vector or nonvector nematodes provides a rapid and simple means of monitoring specific attachment of plant viruses.

  19. Weed suppression and weed tolerance of wheat cultivars - relevant traits for Integrated Pest Management

    Directory of Open Access Journals (Sweden)

    Verschwele, Arnd

    2014-02-01

    Full Text Available An assortment of 10 winter wheat cultivars was tested for specific effects on weed suppression. Furthermore cultivar specific effects of weed infestation and weed control measures on the crop yield were investigated. Two trial series conducted from 2005 to 2010 demonstrated a wide cultivar specific range of shading capacity and weed suppression. Light penetration and the dry matter of the model weed Sinapis alba were highly correlated (r = 0.87 in trial series A (2005-2007. Consequently, the weed dry matter in the less competitive cultivar Dekan was 5 times higher compared to the weak competitor Cubus. Mechanical weed control by harrowing reduced ears density of all cultivars tested in trial series A. These reductions were significantly higher in the cultivars Bussard and Pegassos compared to the other cultivars. Since the weed infestation was low and negative crop effects by harrowing could be compensated by a higher number of kernels/ear, the yield effects were the same for all cultivars. Contrary to the hypothesis, a cultivar specific yield response by harrowing could not be assessed. Higher competition effects by sowing the model weed Sinapis alba could be realised in trial series B (2008-20120. Consequently, the control measures (a harrowing (b 50% herbicide (c 100% herbicide resulted in significantly higher crop yields ranging from 1.23 t*ha-1 (harrowing to 2.08 t*ha-1 (100% herbicide. The yield reduction caused by the model weed was not the same for all cultivars and was lower for the cultivars Cubus and Limes (6% and 7% compared to Boomer (15%. Thus, weed tolerance could be identified as a cultivar specific trait. There were significant interactions between cultivar and weed control measures: The yield increase (relative to model weed was 5% for Bussard, which was much lower compared to the treatment effects on the cultivar Impression (11%. The hypothesis that yield effects by mechanical and chemical weed control may be affected by the

  20. PHARMACOGNOSTIC STUDY OF KAKAMACHI (SOLANUM NIGRUM LINN

    Directory of Open Access Journals (Sweden)

    Jani Dilip K.

    2012-08-01

    Full Text Available Kakamachi (Solanum nigrum Linn belongs to family Solanaceae and is being used in Ayurveda in skin diseases and diabetes. It is being sold in the market under the common name Makoy. In order to ensure correct botanical standardization to remove the controversy, a detailed pharmacognostic study on whole plant of Solanum nigrum Linn has been carried out. The review on this drug shows that the drug is known since Vedic period. This is the plant amongst the few plants, which are used widely for purposes like Shaka Dravya (Vegetable drug. This study confirms that Solanum nigrum Linn fulfill the standard parameters, decided by the Ayurvedic Pharmacopoeial committee of India. The Physiochemical standards like ash value, alcohol soluble extracts, water soluble extracts etc, were also with the limits of the values mentioned in Pharmacopoeia. The heavy metals analysis of Kakamachi was carried out for Cadmium, Lead, Arsenic, etc., shows that the drug, is free from the abnormal levels of heavy metals. The qualitative study shows the presence of Saponins, Tannins and Alkaloids in Kakamachi. The standard monogram prepared concludes that these parameters could be useful for future standard.

  1. Ecological Intensification Through Pesticide Reduction: Weed Control, Weed Biodiversity and Sustainability in Arable Farming

    Science.gov (United States)

    Petit, Sandrine; Munier-Jolain, Nicolas; Bretagnolle, Vincent; Bockstaller, Christian; Gaba, Sabrina; Cordeau, Stéphane; Lechenet, Martin; Mézière, Delphine; Colbach, Nathalie

    2015-11-01

    Amongst the biodiversity components of agriculture, weeds are an interesting model for exploring management options relying on the principle of ecological intensification in arable farming. Weeds can cause severe crop yield losses, contribute to farmland functional biodiversity and are strongly associated with the generic issue of pesticide use. In this paper, we address the impacts of herbicide reduction following a causal framework starting with herbicide reduction and triggering changes in (i) the management options required to control weeds, (ii) the weed communities and functions they provide and (iii) the overall performance and sustainability of the implemented land management options. The three components of this framework were analysed in a multidisciplinary project that was conducted on 55 experimental and farmer's fields that included conventional, integrated and organic cropping systems. Our results indicate that the reduction of herbicide use is not antagonistic with crop production, provided that alternative practices are put into place. Herbicide reduction and associated land management modified the composition of in-field weed communities and thus the functions of weeds related to biodiversity and production. Through a long-term simulation of weed communities based on alternative (?) cropping systems, some specific management pathways were identified that delivered high biodiversity gains and limited the negative impacts of weeds on crop production. Finally, the multi-criteria assessment of the environmental, economic and societal sustainability of the 55 systems suggests that integrated weed management systems fared better than their conventional and organic counterparts. These outcomes suggest that sustainable management could possibly be achieved through changes in weed management, along a pathway starting with herbicide reduction.

  2. WEED CONTROL IN GENETICALLY MODIFIED GLYPHOSATE-TOLERANT SOYBEAN MANEJO DE PLANTAS DANINHAS EM SOJA GENETICAMENTE MODIFICADA TOLERANTE AO GLYPHOSATE

    Directory of Open Access Journals (Sweden)

    Júlio Cezar Durigan

    2011-04-01

    Full Text Available The transgenic production systems, as well as conventional systems, require, in addition to chemical control, the adoption of other weed management strategies. This study was developed to evaluate the weed chemical control in glyphosate tolerant soybean, associated to cover crops cultivated in the autumn/winter. The experiment was carried out under field conditions at the FCAV/Unesp, Jaboticabal, São Paulo State, Brazil. A randomized split-plot block design was used, with four replications. St. Lucia Grass (Brachiaria brizantha ‘Marandu’, forage millet (Pennisetum americanum ‘BN2’, and a treatment with spontaneous growth vegetation were evaluated for plots, and, for subplots, the herbicides glyphosate, chlorimuron - ethyl plus lactofen, and fluazifop-p-butyl, in a sequential spraying, and two controls without any application. Grass cover contributed to the chemical control, suppressing weeds, and the single application of 720 g a.e. ha-1 of glyphosate, independently of the cover crop cultivated in the autumn/winter, was sufficient for adequately controlling Acanthospermum hispidum, Alternanthera tenella, Amaranthus sp., Bidens pilosa, Xanthium strumarium, Cenchrus echinatus, Digitaria sp., and Eleusine indica, with results similar to the treatment (chlorimuron-ethyl + lactofen + fluazifop-p-buthyl. When compared to the weeded control, the herbicides did not affect plants height, dry matter of the aerial parts, mass of 100 grains, and grain yield. Soybean plants grown over St. Lucia Grass and forage millet presented a higher height, however, no other feature was influenced by the cover crop.

    KEY-WORDS: Brachiaria brizantha; Pennisetum americanum; no-tillage; Roundup Ready; spontaneous vegetation.

    Os sistemas de produção transgênicos, assim como os

  3. Participatory development of weed management technologies in Benin

    NARCIS (Netherlands)

    Vissoh, P.V.

    2006-01-01

    Keywords: permanent land use, weeds, indigenous knowledge, integrated crop and soil management, participatory learning, co-researchWeeds constitute a major constraint to agricultural production in the Republic of Benin. Agricultural intensification and the evolution towards permanent cropping system

  4. Participatory development of weed management technologies in Benin

    NARCIS (Netherlands)

    Vissoh, P.V.

    2006-01-01

    Keywords: permanent land use, weeds, indigenous knowledge, integrated crop and soil management, participatory learning, co-researchWeeds constitute a major constraint to agricultural production in the Republic of Benin. Agricultural intensification and the evolution towards permanent cropping

  5. Effectiveness of the Primextra Gold in controlling weeds of ...

    African Journals Online (AJOL)

    Effectiveness of the Primextra Gold in controlling weeds of Cucumber ( Cucumis Sativus L. ) ... Journal of Applied Sciences and Environmental Management ... The efficacy of Primextra Gold herbicide in controlling weeds in cucumber was ...

  6. Application of Machine Vision Technique in Weed Identification

    Institute of Scientific and Technical Information of China (English)

    LIU Zhen-heng; ZHANG Chang-li; FANG Jun-long

    2004-01-01

    This paper mainly introduces some foreign research methods and fruits about weed identification by applying machine vision. This facet researches is lack in our country, this paper could be reference for domestic studies about weed identification.

  7. 220 213 Effects of Weeds on the Profitabili

    African Journals Online (AJOL)

    2008-12-02

    Dec 2, 2008 ... Groundnut (Arachis hypogaea) Crops in Mixed Cropping Systems. 1A.T. Yahaya, 1K.M. Baba, 1U. ... outweighed any possible benefit associated with weeds. ..... for weed control such as crop rotation and cover cropping.

  8. Participatory development of weed management technologies in Benin

    NARCIS (Netherlands)

    Vissoh, P.V.

    2006-01-01

    Keywords: permanent land use, weeds, indigenous knowledge, integrated crop and soil management, participatory learning, co-researchWeeds constitute a major constraint to agricultural production in the Republic of Benin. Agricultural intensification and the evolution towards permanent cropping system

  9. Exploring cost-effective maize integrated weed management ...

    African Journals Online (AJOL)

    Exploring cost-effective maize integrated weed management approaches under intensive farming systems. ... Log in or Register to get access to full text downloads. ... Kamuliand Iganga districts with one hand-hoe weeding (1hh) as the control.

  10. Image-based thresholds for weeds in maize fields

    DEFF Research Database (Denmark)

    Asif, Ali; Streibig, Jens Carl; Christensen, Svend

    2015-01-01

    Recent development of site-specific weed management strategies suggests patch application of herbicides to avoid their excessive use in crops. The estimation of infestation of weeds and control thresholds are important components for taking spray decisions. If weed pressure is below a certain level...... in some parts of the field and if late germinating weeds do not affect yield, it may not be necessary the spray such places from an economic point of view. Consequently, it makes sense to develop weed control thresholds for patch spraying, based on weed cover early in the growing season. In Danish maize...... field experiments conducted from 2010 to 2012, we estimated competitive ability parameters and control thresholds of naturally established weed populations in the context of decision-making for patch spraying. The most frequent weed was Chenopodium album, accompanied by Capsella bursa-pastoris, Cirsium...

  11. Weeds as important vegetables for farmers

    Directory of Open Access Journals (Sweden)

    Gisella S. Cruz-Garcia

    2012-12-01

    Full Text Available The objective of this study was to investigate the multiple uses and cognitive importance of edible weeds in Northeast Thailand. Research methods included focus group discussions and freelistings. A total of 43 weeds consumed as vegetable were reported, including economic, naturalized, agricultural and environmental weeds. The weedy vegetables varied considerably on edible parts, presenting both reproductive (flowers, fruits and seeds and vegetative organs (shoots, leaves, flower stalks, stems or the whole aerial part. The results of this study show that weedy vegetables are an important resource for rice farmers in this region, not only as a food but also because of the multiple additional uses they have, especially as medicine. The fact that the highest Cognitive Salience Index (CSI scores of all wild vegetables freelisted corresponded to weeds, reinforces the assertion that weeds are culturally cognitively important for local farmers as a vegetable source. This is a key finding, given that these species are targets of common pesticides used in this region.

  12. An ultrasonic system for weed detection in cereal crops.

    Science.gov (United States)

    Andújar, Dionisio; Weis, Martin; Gerhards, Roland

    2012-12-13

    Site-specific weed management requires sensing of the actual weed infestation levels in agricultural fields to adapt the management accordingly. However, sophisticated sensor systems are not yet in wider practical use, since they are not easily available for the farmers and their handling as well as the management practice requires additional efforts. A new sensor-based weed detection method is presented in this paper and its applicability to cereal crops is evaluated. An ultrasonic distance sensor for the determination of plant heights was used for weed detection. It was hypothesised that the weed infested zones have a higher amount of biomass than non-infested areas and that this can be determined by plant height measurements. Ultrasonic distance measurements were taken in a winter wheat field infested by grass weeds and broad-leaved weeds. A total of 80 and 40 circular-shaped samples of different weed densities and compositions were assessed at two different dates. The sensor was pointed directly to the ground for height determination. In the following, weeds were counted and then removed from the sample locations. Grass weeds and broad-leaved weeds were separately removed. Differences between weed infested and weed-free measurements were determined. Dry-matter of weeds and crop was assessed and evaluated together with the sensor measurements. RGB images were taken prior and after weed removal to determine the coverage percentages of weeds and crop per sampling point. Image processing steps included EGI (excess green index) computation and thresholding to separate plants and background. The relationship between ultrasonic readings and the corresponding coverage of the crop and weeds were assessed using multiple regression analysis. Results revealed a height difference between infested and non-infested sample locations. Density and biomass of weeds present in the sample influenced the ultrasonic readings. The possibilities of weed group discrimination were

  13. An Ultrasonic System for Weed Detection in Cereal Crops

    Directory of Open Access Journals (Sweden)

    Dionisio Andújar

    2012-12-01

    Full Text Available Site-specific weed management requires sensing of the actual weed infestation levels in agricultural fields to adapt the management accordingly. However, sophisticated sensor systems are not yet in wider practical use, since they are not easily available for the farmers and their handling as well as the management practice requires additional efforts. A new sensor-based weed detection method is presented in this paper and its applicability to cereal crops is evaluated. An ultrasonic distance sensor for the determination of plant heights was used for weed detection. It was hypothesised that the weed infested zones have a higher amount of biomass than non-infested areas and that this can be determined by plant height measurements. Ultrasonic distance measurements were taken in a winter wheat field infested by grass weeds and broad-leaved weeds. A total of 80 and 40 circular-shaped samples of different weed densities and compositions were assessed at two different dates. The sensor was pointed directly to the ground for height determination. In the following, weeds were counted and then removed from the sample locations. Grass weeds and broad-leaved weeds were separately removed. Differences between weed infested and weed-free measurements were determined. Dry-matter of weeds and crop was assessed and evaluated together with the sensor measurements. RGB images were taken prior and after weed removal to determine the coverage percentages of weeds and crop per sampling point. Image processing steps included EGI (excess green index computation and thresholding to separate plants and background. The relationship between ultrasonic readings and the corresponding coverage of the crop and weeds were assessed using multiple regression analysis. Results revealed a height difference between infested and non-infested sample locations. Density and biomass of weeds present in the sample influenced the ultrasonic readings. The possibilities of weed group

  14. Antioxidant glucosylated caffeoylquinic acid derivatives in the invasive tropical soda apple, Solanum viarum

    Science.gov (United States)

    The eggplant (Solanum melongena) and other species within the “spiny solanums” (Solanum subgenus Leptostemonum) contain diverse and abundant antioxidant caffeoylquinic acid (CQA) derivatives. The fruit of an aggressive invasive species in the spiny solanums, Solanum viarum, contain numerous CQA deri...

  15. Genetic diversity of the African hexaploid species Solanum scabrum Mill. and S. nigrum L. (Solanaceae)

    NARCIS (Netherlands)

    Manoko, M.L.K.; Berg, van den R.G.; Feron, R.M.C.; Weerden, van der G.M.; Mariani, C.

    2008-01-01

    Two hexaploid species of Solanum sect. Solanum are present in Africa: Solanum scabrum and S. nigrum. Solanum scabrum is a widely cultivated species and is used as a leafy vegetable, as a source of medicine and as a source of ink dye. In previous studies a wide range of morphological diversity has be

  16. The variability of leaf anatomical characteristics of Solanum nigrum L. (Solana-les, Solanaceae from different habitats

    Directory of Open Access Journals (Sweden)

    Krstić Lana N.

    2002-01-01

    Full Text Available In Europe on the whole as well as in Yugoslavia, the most widespread weed species from the genus Solanum is Solanum nigrum L. Since this species inhabits different habitats, it developed several ways of adaptation to environmental conditions. The influence of ecological factors on plant organism and resulting plant adaptations are most evident in leaf morphology and anatomy. Therefore, the anatomical structure of leaves and leaf epidermal tissue of S. nigrum was analyzed and compared among plants that originated from different habitats, in order to determine leaf structural adaptations. S. nigrum lamina has the mesomorphic structure with some xero-heliomorphic adaptations. The differences in stomata number, number of hairs, thickness of lamina, palisade and spongy tissue, as well as the size of mesophyll cells have been noticed. The highest values for most of the parameters have been recorded for the plants from cultivated soil. Largest variations of the examined characters were found for the leaves from ruderal habitats, where environmental conditions are most variable.

  17. Importance of herbicide resistance in weeds of natural areas

    OpenAIRE

    DiTomaso, Joseph

    2014-01-01

    Worldwide, the majority of the plant species that are developing herbicide resistance are those that occur as weeds in agricultural environments, on roadsides and in other rights-of-way. In contrast, herbicide resistance is not nearly so common in weeds of natural areas or rangelands. A search of the International Survey of Herbicide Resistant Weeds ( weedscience.com ) revealed no herbicide-resistant weeds (i.e., invasive nonnative species) listed for terrestrial natural areas anywhere in the...

  18. The weeds of abandoned cotton fields in Mozambique

    Directory of Open Access Journals (Sweden)

    A. A. Balsinhas

    1983-12-01

    Full Text Available Based on a botanical survey of Chibuto, Chemba, Namapa, Nampula and Mutuali, a table of 120 of the most common weeds of cotton and fallow fields in Mozambique is presented. After considering the factors which affect the flora of these zones, the successional weed vegetation is described and the principal species are enumerated. Finally, the dangers of infestation (shrubby weeds in alluvial zones and the utilization of the weed flora in other zones of the country are described.

  19. PLANT SPACING AND WEED MANAGEMENT TECHNIQUES INFLUENCE WEED COMPETITIVENESS OF DRUM SEEDED RICE (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    B N Sandeep Nayak

    2014-11-01

    Full Text Available Direct wet seeded-rice sown through drum seeder, a potential wise rice production system in the present-day scenario, is subject to severe weed infestation and, therefore, development of a sustainable weed management strategy is crucial for its wide spread adoption. The present study was conducted in kharif 2012 at department of agronomy division with NLR-33358 (SOMASILA using six planting densities under five weed management conditions. The plant spacing tried were: 20cm x 7cm, 20 cm x 10.5 cm, 20 cm x 14 cm, 20 cm x 17.5 cm and 20 cm x 24.5cm and 20 cm x15cm. with a plant density of 71, 47, 35, 28, 20 and 33 hills m-2, respectively and five weed management practices viz., weedy check (W1, hand weeding at 20 and 40 DAS (W2, cono weeding at 20 and 40 with modified cono weeder (W3, pre-emergence application of anilofos @ 0.375 kg a.i ha-1 followed by post-emergence application of 2, 4 D sodium salt @ 1.0 kg a.i ha-1 20-25 DAS (W4, pre-emergence application of pendimethalin @1.0 kg a.i ha-1 followed by post-emergence application of bispyribac sodium @ 20 g a.i ha-1 30 DAS ( W5. . The experiment was laid out in strip- plot design with three replications assigning weed management techniques in vertical factor and plant spacing in horizontal factor. Direct wet seeded rice field was infested with 12 and 22 weed species, kharif -2012 season having Echinochloa colona, Leptochloa chinensis, Digitaria aescendens, Cyperus iriaand Eleusine indicaas the predominant weeds. Rice spacing exerted significant influence on both weed pressure and yield performance of crop. With the increase in plant spacing weed dry matter decreased but rice yield increased. In this season, among different plant densities, the highest density of 71 hills m-2(D1 resulted in minimum weed density, weed drymatter, and more number of tillers m-2 and maximum drymatter production at all stages of plant growth. closest spacing resulted in maximum weed suppression, but among various rice

  20. Conservation and aquaculture of native freshwater prawns: the case of the cauque river prawn Macrobrachium americanum (Bate, 1868

    Directory of Open Access Journals (Sweden)

    Marcelo García-Guerrero

    2015-11-01

    Full Text Available Latin America has a high diversity of Macrobrachium prawns, some of them with commercial interest. Among them, the cauque river prawn Macrobrachium americanum is a large prawn of the western coast with commercial value due to its size and taste, but it has been extensively subjected to fishery exploitation, leading to population decline. Cultivation is an option for commercial production and conservation. Some research focused on domestication has been performed. Here, we revise the status of that research and discuss possibilities for sustainable freshwater prawn aquaculture in Mexico and elsewhere in Latin America.

  1. Resistance to Phytophthora infestans in Solanum tuberosum and wild Solanum species

    NARCIS (Netherlands)

    Colon, L.T.

    1994-01-01

    Resistance to Phytophthora infestans , the causal agent of late blight, is present in the potato, Solanum tuberosum , and in many wild relatives of this crop. The resistance of S. tuberosum is partial and, though helpful in reducing the use of fungicides, is not sufficient to fully solve the problem

  2. Cover crop-based ecological weed management: exploration and optimization

    NARCIS (Netherlands)

    Kruidhof, H.M.

    2008-01-01

    Keywords: organic farming, ecologically-based weed management, cover crops, green manure, allelopathy, Secale cereale, Brassica napus, Medicago sativa Cover crop-based ecological weed management: exploration and optimization. In organic farming systems, weed control is recognized as one of the mai

  3. Focus on ecological weed management : what is hindering adoption?

    NARCIS (Netherlands)

    Bastiaans, L.; Paolini, R.; Baumann, D.T.

    2008-01-01

    Despite increased concerns regarding the heavy reliance of many cropping systems on chemical weed control, adoption of ecological weed management practices is only steadily progressing. For this reason, this paper reflects on both the possibilities and limitations of cultural weed control practices.

  4. 75 FR 68945 - Update of Noxious Weed Regulations

    Science.gov (United States)

    2010-11-10

    ... Noxious Weed Regulations AGENCY: Animal and Plant Health Inspection Service, USDA. ACTION: Final rule... ] weeds by adding definitions of terms used in the regulations, adding details regarding the process of applying for the permits used to import or move noxious weeds, adding a requirement for the treatment of...

  5. 7 CFR 361.6 - Noxious weed seeds.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Noxious weed seeds. 361.6 Section 361.6 Agriculture..., DEPARTMENT OF AGRICULTURE IMPORTATION OF SEED AND SCREENINGS UNDER THE FEDERAL SEED ACT § 361.6 Noxious weed... considered noxious weed seeds. (1) Seeds with no tolerances applicable to their introduction: Aeginetia spp...

  6. A century of progress in weed control in hardwood seedbeds

    Science.gov (United States)

    David B. South

    2009-01-01

    Weeds have existed in nurseries since before the time Bartram grew hardwoods during the 18th century. Hand weeding was the primary method of weed control during the first part of the 20th century. From 1931 to 1970, advances in chemistry increased the use of herbicides, and advances in engineering increased the reliance on machines for cultivation. Many managers now...

  7. 7 CFR 201.52 - Noxious-weed seeds.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Noxious-weed seeds. 201.52 Section 201.52 Agriculture... REGULATIONS Purity Analysis in the Administration of the Act § 201.52 Noxious-weed seeds. (a) The determination of the number of seeds, bulblets, or tubers of individual noxious weeds present per unit weight...

  8. Evaluation of UAV imagery for mapping Silybum marianum weed patches

    Science.gov (United States)

    The invasive weed, milk thistle (Silybum marianum), has the tendency to grow in patches. In order to perform site-specific weed management, determining the spatial distribution of weeds is important for its eradication. Remote sensing has been used to perform species discrimination, and it offers pr...

  9. Weed control through seedling abrasion with an organic fertilizer

    Science.gov (United States)

    Many tools exist to control weeds in organic crops, and each has utility in specific situations. Nevertheless, surveys of organic farmers indicate that weed management often is second only to labor supply as their main bottleneck for success. Consequently, new tactics for managing weeds are desirabl...

  10. Weed management in banana production: The use of Nelsonia ...

    African Journals Online (AJOL)

    EJIRO

    reduced in banana grown with N. canescens cover crop than in plants grown without. ... benefiting the soil and other crops (SAN, 1996; Creamer ... canopy that is more competitive than weeds for light, ... suppress weeds, to what extent it affects banana yield as .... time taken in weeding plots with cover crop was about a.

  11. Weed supression by smother crops and selective herbicides

    Directory of Open Access Journals (Sweden)

    Severino Francisco José

    2004-01-01

    Full Text Available Using a smother crop is thought to suppress weed density and to add other beneficial effects in sustainable agricultural systems. Weed suppression ought to be considered an essential component of integrated weed management. However, very little is known about the effects of green manure plants on weeds. This study evaluated the influence of three green manure species on weed suppression and selectivity of herbicides. A field experiment was designed to determine the effect of the green manure species Crotalaria juncea, Arachis pintoi and pigeon pea on the weeds Brachiaria decumbens, guineagrass and hairy beggarticks, and on the natural weed infestation in the inter rows area of an avocado orchard. The weed species were suppressed differently by each green manure species. Soil samples collected from the field experiment presented a residual effect, of at least 30 d, in suppressing weed seed bank recruitment; this residual effect was caused by the residues of the green manure present in the soil. When the green manure was incorporated into the top 5 cm of soil or left on the surface, in a greenhouse experiment, the emergence of weed seeds was significantly inhibited, depending on the species, and on the amount and depth of green manure incorporation. Greenhouse experiments indicate that pre-emergence herbicides cause lower phytotoxicity than post-emergence Arachis pintoi. Smother crops using green manure species, when well established in an area, provide additional weed control to the cropping system and are effective and valuable tools in integrated weed management.

  12. Onion and weed response to mustard (Sinapis alba) seed meal

    Science.gov (United States)

    Weed control in organic onion production is often difficult and expensive, requiring numerous cultivations and extensive hand-weeding. Onion safety and weed control with mustard seed meal (MSM) derived from Sinapis alba was evaluated in greenhouse and field trials. MSM applied at 110, 220, and 440 g...

  13. Developments in physical weed control in Northwest Europe

    NARCIS (Netherlands)

    Riemens, M.M.

    2016-01-01

    In North West Europe there is an increasing need for advanced weed control methods. This paper gives an overview of the developments in physical weed control methods. Current innovations in interrow weeding focus on systems that take over the steering function of the driver in order to make them mor

  14. Critical period of weed control In cumin (Cuminum cyminum

    Directory of Open Access Journals (Sweden)

    azade hoseyni

    2009-06-01

    Full Text Available In order to evaluate the critical period of weed control in Cumin, an experiment with Complete Randomized Block Design and three replications was conducted in experimental field of Faculty of Agriculture, Ferdowsi University of Mashhad, During 2004-2005 growing season. Treatments included different combinations of weed free and weed infested periods (20, 30, 40 and 80 days after germination plus weedy check and weed free check. Critical period weed control was evaluated with Gompertz and Logestic functions. Traits measured were yield and yield components, harvest index of cumin and also number and weight of weed species. Results showed the critical period was between 24-38 days after germination. With increasing interfereing period at early or late growth stages of cumin, the economic yield was reduced. By extending weeding periods at early stage of growth or during the growth period, dry weight of weeds were reduced, while extending weeding period at the end of growth stage and also weed free during growth period, early or late stages of growth had no significant effects on yield components except on number of umbels per plant. Harvest index was positively affected by early weeding. It appears that early weeding was somehow more effective on yield components for cumin.

  15. CRITICAL PERIOD OF MUNGBEAN (PHASEOLUS RADIATUS L. TO WEED COMPETITION

    Directory of Open Access Journals (Sweden)

    I.H. UTOMO*

    1989-01-01

    Full Text Available A field experiment was conducted to study the critical period of weed control on the crop of mungbean (Phaseolus radiatus L.. The studies were done in the field of BIOTROP Experimental Station with the natural existing weed population. It was found that the critical period of mungbean to weed competition was from 3-6 weeks after planting.

  16. CRITICAL PERIOD OF MUNGBEAN (PHASEOLUS RADIATUS L.) TO WEED COMPETITION

    OpenAIRE

    I.H. UTOMO*

    1989-01-01

    A field experiment was conducted to study the critical period of weed control on the crop of mungbean (Phaseolus radiatus L.). The studies were done in the field of BIOTROP Experimental Station with the natural existing weed population. It was found that the critical period of mungbean to weed competition was from 3-6 weeks after planting.

  17. Herbicide-resistant weeds: Management strategies and upcoming technologies

    Science.gov (United States)

    Herbicides have contributed to substantial increase in crop yields over the past seven decades. Over reliance on herbicides for weed control has led to rapid evolution of herbicide-resistant (HR) weeds. Increased awareness of herbicide resistance and adoption of diversified weed control tactics by f...

  18. The role of arable weed seeds for agroecosystem functioning

    NARCIS (Netherlands)

    Franke, A.C.; Lotz, L.A.P.; Burg, van der W.J.; Overbeek, van L.S.

    2009-01-01

    A literature study was conducted to gather knowledge on the impact of weed seeds on agroecosystem functioning other than effects related to the production of weed seedlings and plants. The results of the review suggested that a larger and more diverse weed seedbank can contribute to the biodiversity

  19. 7 CFR 360.200 - Designation of noxious weeds.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Designation of noxious weeds. 360.200 Section 360.200... SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.200 Designation of noxious weeds. As... determined that the following plants 1 or plant products fall within the definition of “noxious weed” as...

  20. Pest Control in Corn and Soybeans: Weeds - Insects - Diseases.

    Science.gov (United States)

    Doersch, R. E.; And Others

    This document gives the characteristics and application rates for herbicides used to control annual weeds in corn, annual and perennial broadleaf weeds in corn, quackgrass and yellow nutsedge in corn, and annual weeds in soybeans. It also gives insecticide use information for corn and soybeans. A brief discussion of disease control in corn and…

  1. Cover crop-based ecological weed management: exploration and optimization

    NARCIS (Netherlands)

    Kruidhof, H.M.

    2008-01-01

    Keywords: organic farming, ecologically-based weed management, cover crops, green manure, allelopathy, Secale cereale, Brassica napus, Medicago sativa Cover crop-based ecological weed management: exploration and optimization. In organic farming systems, weed control is recognized as one of the

  2. RNA-seq discovery, functional characterization, and comparison of sesquiterpene synthases from Solanum lycopersicum and Solanum habrochaites trichomes

    NARCIS (Netherlands)

    Bleeker, P.M.; Spyropoulou, E.A.; Diergaarde, P.J.; Volpin, P.; de Both, M.T.J.; Zerbe, P.; Bohlmann, J.; Falara, V.; Matsuba, Y.; Pichersky, E.; Haring, M.A.; Schuurink, R.C.

    2011-01-01

    Solanum lycopersicum and Solanum habrochaites (f. typicum) accession PI127826 emit a variety of sesquiterpenes. To identify terpene synthases involved in the production of these volatile sesquiterpenes, we used massive parallel pyrosequencing (RNA-seq) to obtain the transcriptome of the stem

  3. Checklist for the crop weeds of Paraguay

    Directory of Open Access Journals (Sweden)

    Juana De Egea

    2016-10-01

    Full Text Available Paraguay, a country whose economy is based mainly on agriculture and livestock for export, has experienced a major expansion in mechanized crops during the last few decades. Despite being heavily dependent on agriculture, Paraguay has very limited research on crop weeds, in spite of these having a high economic impact on production. This work aims to update and enhance the knowledgebase on the most common weeds affecting productive fields throughout the different ecoregions of Paraguay. We present here the first checklist of crop weeds for the country, which includes a total of 256 taxa (189 species, 10 subspecies, 54 varieties and 3 forms, with the most species-rich families being Poaceae and Asteraceae followed by Malvaceae, Amaranthaceae, Fabaceae and Solanaceae. The list includes three new records for the country. Synonyms, distribution details within Paraguay, habit and a voucher specimen are provided for each taxon.

  4. Aqueous pesticide mitigation efficiency of Typha latifolia (L.), Leersia oryzoides (L.) Sw., and Sparganium americanum Nutt.

    Science.gov (United States)

    Moore, Matthew T; Tyler, Heather L; Locke, Martin A

    2013-08-01

    Agricultural pesticide use is necessary to help meet the increased demand for a safe and secure food supply for the United States, as well as the global community. Even with proper application and careful management, the possibility of pesticide leaching and detachment in runoff still exists following certain storm events. Several different management practices have been designed to reduce the impacts of pesticides on aquatic receiving systems. Many such practices focus on the use of vegetation to slow runoff and allow for sorption of the various contaminants. Three common drainage ditch macrophytes, Leersia oryzoides (cutgrass), Typha latifolia (cattail), and Sparganium americanum (bur-reed) were assessed for their ability to reduce effluent loads of atrazine, diazinon, and permethrin in simulated agricultural runoff water in 379L individual mesocosms. Of the three macrophytes examined, L. oryzoides was the most effective at mitigating atrazine, and permethrin. L. oryzoides and T. latifolia significantly reduced overall atrazine loads (45±7%, p=0.0073 and 35±8%, p=0.0421, respectively) when compared to unvegetated controls (13±20%). No significant differences in overall diazinon load retention were noted between plant species. Each plant species significantly decreased the initial load (after 6h) of trans-permethrin, while both L. oryzoides and T. latifolia significantly reduced the overall trans-permethrin loads (88±5%, p=0.0022 and 88±5%, p=0.0020, respectively) when compared to unvegetated controls (68±8%). Reversible adsorption of atrazine and diazinon to plants, noted during the flushing events, was greater than that observed in either cis- or trans-permethrin. These results demonstrate the ability of native ditch vegetation to mitigate pesticides associated with agricultural runoff. Likewise, they provide farmers and action agencies with supportive data for selection of vegetation in drainage ditches used as management practices. Published by Elsevier

  5. Isolation of Tacaribe virus, a Caribbean arenavirus, from host-seeking Amblyomma americanum ticks in Florida.

    Directory of Open Access Journals (Sweden)

    Katherine A Sayler

    Full Text Available Arenaviridae are a family of single stranded RNA viruses of mammals and boid snakes. Twenty-nine distinct mammalian arenaviruses have been identified, many of which cause severe hemorrhagic disease in humans, particularly in parts of sub-Saharan Africa, and in Central and South America. Humans typically become infected with an arenavirus through contact with excreta from infected rodents. Tacaribe virus (TCRV is an arenavirus that was first isolated from bats and mosquitoes during a rabies surveillance survey conducted in Trinidad from 1956 to 1958. Tacaribe virus is unusual because it has never been associated with a rodent host and since that one time isolation, the virus has not been isolated from any vertebrate or invertebrate hosts. We report the re-isolation of the virus from a pool of 100 host-seeking Amblyomma americanum (lone star ticks collected in a Florida state park in 2012. TCRV was isolated in two cell lines and its complete genome was sequenced. The tick-derived isolate is nearly identical to the only remaining isolate from Trinidad (TRVL-11573, with 99.6% nucleotide identity across the genome. A quantitative RT-PCR assay was developed to test for viral RNA in host-seeking ticks collected from 3 Florida state parks. Virus RNA was detected in 56/500 (11.2% of surveyed ticks. As this virus was isolated from ticks that parasitize humans, the ability of the tick to transmit the virus to people should be evaluated. Furthermore, reservoir hosts for the virus need to be identified in order to develop risk assessment models of human infection.

  6. Isolation of Tacaribe virus, a Caribbean arenavirus, from host-seeking Amblyomma americanum ticks in Florida.

    Science.gov (United States)

    Sayler, Katherine A; Barbet, Anthony F; Chamberlain, Casey; Clapp, William L; Alleman, Rick; Loeb, Julia C; Lednicky, John A

    2014-01-01

    Arenaviridae are a family of single stranded RNA viruses of mammals and boid snakes. Twenty-nine distinct mammalian arenaviruses have been identified, many of which cause severe hemorrhagic disease in humans, particularly in parts of sub-Saharan Africa, and in Central and South America. Humans typically become infected with an arenavirus through contact with excreta from infected rodents. Tacaribe virus (TCRV) is an arenavirus that was first isolated from bats and mosquitoes during a rabies surveillance survey conducted in Trinidad from 1956 to 1958. Tacaribe virus is unusual because it has never been associated with a rodent host and since that one time isolation, the virus has not been isolated from any vertebrate or invertebrate hosts. We report the re-isolation of the virus from a pool of 100 host-seeking Amblyomma americanum (lone star ticks) collected in a Florida state park in 2012. TCRV was isolated in two cell lines and its complete genome was sequenced. The tick-derived isolate is nearly identical to the only remaining isolate from Trinidad (TRVL-11573), with 99.6% nucleotide identity across the genome. A quantitative RT-PCR assay was developed to test for viral RNA in host-seeking ticks collected from 3 Florida state parks. Virus RNA was detected in 56/500 (11.2%) of surveyed ticks. As this virus was isolated from ticks that parasitize humans, the ability of the tick to transmit the virus to people should be evaluated. Furthermore, reservoir hosts for the virus need to be identified in order to develop risk assessment models of human infection.

  7. Solanum nigrum L. as a Hepatoprotective Agent

    Directory of Open Access Journals (Sweden)

    Muthiana Rizky

    2015-03-01

    Full Text Available Background: Liver damage may be caused by various factors. Solanum nigrum L. fruit is known to contain flavonoid antioxidant which is responsible for its hepatoprotective effect. A study was conducted to determine the protective effect of Solanum nigrum L. fruit infusion (SNFI on CCl4-induced hepatic cell damage in rats. Methods: A complete randomized experimental study was conducted on 25 male Wistar strain-white rats (Rattusnorvegicus which were divided into five groups during the period of September– October 2012. Group I (negative control was given standardized food and water; group II (positive control was induced by carbon tetrachloride (CCl4 10% paraffin intraperitoneally by 8 mL/kg body weight on the 8th day of the study; group III, IV, V (treated were given Solanum nigrum L. fruit infusion (SNFI by 22.5g/100mL, 45 g/100mL and 90g/100mL concentrations for 8 days, respectively, prior to CCl4 induction. The calculation of necrotic liver cells was performed in 48 hours after induction. Data were statistically analyzed using Kruskal-Wallis test followed by Mann-Whitney post-hoc test. Results: The percentage of necrosis liver cells in group III, IV, and V was smaller compared to the positive control group. The protective effect of SNFI against CCl4-induced hepatotoxicity may be related to its ability to elevate the antioxidant agent in the body. There were significant differences in necrotic between Group II and group III, IV, V which were treated with SNFI. Conclusion: Further investigation is required to characterize the active ingredients and the mechanism of SNF action to confirm the hepatoprotective and antioxidant effects.

  8. BIOLOGICAL CONTROL OF WEEDS BY MEANS OF PLANT PATHOGENS

    Directory of Open Access Journals (Sweden)

    Marija Ravlić

    2014-06-01

    Full Text Available Biological control is the use of live beneficial organisms and products of their metabolism in the pests control. Plant pathogens can be used for weed control in three different ways: as classical, conservation and augmentative (inoculative and inundated biological control. Inundated biological control involves the use of bioherbicides (mycoherbicides or artificial breeding of pathogens and application in specific stages of crops and weeds. Biological control of weeds can be used where chemical herbicides are not allowed, if resistant weed species are present or in the integrated pest management against weeds with reduced herbicides doses and other non-chemical measures, but it has certain limitations and disadvantages.

  9. Uji Aktivitas Anti-Inflamasi Minyak Atsiri Daun Kemangi (Ocimum americanum L. pada Tikus Putih Jantan yang Diinduksi Karagenan

    Directory of Open Access Journals (Sweden)

    Fadlina Chany Saputri

    2016-12-01

    Full Text Available Kemangi (Ocimum americanum L. is an aromatic plant that contains citral and known as anti-inflammatory agents. The aimed of this study was to determine the anti-inflammatory activity of the essential oil kemangi leaves on carrageenan-induced rat. The male rats were divided into six groups, each consisting of four rats. Group I as negative control was given 0.5% CMC solution, group II as positive control was given diclofenac sodium, group III was given sitral, groups IV, V and VI were given 40 mg/200 g BW, 80 mg/200 g BW, and 160 mg/200 g BW essential oil of Ocimum americanum L., emulsified in 0.5% CMC solution. After 30 minutes of administration, left paw of rats was injected bycarragenan 0.2 mL to induce edema. Edema volume was measured using pletismometer every hour for six hours. The result showed that at dose 160 mg/200 g BW gives the best effect in inhibited the inflamation response 44,83%. There was significant difference (p<0.05 at dose 160 mg/200 g BB to negative control. From this study can be concluded that essential oil kemangi leaves has anti-inflammatory activity.

  10. Anti-inflammatory activity of Ocimum americanum L. essential oil in experimental model of zymosan-induced arthritis.

    Science.gov (United States)

    Yamada, Alciléia Nunes; Grespan, Renata; Yamada, Áureo Tatsumi; Silva, Expedito Leite; Silva-Filho, Saulo Euclides; Damião, Marcio José; de Oliveira Dalalio, Márcia Machado; Bersani-Amado, Ciomar Aparecida; Cuman, Roberto Kenji Nakamura

    2013-01-01

    Essential oils are potential sources of novel components for medicinal use. The present study was performed to investigate the composition and anti-inflammatory activity of Ocimum americanum L. essential oil (OEO) and its components in an experimental model of zymosan-induced arthritis and paw edema. The essential oil was obtained by hydro-distillation and analyzed by gas chromatography-mass spectrometry. Twenty-six components, representing 98.9% of the total oil, were characterized, with linalool (19.63%) and 1,8-cineole (17.27%) as the main components. The OEO and its two constituents inhibited leukocyte influx into the synovial space and reduced paw edema induced by zymosan. The OEO also inhibited interferon-γ levels but did not reduce transforming growth factor-β levels. Additionally, the OEO protected against leukocyte influx into the synovial membrane and cartilage destruction in knee joints in arthritic mice. These findings indicate that the essential oil of Ocimum americanum L. exerted significant anti-inflammatory effects, likely related to its main compounds.

  11. Weed hosts of cotton mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae).

    Science.gov (United States)

    Vennila, S; Prasad, Y G; Prabhakar, M; Agarwal, Meenu; Sreedevi, G; Bambawale, O M

    2013-03-01

    The exotic cotton mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) invaded India during 2006, and caused widespread infestation across all nine cotton growing states. P. solenopsis also infested weeds that aided its faster spread and increased severity across cotton fields. Two year survey carried out to document host plants of P. solenopsis between 2008 and 2010 revealed 27, 83, 59 and 108 weeds belonging to 8, 18, 10 and 32 families serving as alternate hosts at North, Central, South and All India cotton growing zones, respectively. Plant species of four families viz., Asteraceae, Amaranthaceae, Malvaceae and Lamiaceae constituted almost 50% of the weed hosts. While 39 weed species supported P. solenopsis multiplication during the cotton season, 37 were hosts during off season. Higher number of weeds as off season hosts (17) outnumbering cotton season (13) at Central over other zones indicated the strong carryover of the pest aided by weeds between two cotton seasons. Six, two and seven weed hosts had the extreme severity of Grade 4 during cotton, off and cotton + off seasons, respectively. Higher number of weed hosts of P. solenopsis were located at roadside: South (12) > Central (8) > North (3) zones. Commonality of weed hosts was higher between C+S zones, while no weed host was common between N+S zones. Paper furnishes the wide range of weed hosts of P. solenopsis, discusses their significance, and formulated general and specific cultural management strategies for nationwide implementation to prevent its outbreaks.

  12. Effects of two commercial neem-based insecticides on lone star tick, Amblyomma americanum (L.) (Acari: Ixodidae): deterrence, mortality, and reproduction

    Science.gov (United States)

    The lone star tick, Amblyomma americanum (L.), is a widely distributed three-host obligate blood-feeding parasite in the United States and Mexico. It mostly attaches to white-tailed deer, Odocoilus virginianus (Zimmerman) and wild turkey, Meleagris gallopavo L., as well as a wide variety of other do...

  13. Weeds optimally grow in peat swamp after burning

    Directory of Open Access Journals (Sweden)

    P.D. Susanti

    2014-07-01

    Full Text Available After clearing land by burning the peat, then the weeds and undergrowth will flourish. Even sometimes, the weeds are eventually burned again. Weed is known as a destroyer plant that has to be controlled. Through proper treatment, the existing weeds in peatlands can be potentiallly exploited. The purpose of this study was to determine the calorific value of briquettes as one of peatland weeds utilization. The results showed that the calorific value ranged from 2,492 cal/g to 5,230 cal/g. The lowest calorific value was on ‘teki kecil’ grass (Scirpus grossus Lf, while the highest calorific value was observed for ‘bantalaki grass’ (Hymenachne amplexicaulis Nees. The high calorific value of the peat weeds are potential for biomass briquettes raw materials. The utilization and use of peat weed briquettes as a raw materials expected can reduce land degradation due to peat swamp burning

  14. WEEDS IDENTIFICATION USING EVOLUTIONARY ARTIFICIAL INTELLIGENCE ALGORITHM

    Directory of Open Access Journals (Sweden)

    Ahmed M. Tobal

    2014-01-01

    Full Text Available In a world reached a population of six billion humans increasingly demand it for food, feed with a water shortage and the decline of agricultural land and the deterioration of the climate needs 1.5 billion hectares of agricultural land and in case of failure to combat pests needs about 4 billion hectares. Weeds represent 34% of the whole pests while insects, diseases and the deterioration of agricultural land present the remaining percentage. Weeds Identification has been one of the most interesting classification problems for Artificial Intelligence (AI and image processing. The most common case is to identify weeds within the field as they reduce the productivity and harm the existing crops. Success in this area results in an increased productivity, profitability and at the same time decreases the cost of operation. On the other hand, when AI algorithms combined with appropriate imagery tools may present the right solution to the weed identification problem. In this study, we introduce an evolutionary artificial neural network to minimize the time of classification training and minimize the error through the optimization of the neuron parameters by means of a genetic algorithm. The genetic algorithm, with its global search capability, finds the optimum histogram vectors used for network training and target testing through a fitness measure that reflects the result accuracy and avoids the trial-and-error process of estimating the network inputs according to the histogram data.

  15. Alternathera philoxeroides (Martius) Grisebach - alligator weed

    Science.gov (United States)

    Biological control of Alternanthera philoxeroides, alligator weed, began when George Vogt, USDA, conducted several surveys by public transport in South America during the 1960s. Three agents were released in USA and two of them, the flea beetle Agasicles hygrophila and the moth Arcola malloi were re...

  16. Weed Control in Black Walnut Plantations

    Science.gov (United States)

    Calvin F. Bey; Robert D. Williams

    1976-01-01

    Weeds must be controlled for at least 3 years to successfully establish walnut plantations. Whether by cultivating or applying chemicals, a strip or spot 4 feet wide is sufficient the first 2 years, followed by a 6-foot spot or strip for the third and fourth years.

  17. Weed Control Trials in Cottonwood Plantations

    Science.gov (United States)

    R. M. Krinard

    1964-01-01

    Weed control in the first year is essential for establishing a cottonwood plantation, for the young trees can neither survive nor grow well if they must compete with other plants. Once the light and moisture conditions are established in its favor, cottonwood becomes the fastest growing tree in the South.

  18. Acetic acid and weed control in onions

    Science.gov (United States)

    Weed control is a major challenge in conventional and organic production systems, especially for organically produced sweet onion (Allium cepa L.). Although corn gluten meal shows great promise as an organic preemergent herbicide for onions, research has shown the need for supplemental, postemergen...

  19. Characterization of rhizobacteria associated with weed seedlings.

    Science.gov (United States)

    Kremer, R J; Begonia, M F; Stanley, L; Lanham, E T

    1990-06-01

    Rhizobacteria were isolated from seedlings of seven economically important weeds and characterized for potential phytopathogenicity, effects on seedling growth, and antibiosis to assess the possibility of developing deleterious rhizobacteria as biological control agents. The abundance and composition of rhizobacteria varied among the different weed species. For example, fluorescent pseudomonads represented from 11 to 42% of the total rhizobacterial populations from jimsonweed and lambsquarters, respectively. Other bacteria frequently isolated were nonfluorescent pseudomonads, Erwinia herbicola, Alcaligenes spp., and Flavobacterium spp. Only 18% of all isolates were potentially phytopathogenic, based on an Escherichia coli indicator bioassay. However, the proportion of isolates that inhibited growth in seedling assays ranged from 35 to 65% depending on the weed host. Antibiosis was most prevalent among isolates of fluorescent Pseudomonas spp., the activity of which was due to siderophore production in over 75% of these isolates. Overall, rhizobacterial isolates exhibited a complex array of properties that were inconsistent with accepted definitions for plant growth-promoting and deleterious rhizobacteria. It is suggested that for development of effective biological control agents for weed control, deleterious rhizobacteria must be screened directly on host seedlings and must possess several properties including high colonizing ability, specific phytotoxin production, and resistance or tolerance to antibiotics produced by other rhizosphere microorganisms, and they must either synthesize or utilize other bacterial siderophores.

  20. Weed Science and Technology. MP-17.

    Science.gov (United States)

    Alley, Harold P.; Lee, Gary A.

    This document is one in a series distributed by the Agricultural Extension Service of the University of Wyoming-Laramie. It presents the principles and methods of weed control especially as it relates to the use of herbicides. The factors influencing the effectiveness of both foliar-applied and soil-applied herbicides are discussed. A listing of…

  1. Weed Science and Technology. MP-17.

    Science.gov (United States)

    Alley, Harold P.; Lee, Gary A.

    This document is one in a series distributed by the Agricultural Extension Service of the University of Wyoming-Laramie. It presents the principles and methods of weed control especially as it relates to the use of herbicides. The factors influencing the effectiveness of both foliar-applied and soil-applied herbicides are discussed. A listing of…

  2. Bio-gas production from alligator weeds

    Science.gov (United States)

    Latif, A.

    1976-01-01

    Laboratory experiments were conducted to study the effect of temperature, sample preparation, reducing agents, light intensity and pH of the media, on bio-gas and methane production from the microbial anaerobic decomposition of alligator weeds (Alternanthera philoxeroides. Efforts were also made for the isolation and characterization of the methanogenic bacteria.

  3. Cutting weeds with a CO2 laser

    DEFF Research Database (Denmark)

    Heisel, T.; Schou, Jørgen; Christensen, S.

    2001-01-01

    treatment. The relationship between dry weight and laser energy was analysed using a non-linear dose-response regression model. The regression parameters differed significantly between the weed species. At all growth stages and heights S. arvensis was more difficult to cut with a CO2 laser than C. album...

  4. Central diabetes insipidus following digestion Solanum indicum L. concentrated solution.

    Science.gov (United States)

    Huang, Wen-Hung; Hsu, Ching-Wei; Fang, Ji-Tseng

    2008-04-01

    In Taiwan, Solanum indicum L. has been used in folk medicine for the treatment of inflammation, toothache, ascites, edema, and wound infection. The plant is rich in solanine, an alkaloidal glycoside. We report a 43-year-old man who developed polyuria and polydipsia after taking seven doses of concentrated solution of Solanum indicum L. over two weeks. A water deprivation test and a low serum antidiuretic hormone level helped to confirm a diagnosis of central diabetes insipidus. We suggest that excessive doses of Solanum indicum L. may cause central diabetes insipidus.

  5. RNAseq reveals weed-induced PIF3-like as a candidate target to manipulate weed stress response in soybean.

    Science.gov (United States)

    Horvath, David P; Hansen, Stephanie A; Moriles-Miller, Janet P; Pierik, Ronald; Yan, Changhui; Clay, David E; Scheffler, Brian; Clay, Sharon A

    2015-07-01

    Weeds reduce yield in soybeans (Glycine max) through incompletely defined mechanisms. The effects of weeds on the soybean transcriptome were evaluated in field conditions during four separate growing seasons. RNASeq data were collected from six biological samples of soybeans growing with or without weeds. Weed species and the methods to maintain weed-free controls varied between years to mitigate treatment effects, and to allow detection of general soybean weed responses. Soybean plants were not visibly nutrient- or water-stressed. We identified 55 consistently downregulated genes in weedy plots. Many of the downregulated genes were heat shock genes. Fourteen genes were consistently upregulated. Several transcription factors including a PHYTOCHROME INTERACTING FACTOR 3-like gene (PIF3) were included among the upregulated genes. Gene set enrichment analysis indicated roles for increased oxidative stress and jasmonic acid signaling responses during weed stress. The relationship of this weed-induced PIF3 gene to genes involved in shade avoidance responses in Arabidopsis provide evidence that this gene may be important in the response of soybean to weeds. These results suggest that the weed-induced PIF3 gene will be a target for manipulating weed tolerance in soybean.

  6. Changes in weed infestation of common bean (Phaseolus vulgaris L. under conditions of strip intercropping and different weed control methods

    Directory of Open Access Journals (Sweden)

    Aleksandra Głowacka

    2012-12-01

    Full Text Available The experiment was conducted in the years 2004-2006 in a private farm in the village of Frankamionka in Zamość district. There were two experimental factors: I. Cultivation methods - sole cropping and strip intercropping; and II. Tending methods - mechanical, mechanical-chemical, and chemical weed control. The subject of the study was weed infestation of the Mela variety of common bean. Beans were sown between 30 April and 5 May. Weed infestation was assessed in the last week before harvesting by determining its floristic composition and the frequency of occurrence of particular weed species, as well as the air-dry weight of weeds. The dominant weed species were Galinsoga parviflora, Echinochloa crus-galli, Chenopodium album, and Amaranthus retroflexus, which comprised 84.7% of the total number of weeds. Strip intercropping markedly reduced the number of weeds per unit area (by 50%, as well as the dry weight of their aerial parts. The most effective method of weed control was the mechanical-chemical method, which resulted in the lowest occurrence of weeds. It also significantly reduced the weight of weeds.

  7. Image analysis as a non-destructive method to assess regrowth of weeds after repeated flame weeding

    DEFF Research Database (Denmark)

    Rask, Anne Merete; Kristoffersen, Palle; Andreasen, Christian

    2013-01-01

    Efficient non-chemical weed control like flame weeding often requires repeated treatments. In weed control experiments the effect of each treatment may be estimated by removing and weighing the remaining weed biomass after the treatment, but the method influences the weed plants ability to regrow......, and therefore it may influence the long-term effect of repeated treatments. Visual assessment of weed cover or image analysis do not affect the remaining parts of the weed plants after treatment, but the methods may have other disadvantages. In order to evaluate and compare three methods we measured changes...... in vegetation cover of perennial ryegrass after flaming by (1) a simple image analysis programme counting green pixels, (2) visual assessment of images and (3) by taking biomass samples. Plants were flame treated with eight different dosages (0, 20, 30, 35, 45, 60, 90 and 180 kg propane ha-1) and with various...

  8. SolDB: A Database of Solanum lycopersicum and Solanum tuberosum Primers

    Directory of Open Access Journals (Sweden)

    Hassan Tariq

    2010-12-01

    Full Text Available SolDB is the Database of Solanaceae Family. It is an interactive, free online specialized database for Solanaceae family. Currently, it spans complete nucleotide sequences of expressed genes of Solanum lycopersicum and Solanum tuberosum along with their annotation. We have designed PCR oligonucleotide primer sequences for each gene, with their features and conditions given. This feature alone greatly facilitates researchers in PCR amplification of genes sequences, especially in cloning experiments. We also provided chloroplast genome section which gives access to fully sequenced plastid genomes and their annotations. Flexible database design, easy expandability, and easy retrieval of information are the main features of SolDB. The Database is publicly available at www.soldb.pakbiz.org.

  9. Chemical constituents of Solanum buddleifolium Sendtn; Constituintes quimicos de Solanum buddleifolium Sendtn

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Francisco das Chagas L.; Torres, Maria da conceicao M.; Silveira, Edilberto R.; Pessoa, Otilia Deusdenia L., E-mail: opessoa@ufc.br [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Centro de Ciencias. Dept. de Quimica Organica e Inorganica; Braz-Filho, Raimundo [Universidade Estadual do Norte Fluminense, Campos, RJ (Brazil). Dept. de Quimica; Guedes, Maria Lenise da Silva [Universidade Federal da Bahia (UFBA), Ondina, BA (Brazil). Inst. de Biologia. Dept. de Botanica

    2013-10-01

    The chemical investigation of the stem EtOH extract of S. buddleifolium resulted in the isolation of terpenoids, amides, lignans and a steroidal alkaloid. Based on HRMS, IR and {sup 1}H and {sup 13}C NMR data analysis, the structures of the isolated compounds were identified as: 13-hydroxysolavetivone, betulinic acid, N-trans-caffeoyltyramine, N-trans-feruloyldopamine, N-trans-p-cumaroyltyramine, N-trans-feruloyltyramine, N-trans-feruloyl- 3'-O-methoxydopamine, alangilignoside C, isolariciresinol, polistachiol, (+)-(8R,7'S,8'S)-3{alpha}-O-({beta}-D-glucopiranosyl)-lioniresinol, (-)-(8S,7'R,8'R)-3{alpha}-O-({beta}-D-glucopiranosyl)-lioniresinol and solamargine. The occurrence of terpenoids and amides is common in Solanum, unlike lignans which are rare. The isolated lignans described in this work are reported for the first time in the genus Solanum. (author)

  10. The benefits of using quantile regression for analysing the effect of weeds on organic winter wheat

    NARCIS (Netherlands)

    Casagrande, M.; Makowski, D.; Jeuffroy, M.H.; Valantin-Morison, M.; David, C.

    2010-01-01

    P>In organic farming, weeds are one of the threats that limit crop yield. An early prediction of weed effect on yield loss and the size of late weed populations could help farmers and advisors to improve weed management. Numerous studies predicting the effect of weeds on yield have already been

  11. High residue cultivation timing impact on organic no-till soybean weed management

    Science.gov (United States)

    A cereal rye cover crop mulch can suppress summer annual weeds early in the soybean growing season. However, a multi-tactic weed management approach is required when annual weed seedbanks are large or perennial weeds are present. In such situations, the weed suppression from a cereal rye mulch can b...

  12. The benefits of using quantile regression for analysing the effect of weeds on organic winter wheat

    NARCIS (Netherlands)

    Casagrande, M.; Makowski, D.; Jeuffroy, M.H.; Valantin-Morison, M.; David, C.

    2010-01-01

    P>In organic farming, weeds are one of the threats that limit crop yield. An early prediction of weed effect on yield loss and the size of late weed populations could help farmers and advisors to improve weed management. Numerous studies predicting the effect of weeds on yield have already been c

  13. Estrutura do capim-braquiária em relação à planta daninha = Structure of signalgrass in relation to weeds

    Directory of Open Access Journals (Sweden)

    Manoel Eduardo Rozalino Santos

    2011-07-01

    Full Text Available O objetivo foi avaliar as características estruturais da Brachiaria decumbens cv. Basilisk em relação à planta daninha Solanum sisymbrifolium no pasto. Os tratamentos foram dois locais no mesmo pasto, quais sejam, próximo e distante da planta daninha. O delineamento foi em blocos ao acaso com três repetições. O pasto foi manejado sob lotação contínua, com bovinos e com altura média de aproximadamente 25 cm. Foram quantificadas as densidades populacionais das categorias de tamanho dos perfilhos, a altura, a interceptação de luz, as massas e as densidades volumétricas dos componentes morfológicos do pasto. No local distante da planta daninha houve maior ocorrência de perfilhos com tamanho inferior a 20 cm. Já no local próximo da planta daninha, predominaram perfilhos com tamanho superior a 40 cm. A presença da planta daninha ocasionou aumento na altura do pasto e incremento na interceptação de luz pelo dossel. As massas e as densidades volumétricas de lâmina foliar viva, colmo vivo e material morto foram inferiores no local próximo da planta daninha em relação ao local distante. A ocorrência da planta S. sisymbrifolium provoca variabilidade espacial da vegetação no pasto de B. decumbens manejado sob lotação contínua com bovinos.The objective of this study was to evaluate the structural characteristics of Brachiaria decumbens cv. Basilisk in relation toSolanum sisymbrifolium in pasture. The treatments were two sites in the same pasture, near and far from the weeds. A randomized block design with three replications was used. The pasture was managed under continuous stocking and grass height was kept at about 25cm.Densities were quantified for categories tiller size, height, light interception, masses and volumetric densities of morphological components of the pasture. In the site far from the weeds there is a higher occurrence of tillers with size smaller than 20 cm. In site near the weeds, tillers larger than 40 cm

  14. Overview of tomato (Solanum lycopersicum) candidate pathogen recognition genes reveals important Solanum R locus dynamics.

    Science.gov (United States)

    Andolfo, G; Sanseverino, W; Rombauts, S; Van de Peer, Y; Bradeen, J M; Carputo, D; Frusciante, L; Ercolano, M R

    2013-01-01

    To investigate the genome-wide spatial arrangement of R loci, a complete catalogue of tomato (Solanum lycopersicum) and potato (Solanum tuberosum) nucleotide-binding site (NBS) NBS, receptor-like protein (RLP) and receptor-like kinase (RLK) gene repertories was generated. Candidate pathogen recognition genes were characterized with respect to structural diversity, phylogenetic relationships and chromosomal distribution. NBS genes frequently occur in clusters of related gene copies that also include RLP or RLK genes. This scenario is compatible with the existence of selective pressures optimizing coordinated transcription. A number of duplication events associated with lineage-specific evolution were discovered. These findings suggest that different evolutionary mechanisms shaped pathogen recognition gene cluster architecture to expand and to modulate the defence repertoire. Analysis of pathogen recognition gene clusters associated with documented resistance function allowed the identification of adaptive divergence events and the reconstruction of the evolution history of these loci. Differences in candidate pathogen recognition gene number and organization were found between tomato and potato. Most candidate pathogen recognition gene orthologues were distributed at less than perfectly matching positions, suggesting an ongoing lineage-specific rearrangement. Indeed, a local expansion of Toll/Interleukin-1 receptor (TIR)-NBS-leucine-rich repeat (LRR) (TNL) genes in the potato genome was evident. Taken together, these findings have implications for improved understanding of the mechanisms of molecular adaptive selection at Solanum R loci. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  15. The genomes of four novel begomoviruses and a new Sida micrantha mosaic virus strain from Bolivian weeds.

    Science.gov (United States)

    Wyant, Patrícia Soares; Gotthardt, Diether; Schäfer, Benjamin; Krenz, Björn; Jeske, Holger

    2011-02-01

    Begomovirus is the largest genus within the family Geminiviridae and includes economically important plant DNA viruses infecting a broad range of plant species and causing devastating crop diseases, mainly in subtropical and tropical countries. Besides cultivated plants, many weeds act as virus reservoirs. Eight begomovirus isolates from Bolivian weeds were examined using rolling-circle amplification (RCA) and restriction fragment length polymorphism (RFLP). An efficient, novel cloning strategy using limited Sau3A digestion to obtain tandem-repeat inserts allowed the sequencing of the complete genomes. The viruses were classified by phylogenetic analysis as typical bipartite New World begomoviruses. Four of them represented distinct new virus species, for which the names Solanum mosaic Bolivia virus, Sida mosaic Bolivia virus 1, Sida mosaic Bolivia virus 2, and Abutilon mosaic Bolivia virus are proposed. Three were variants of a new strain of Sida micrantha mosaic virus (SimMV), SimMV-rho[BoVi07], SimMV-rho[Bo:CF1:07] and SimMV-rho[Bo:CF2:07], and one was a new variant of a previously described SimMV, SimMV-MGS2:07-Bo.

  16. A non-chemical system for online weed control.

    Science.gov (United States)

    Rueda-Ayala, Victor; Peteinatos, Gerassimos; Gerhards, Roland; Andújar, Dionisio

    2015-03-30

    Non-chemical weed control methods need to be directed towards a site-specific weeding approach, in order to be able to compete the conventional herbicide equivalents. A system for online weed control was developed. It automatically adjusts the tine angle of a harrow and creates different levels of intensity: from gentle to aggressive. Two experimental plots in a maize field were harrowed with two consecutive passes. The plots presented from low to high weed infestation levels. Discriminant capabilities of an ultrasonic sensor were used to determine the crop and weed variability of the field. A controlling unit used ultrasonic readings to adjust the tine angle, producing an appropriate harrowing intensity. Thus, areas with high crop and weed densities were more aggressively harrowed, while areas with lower densities were cultivated with a gentler treatment; areas with very low densities or without weeds were not treated. Although the weed development was relatively advanced and the soil surface was hard, the weed control achieved by the system reached an average of 51% (20%-91%), without causing significant crop damage as a result of harrowing. This system is proposed as a relatively low cost, online, and real-time automatic harrow that improves the weed control efficacy, reduces energy consumption, and avoids the usage of herbicide.

  17. Weed infestation of onion in soil reduced cultivation system

    Directory of Open Access Journals (Sweden)

    Marzena Błażej-Woźniak

    2013-12-01

    Full Text Available Field experiment was conducted in the years 1998-2000 in GD Felin. The influence of no-tillage cultivation and conventional tillage with spring ploughing on weed infestation of onion was compared. In experiment four cover crop mulches (Sinapis alba L., Vicia sativa L., Phacelia tanacetifolia B., Avena sativa L. were applied. From annual weeds in weed infestation of onion in great number Matricaria chamomilla L., and Senecio vulgaris L. stepped out. and from perennial - Agropyron repens (L.P.B. Reduced soil cultivation system (no-tillage caused the significant growth of primary weed infestation of onion in comparison with conventional tillage. In all years of investigations the executed pre-sowing ploughing limited significantly the annual weeds' number in primary weed infestation. The applied mulches from cover plants limited in considerable degree the number of primary weed infestation. In all years of investigations the most weeds stepped out on control object. Among investigated cover crop mulches Vicia sativa L. and Avena sativa L. had a profitable effect on decrease of onion`s primary weed infestation. Soil cultivation system and cover crop mulches had no signi ficant residual influence on the secondary weed infestation of onion.

  18. Effect of foliar fertilisation on growth of solanum trilobatum L.

    Science.gov (United States)

    Balu, S; Madhavan, S; Babu, T

    1996-01-01

    The effects of the fertilizers, CYTOZYME, MIRACLE, PLANOFIX and VIPUL on Solanum trilobatum were studied CYTOZYME showed improved morphometric performance and the highest yield. VIPUL contributed greater drought resistance to the medicinal plant.

  19. STEROIDAL GLYCOSIDES FROM THE ROOTS OF SOLANUM MELONGENA L.

    Directory of Open Access Journals (Sweden)

    Stepan Shvets

    2009-12-01

    Full Text Available One new cholestane glycoside, six steroidal glycosides of spirostane series and one pregnane glycoside have been isolated from the roots of Solanum melongena L. for the first time. Their structures were determined by physico-chemical methods.

  20. Weed Biomass and Weed Species Diversity of Juvenile Citrus Trees Intercrop with some Arable Crops

    Directory of Open Access Journals (Sweden)

    Patience Mojibade OLORUNMAIYE

    2012-02-01

    Full Text Available A preliminary study was carried out to evaluate the performances of eight crops in the intercrop of citrus with arable crops at the National Horticultural Research Institute (NIHORT Ibadan, Nigeria. Eight arable crops: maize, cucumber, sweet potato, Corchorus olitorius, large green, grain amaranth, Mucuna pruriens var. utilis, and groundnut were intercropped with young citrus trees in the early planting season of 2010 with sole citrus as control. The experiment was laid out in a completely randomized block design with three replicates. Data were collected on weed flora, weed density and weed dry weight. Results showed that the relative frequencies of weeds in all the plots were less than 4% at both 6 and 9WAP. Gomphrena celosoides, Oldenlandia corymbosa and Tridax procumbens were most preponderant in appearing in all the plots. Tridax procumbens had a consistent relative frequency (2.34% in all the plots except in citrus/maize plot (0.78% at 9 WAP. Significantly lower broadleaf weed densities were obtained in citrus/sweet potato, citrus/large green, control plot and citrus/cucumber (28.67, 45.00, 50.00 and 76.33 m-2 respectively than in citrus/groundnut plot (143.00 m-2. Similarly, significantly lower grass weed densities were produced in citrus/Mucuna and citrus/sweet potato (0.33 m-2 each plots than the control plot (11.33 m-2. Whereas citrus/corchorus plot produced significantly lower broadleaf weed dry weight (37.59 g m-2 than citrus/Mucuna plot (126.47 g m-2 at 3WAP, citrus/large green plot (16.15 g m-2 and citrus/groundnut plot (123.25 g m-2 followed the same trend at 6 WAP. Sedges dry weights were less than 7 g m-2 in all the plots compared with control plot.

  1. Weed Biomass and Weed Species Diversity of Juvenile Citrus Trees Intercrop with some Arable Crops

    Directory of Open Access Journals (Sweden)

    Patience Mojibade OLORUNMAIYE

    2012-02-01

    Full Text Available A preliminary study was carried out to evaluate the performances of eight crops in the intercrop of citrus with arable crops at the National Horticultural Research Institute (NIHORT Ibadan, Nigeria. Eight arable crops: maize, cucumber, sweet potato, Corchorus olitorius, large green, grain amaranth, Mucuna pruriens var. utilis, and groundnut were intercropped with young citrus trees in the early planting season of 2010 with sole citrus as control. The experiment was laid out in a completely randomized block design with three replicates. Data were collected on weed flora, weed density and weed dry weight. Results showed that the relative frequencies of weeds in all the plots were less than 4% at both 6 and 9WAP. Gomphrena celosoides, Oldenlandia corymbosa and Tridax procumbens were most preponderant in appearing in all the plots. Tridax procumbens had a consistent relative frequency (2.34% in all the plots except in citrus/maize plot (0.78% at 9 WAP. Significantly lower broadleaf weed densities were obtained in citrus/sweet potato, citrus/large green, control plot and citrus/cucumber (28.67, 45.00, 50.00 and 76.33 m-2 respectively than in citrus/groundnut plot (143.00 m-2. Similarly, significantly lower grass weed densities were produced in citrus/Mucuna and citrus/sweet potato (0.33 m-2 each plots than the control plot (11.33 m-2. Whereas citrus/corchorus plot produced significantly lower broadleaf weed dry weight (37.59 g m-2 than citrus/Mucuna plot (126.47 g m-2 at 3WAP, citrus/large green plot (16.15 g m-2 and citrus/groundnut plot (123.25 g m-2 followed the same trend at 6 WAP. Sedges dry weights were less than 7 g m-2 in all the plots compared with control plot.

  2. Resolution by recombination: breaking up Solanum pennellii introgressions.

    Science.gov (United States)

    Alseekh, Saleh; Ofner, Itai; Pleban, Tzili; Tripodi, Pasquale; Di Dato, Francesco; Cammareri, Maria; Mohammad, Ayed; Grandillo, Silvana; Fernie, Alisdair R; Zamir, Dani

    2013-10-01

    Quantitative trait locus (QTL) genetics retains an important role in the study of biological and agronomic processes; however, its genetic resolution is often comparatively low. Community-based strategies are thus required to address this issue. Here we detail such a strategy wherein the widely used Solanum pennellii introgression lines (ILs) in the genetic background of the cultivated tomato (Solanum lycopersicum) are broken up into molecular marker-defined sublines as a community resource for map-based cloning.

  3. Plastid transformation in potato: Solanum tuberosum.

    Science.gov (United States)

    Valkov, Vladimir T; Gargano, Daniela; Scotti, Nunzia; Cardi, Teodoro

    2014-01-01

    Although plastid transformation has attractive advantages and potential applications in plant biotechnology, for long time it has been highly efficient only in tobacco. The lack of efficient selection and regeneration protocols and, for some species, the inefficient recombination using heterologous flanking regions in transformation vectors prevented the extension of the technology to major crops. However, the availability of this technology for species other than tobacco could offer new possibilities in plant breeding, such as resistance management or improvement of nutritional value, with no or limited environmental concerns. Herein we describe an efficient plastid transformation protocol for potato (Solanum tuberosum subsp. tuberosum). By optimizing the tissue culture system and using transformation vectors carrying homologous potato flanking sequences, we obtained up to one transplastomic shoot per bombardment. Such efficiency is comparable to that usually achieved in tobacco. The method described in this chapter can be used to regenerate potato transplastomic plants expressing recombinant proteins in chloroplasts as well as in amyloplasts.

  4. Acidulocompost, a food waste compost with thermophilic lactic acid fermentation: its effects on potato production and weed growth

    Directory of Open Access Journals (Sweden)

    Naomi Asagi

    2016-01-01

    Full Text Available Acidulocomposting recycles food wastes by means of thermophilic lactic acid fermentation. This process can decrease ammonia volatilization and odor emission during processing and produce compost with high nitrogen (N content. To compare the yield of potatoes (Solanum tuberosum L. ‘Dansyakuimo’ and the suppression of weeds with acidulocompost (AC and those with conventional composts and inorganic fertilizer (IF, we conducted field experiments in Miyagi Prefecture, northeastern Japan. Potatoes were cultivated in 2008 and 2009 in an Andosol field treated with AC, conventional food waste compost (FWC, poultry manure compost (PMC, cattle manure compost (CMC, IF, or no fertilizer (NF. AC, but not the other treatments, delayed the emergence of potatoes, and suppressed the emergence of weeds, but it did not inhibit potato growth during the late growth stage or yield. Potato N uptake and tuber yield with AC were significantly higher than those with NF and similar to those with FWC, PMC, and IF. The N uptake efficiencies (ratio of difference between N uptake in the treatment and the control to added N for AC (10.4–12.7% in 2008 and 2009 were similar to those for FWC and PMC (10.2–13.1%, higher than those for CMC (–1.3 to 6.3%, but significantly lower than those for IF (30.2–42.3%. Our findings indicate that AC has an N supply capacity similar to those of FWC and PMC and additionally suppresses the emergence and growth of weeds.

  5. Determination of Allelopathic Effect of Some Invasive Weed Species on Germination and Initial Development of Grain Legume Crops

    Directory of Open Access Journals (Sweden)

    Plamen Marinov-Serafimov

    2010-01-01

    Full Text Available During the 2006-2007 period, the allelopathic effect of cold water extracts from Amaranthus retroflexus L., Chenopodium album L., Erigeron canadensis L. and Solanum nigrum L. on seed germinationand initial development of Glycine max L., Pisum sativum L. and Vicia sativa L. was studied under laboratory conditions in the Institute of Forage Crops, Pleven. It was found that: waterextracts from fresh and dry biomass of A. retroflexus, Ch. album, E. canadensis and S. nigrum had an inhibitory effect on seed ermination of G. max, P. sativum and V. sativa, the inhibition rate for the extracts from fresh biomass varying from 28.8 to 81.5% and for the extracts from dry weed biomass it was from 26.8 tо 89.2%; The values of LC50 varied from 13.5 tо 72.2 g l-1 for the extracts from fresh biomass and from 7.0 tо 84.1 g l-1 for the extracts from dry weed biomass and they could be conditionally grouped in the following ascending order: A. retroflexus < S. nigrum < E.canadensis weed biomass - LC50 varied from 13.5 tо 21.6 g l-1, followed by V. sativa - LC50 from 26.0 tо 11.7 g l-1 and G. max had relatively the lowest sensitivity - LC50 was from 46.6 tо 56.7 g l-1.

  6. Caracterização morfológica das unidades de dispersão e das plantulas de cinco espécies invasoras da família Malvaceae Morphological characterization of the dispersal units and of the seedlings of five weed species of the Malvaceae family

    Directory of Open Access Journals (Sweden)

    D. Groth

    1984-01-01

    Full Text Available O objetivo deste trabalho foi ilustrar e caracterizar morfológica mente as unidades de dispersão (carpídios das espécies Malva parviflora L., Malvastrum americanum Torr., Malvastrum coromandelianum (L. Garcke, Sida glaziovii K. Schum., Sida linifolia Cav., permitindo uma clara diferenciação taxonômica entre elas, bem como descrever suas plântulas. São apresentadas duas chaves dicotômicas para auxiliar na identificação das unidades de dispersão e das plântulas, bem como descrições morfológicas da família Malvaceae e uma descrição detalhada dos carpídios e das plântulas e cada espécie estudada.The objective of this work was to characterize morphologically the dispersal units (mericarp of the weed species of Malva parviflora L. Malvastrum americanum Torr., Malvastrum coromandelianum (L. Garcke, Sida glaziovii K. Schum., Sida linif olia Cav., in order to allow a clear taxonomical diffe rentiation among them, as well as to make a description of thei r seedlings. Two taxonomical keys are presented in order to help the identification of the dispersal units and the seedlings, as well as morphological descriptions of the Malvaceae family and a more detailed description of the meric arps and the seedl ings of each studied species.

  7. Water management as a key component of integrated weed management

    Directory of Open Access Journals (Sweden)

    Giuseppe Zanin

    2011-02-01

    Full Text Available Water management within the cropping system is a key factor for an integrated weed management. Soil moisture affects seed persistence and seed dormancy, thus influencing their germination, the establishment of seedlings as well as the competition at adult stage and the number, vitality and dormancy of the new seeds produced by the weeds. The interactions among water availability and competition are very complex and still not fully understood. A research effort in this sector should the be very relevant for the development of new approaches of weed management, such as “Ecological weed management”, aiming to reduce weed density and competitiveness and, in the medium term, to prevent undesired modifications of the weed flora.

  8. A New Hoe Blade for Inter-Row Weeding

    DEFF Research Database (Denmark)

    Green, O.; Znova, L.; Melander, Bo

    2016-01-01

    , for example uncontrollable sideward soil movement causing injurious coverage of crop plants. Based on feedbacks from researchers and practioners, a new device has been designed to overcome most of the problems associated with ‘Ducksfoot’ blades. The device consists of a stiff shank mounted on a curved VCO......New camera-based systems for automatic steering of inter-row cultivators have made it possible to conduct inter-row weeding in small inter-row spaces at reasonable work rates. This has motivated organic growers to shift from full-width weed harrowing of small grain cereals to inter-row hoeing....... The aim is mainly to improve weeding effectiveness against tall-growing and tap-rooted weed species. The ‘Ducksfoot’ hoe blade is commonly used for traditional inter-row weeding in row crops such as sugar beets and maize. This blade usually provides satisfactory weed control, if soils are not too wet...

  9. SPECIES COMPOSITION OF WEED VEGETATION IN DIFFERENT APPLE GROWING TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    Venera TASSEVA

    2005-08-01

    Full Text Available The investigation was carried out in the period 2001-2003 in an orchard of the Institute of Agriculture, Kyustendil, Bulgaria, created in the spring of 1996 on leached cinnamonic forest soil. The weed populations under four different farming technologies of growing of apple cultivar Florina were investigated. It was established, that the apple growing technologies influence the weed association composition. The highest weed diversity was found in the organic technology - 16 weed species were found. In the application of resource economical and integrated technologies, the development of 13-14 weed species was established. The smallest weed diversity was observed in the conventional technology - eight species, which was due to the twofold herbicide application.

  10. Lead residues in eastern tent caterpillars (Malacosoma americanum) and their host plant (Prunus serotina) close to a major highway

    Science.gov (United States)

    Beyer, W.N.; Moore, J.

    1980-01-01

    Eastern tent caterpillars, Malacosoma americanum (F.) (Lepidoptera: Lasiocampidae and leaves of their host plant, black cherry, Prunus serotina Ehrh., were collected in May, 1978, at various distances from the Baltimore-Washington Parkway, Prince George's Co., MD, and were analyzed for lead by atomic absorption spectrophotometry. Caterpillars collected within 10 m of the parkway contained 7.1-7.4 ppm lead (dry weight). Caterpillars collected at greater distances from the parkway and from a control area had lead concentrations ca. half as high (2.6-5.3 ppm). Lead concentrations in caterpillars averaged 76% as high as those in leaves and were much lower than concentrations that have been reported in some roadside soil and litter invertebrates

  11. Lead residues in eastern tent caterpillars (Malacosoma americanum) and their host plant (Prunus serotina) close to a major highway

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, W.N.; Moore, J.

    1980-02-01

    Eastern tent caterpillars, Malacosoma americanum (F.) (Lepidoptera: Lasiocampidae), and leaves of their host plant, black cherry, Prunus serotina Ehrh., were collected in May, 1978, at various distances from the Baltimore-Washington Parkway, Prince George's Co., MD, and were analyzed for lead by atomic absorption spectrophotometry. Caterpillars collected within 10 m of the parkway contained 7.1 to 7.4 ppM lead (dry weight). Caterpillars collected at greater distances from the parkway and from a control area had lead concentrations ca. half as high (2.6 to 5.3 ppM). Lead concentrations in caterpillars averaged 76% as high as those in leaves and were much lower than concentrations that have been reported in some roadside soil and litter invertebrates.

  12. Weeding the Astrophysical Garden: Ethyl Cyanide

    Science.gov (United States)

    De Lucia, F. C.; Fortman, S. M.; Medvedev, I. R.; Neese, C. F.

    2009-12-01

    It is well known that many, if not most, of the unidentified features in astrophysical spectra arise from relatively low lying excited vibrational and torsional states of a relatively small number of molecular species— the astrophysical weeds. It is also well known that the traditional quantum mechanical assignment and fitting of these excited state spectra is a formidable task, one that is made harder by the expected perturbations and interactions among these states. We have previously proposed an alternative fitting and analysis approach based on experimental, intensity calibrated spectra taken at many temperatures. In this paper we discuss the implementation of this approach and provide details in the context of one of these weeds, ethyl cyanide.

  13. Effect of tillage on the efficacy of CGA362622 on weed control in maize

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-03

    Dec 3, 2008 ... help in managing herbicide resistance weeds and may also increase weed density as well as reduce crop yield. (Anderson, 2004). Higher dose of .... This change in weed compo- sition agrees with Richley et al. (1977) ...

  14. Evaluation of Growth and Species Composition of Weeds in Maize-Cowpea Intercropping based on Additive Series under Organic Farming Condition

    Directory of Open Access Journals (Sweden)

    Hamdollah Eskandari

    2016-11-01

    relative yield total (RYT index. Weed smothering efficiency (WSE was used to evaluate the effect of intercropping on reducing weeds the dry weight. Results and discussion Results indicated that soil moisture content, PAR interception and soil temperature were affected by cropping patterns. The lowest and highest values of soil temperatures were observed in intercropping and sole crop systems, respectively. Intercropping systems exploited soil water more than sole crops. PAR interception was higher in intercropping compared to sole cropping. However, sole cowpea showed lower PAR interception compared to maize sole crop. Relative yield total (RYT index was more than unity in all intercropping systems. Weed smothering efficiency (WSE showed that dry weight of weeds was reduced by 21-26 and 28-42 percentages in intercropping systems compared to sole maize and sole cowpea cropping systems, respectively. The growth of weeds (in terms of total dry weight in intercropping systems were reduced in which from five recorded weed species, the dry weight of them, including amaranth (Amaranthus retondus L., pigweed (Echinocloa cruss-gali L., purslane (Portulaca oleraceae L. and Halikakabon (Solanum nigrum L. decreased in intercropping compared to sole cropping systems. Intercropping components showed a complementary relation in consuming environmental resources including soil moisture and PAR. Since the soil temperature was lower in intercropping compared to sole cropping, lower soil moisture in intercropping cannot be resulted from higher evaporation in intercropping, but also the widespread root system in intercropping resulted in higher efficiency in soil moisture consuming. Relative yield total more than unity, showing the advantages of intercropping in environmental resources consumption. Soil covering and higher biodiversity are two main factors reducing weeds growth in intercropping because the two recent factors lower PAR availability for weeds which can reduce weed. The current

  15. ThermaCELL and OFF! Clip-On Devices Tested for Repellency and Mortality Against Amblyomma americanum (Acari: Ixodida: Amblyommidae).

    Science.gov (United States)

    Bibbs, Christopher S; Xue, Rui-De

    2016-07-01

    The ThermaCELL with allethrin and OFF! Clip-on with metofluthrin were tested in a 939 m(2) vented enclosure against nymphal lone star ticks, Amblyomma americanum (L.). Repellency assays were conducted at varying distances relative to product specifications for repellency range. Nymphal ticks acclimated for 24 h in chambers attached to 10 repellency tracks per repetition. Devices were turned on, and the tick travel distance and delay until beginning to travel were recorded. Mortality of ticks was recorded after 24 h. Mortality assays were also conducted at the same distances with five ticks per cage, and 12 cages per distance radially distributed around a device. Cages were removed after 5 min, 15 min, 30 min, and 60 min of exposure and checked after 24 h for mortality. Significant travel distance was found when exposed to the ThermaCELL and OFF! Clip-on at their shortest test distances. Significant mortality also resulted at the same distances. Ticks exposed to active devices for longer than 15 min had significant mortality at the shortest distance for OFF! Clip-on and multiple distances for the ThermaCELL. Overall, the spatial repellent devices ThermaCELL with allethrin and OFF! Clip-on with metofluthrin both demonstrated desirable effects when tested against A. americanum nymphs. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. The genome sequence of Lone Star virus, a highly divergent bunyavirus found in the Amblyomma americanum tick.

    Directory of Open Access Journals (Sweden)

    Andrea Swei

    Full Text Available Viruses in the family Bunyaviridae infect a wide range of plant, insect, and animal hosts. Tick-borne bunyaviruses in the Phlebovirus genus, including Severe Fever with Thrombocytopenia Syndrome virus (SFTSV in China, Heartland virus (HRTV in the United States, and Bhanja virus in Eurasia and Africa have been associated with acute febrile illness in humans. Here we sought to characterize the growth characteristics and genome of Lone Star virus (LSV, an unclassified bunyavirus originally isolated from the lone star tick Amblyomma americanum. LSV was able to infect both human (HeLa and monkey (Vero cells. Cytopathic effects were seen within 72 h in both cell lines; vacuolization was observed in infected Vero, but not HeLa, cells. Viral culture supernatants were examined by unbiased deep sequencing and analysis using an in-house developed rapid computational pipeline for viral discovery, which definitively identified LSV as a phlebovirus. De novo assembly of the full genome revealed that LSV is highly divergent, sharing <61% overall amino acid identity with any other bunyavirus. Despite this sequence diversity, LSV was found by phylogenetic analysis to be part of a well-supported clade that includes members of the Bhanja group viruses, which are most closely related to SFSTV/HRTV. The genome sequencing of LSV is a critical first step in developing diagnostic tools to determine the risk of arbovirus transmission by A. americanum, a tick of growing importance given its expanding geographic range and competence as a disease vector. This study also underscores the power of deep sequencing analysis in rapidly identifying and sequencing the genomes of viruses of potential clinical and public health significance.

  17. Occurrence of novel verrucomicrobial species, endosymbiotic and associated with parthenogenesis in Xiphinema americanum-group species (Nematoda, Longidoridae).

    Science.gov (United States)

    Vandekerckhove, T T; Willems, A; Gillis, M; Coomans, A

    2000-11-01

    Numerous micro-organisms have been described as cytoplasmic symbionts of eukaryotes. Many so-called obligate endosymbionts rely exclusively on maternal (vertical or transovarial) transmission to maintain themselves, rendering them dependent on the host sex ratio, which they would tend to manipulate to their own advantage. The latter phenomenon is often associated with the presence of Wolbachia pipientis (alpha-Proteobacteria) in arthropods and nematodes. A potentially similar situation was discovered involving members of a new clade of Verrucomicrobia, another main line of descent in the Bacteria. Nematode species of the Xiphinema americanum group (Nematoda, Longidoridae), viz. Xiphinema americanum, Xiphinema rivesi and Xiphinema brevicollum, each harbour their own specific verrucomicrobial endosymbionts. They are exclusively maternally inherited and their hosts reproduce by thelytokous (mother-to-daughter) parthenogenesis, males being extremely rare. A new genus, 'Candidatus Xiphinematobacter' gen. nov., along with three new candidate verrucomicrobial species, 'Candidatus Xiphinematobacter americani' sp. nov., 'Candidatus Xiphinematobacter rivesi' sp. nov. and 'Candidatus Xiphinematobacter brevicolli' sp. nov., are described on the basis of transmission electron microscopy, scanning electron microscopy, DAPI (4',6-diamidino-2-phenylindole) epifluorescence microscopy and 16S rDNA sequence analysis. These are the first endosymbiotic species described among the Verrucomicrobia. They share a mean 16S rDNA similarity of about 93%, whereas similarity to their closest relative, clone WCHD3-88, is less than 87%. Thus, the endosymbionts form a homogeneous clade for which the new candidate genus 'Candidatus Xiphinematobacter' gen. nov. is proposed. The type species is 'Candidatus Xiphinematobacter brevicolli' sp. nov.

  18. Controlling weeds with fungi, bacteria and viruses: a review

    OpenAIRE

    Harding, Dylan P.; Raizada, Manish N

    2015-01-01

    Weeds are a nuisance in a variety of land uses. The increasing prevalence of both herbicide resistant weeds and bans on cosmetic pesticide use has created a strong impetus to develop novel strategies for controlling weeds. The application of bacteria, fungi and viruses to achieving this goal has received increasingly great attention over the last three decades. Proposed benefits to this strategy include reduced environmental impact, increased target specificity, reduced development costs comp...

  19. Determination of the critical period of weed control in corn using a thermal basis.

    OpenAIRE

    BEDMAR,FRANCISCO; Manetti,Pablo; MONTERUBBIANESI,GLORIA

    1999-01-01

    Field studies were conducted over 3 years in southeast Buenos Aires, Argentina, to determine the critical period of weed control in maize (Zea mays L.). The treatments consisted of two different periods of weed interference, a critical weed-free period, and a critical time of weed removal. The Gompertz and logistic equations were fitted to relative yields representing the critical weed-free and the critical time of weed removal, respectively. Accumulated thermal units were used to describe ea...

  20. Critical period of weed control in aerobic rice.

    Science.gov (United States)

    Anwar, M P; Juraimi, A S; Samedani, B; Puteh, A; Man, A

    2012-01-01

    Critical period of weed control is the foundation of integrated weed management and, hence, can be considered the first step to design weed control strategy. To determine critical period of weed control of aerobic rice, field trials were conducted during 2010/2011 at Universiti Putra Malaysia. A quantitative series of treatments comprising two components, (a) increasing duration of weed interference and (b) increasing length of weed-free period, were imposed. Critical period was determined through Logistic and Gompertz equations. Critical period varied between seasons; in main season, it started earlier and lasted longer, as compared to off-season. The onset of the critical period was found relatively stable between seasons, while the end was more variable. Critical period was determined as 7-49 days after seeding in off-season and 7-53 days in main season to achieve 95% of weed-free yield, and 23-40 days in off-season and 21-43 days in main season to achieve 90% of weed-free yield. Since 5% yield loss level is not practical from economic view point, a 10% yield loss may be considered excellent from economic view point. Therefore, aerobic rice should be kept weed-free during 21-43 days for better yield and higher economic return.

  1. Team-up Crop Diversification and Weed Management: PRODIVA

    DEFF Research Database (Denmark)

    Gerowitt, B.; Melander, B.; Krawczyk, R.

    2015-01-01

    The research-network PRODIVA focuses on a better utilization of crop diversification for weed management in North European arable cropping systems. The goal is to maintain diverse arable weed vegetation that is manageable in the long-term and could fulfil other necessary systemfunctions including...... the results. Neither are crop diversification methods restricted to Organic Farming, nor can IWM (Integrated Weed Management) be successfully implemented without respecting the role of weeds in agro-ecosystems. The project “PRODIVA - Crop diversification and weeds“ is supported within the ERA-net CORE Organic...

  2. Herbicide-resistant weed management: focus on glyphosate.

    Science.gov (United States)

    Beckie, Hugh J

    2011-09-01

    This review focuses on proactive and reactive management of glyphosate-resistant (GR) weeds. Glyphosate resistance in weeds has evolved under recurrent glyphosate usage, with little or no diversity in weed management practices. The main herbicide strategy for proactively or reactively managing GR weeds is to supplement glyphosate with herbicides of alternative modes of action and with soil-residual activity. These herbicides can be applied in sequences or mixtures. Proactive or reactive GR weed management can be aided by crop cultivars with alternative single or stacked herbicide-resistance traits, which will become increasingly available to growers in the future. Many growers with GR weeds continue to use glyphosate because of its economical broad-spectrum weed control. Government farm policies, pesticide regulatory policies and industry actions should encourage growers to adopt a more proactive approach to GR weed management by providing the best information and training on management practices, information on the benefits of proactive management and voluntary incentives, as appropriate. Results from recent surveys in the United States indicate that such a change in grower attitudes may be occurring because of enhanced awareness of the benefits of proactive management and the relative cost of the reactive management of GR weeds.

  3. Floristic composition and weed biomass in organic alfalfa crop

    Directory of Open Access Journals (Sweden)

    Ilić Olivera M.

    2016-01-01

    Full Text Available The paper presents the results of floristic composition and weed biomass in organic alfalfa crop in different years of alfalfa growing. The experiment was conducted in experimental plots in Futog, during the vegetation period of 2015. The presence of 60 weed species was noted, 49 of all weeds were noticed in the third, 48 in the fourth and 34 in the fifth year of organic alfalfa growing. Quantitative and qualitative structure of weed community depended on the age of alfalfa crop. By the analysis of cover values and the degree of the presence of weed species, it can be seen that species: Rumex obtusifolius L., Taraxacum officinale Web., Cynodon dactylon Pers. and Artemisia vulgaris L. had the greatest significance on weed infestation of alfalfa. The largest number of weed species belonged to the families Poaceae and Asteraceae. The biological spectrum of weeds species was defined by the terophyta dominance, whose number was reduced due to the age of the crop, while the share of hemicryptophytes and geophytes was more or less constant. Although we found a considerable level of infestation of alfalfa, alfalfa biomass reached acceptable values that were significantly higher than the weed biomass, which was statistically highly significant.

  4. Exploring the effects of glyphosate products on weed composition

    Directory of Open Access Journals (Sweden)

    Koning, Laurie Anne

    2016-02-01

    Full Text Available Glyphosate is a non-selective, broad-spectrum, systematic herbicide that is the world’s most widely used herbicide since its introduction in the 1970s as a pre-plant, post-directed and post-harvest herbicide application with further technological developments leading to its use within glyphosate resistant crops (GRCs as of the 1990s. In countries around the world, weed shifts have accompanied weed management systems employing glyphosate products. The farmer actions and weed reactions that have contributed to these weed shifts will be discussed. Evidence of glyphosate-induced weed shifts has not yet been documented in Germany, but through consideration of the conditions that have lead to glyphosate-induced weed shifts elsewhere the outlook for Germany will be assessed. An ongoing research project will be introduced in which weed monitoring is being employed to find out if glyphosate-induced weed shifts can be identified in northeastern German arable farm fields and in which field experiments are also being conducted to further explore the reactions of weed communities and populations under the intensive application of glyphosate products.

  5. Competitive ability of black common bean genotypes with weeds

    Directory of Open Access Journals (Sweden)

    Gilcimar Adriano Vogt

    2013-10-01

    Full Text Available The morpho-physiologic characteristics of common bean plants can affect their competitive ability with weeds. The objective of this work was to evaluate the competitive ability of black bean genotypes with weeds. An experiment was carried out in the 2010/11 cropping season in Papanduva, SC, southern Brazil, in order to verify the variability of some plant characteristics among genotypes of common bean. The randomized block design was used, with four replications. Seven cultivars underwent the treatments: BRS Campeiro, CHP 01-238, CHP 01-239, Diamante Negro, BRS Supremo, BRS Valente, IPR Uirapuru, FTS Soberano, IPR Graúna, IPR Tiziu e IAC Diplomata. At 6, 14, 18, 25 and 32 days after emergence (DAE were evaluated plant height, ground cover by common bean plants, dry biomass of stems and leaves, and grain yield. In the 2011/12 cropping season the same cultivars were grown in the presence or absence of weeds, adopting similar methodology to the 2010/11. The losses of grain yield in black common bean genotypes due to weed interference ranged from 30.8% to 54.9%. There was a positive correlation between yield reduction promoted by the weed infestation and dry biomass produced by the weeds. In addition, there was a positive correlation between percentage of yield reduction due to the weed infestation and grain yield without weed interference. The characteristics evaluated did not estimate the competitive ability of black common bean genotypes with weeds.

  6. The definition of electro impulses used in weed control

    Directory of Open Access Journals (Sweden)

    Judaev I.V.

    2008-01-01

    Full Text Available In modern agriculture the use of chemicals and machines in weed control is not environmental and soil friendly. The use of electro impulses is offered to traditional ways of weed control. The researches done on technical characteristics of such operation and influence of these results on ecology gave picture that the use of electro impulses in weed control is harmless for environment and that is very effective. The basis for the technical project at designing of the electro impulse installation used with standard wheel tractor obtained data about values of electric energy doses that can make damage in various kinds of weeds.

  7. Critical Period of Weed Control in Aerobic Rice

    Directory of Open Access Journals (Sweden)

    M. P. Anwar

    2012-01-01

    Full Text Available Critical period of weed control is the foundation of integrated weed management and, hence, can be considered the first step to design weed control strategy. To determine critical period of weed control of aerobic rice, field trials were conducted during 2010/2011 at Universiti Putra Malaysia. A quantitative series of treatments comprising two components, (a increasing duration of weed interference and (b increasing length of weed-free period, were imposed. Critical period was determined through Logistic and Gompertz equations. Critical period varied between seasons; in main season, it started earlier and lasted longer, as compared to off-season. The onset of the critical period was found relatively stable between seasons, while the end was more variable. Critical period was determined as 7–49 days after seeding in off-season and 7–53 days in main season to achieve 95% of weed-free yield, and 23–40 days in off-season and 21–43 days in main season to achieve 90% of weed-free yield. Since 5% yield loss level is not practical from economic view point, a 10% yield loss may be considered excellent from economic view point. Therefore, aerobic rice should be kept weed-free during 21–43 days for better yield and higher economic return.

  8. Chemical and mechanical weed control in soybean (Glycine max

    Directory of Open Access Journals (Sweden)

    Weber, Jonas Felix

    2016-02-01

    Full Text Available In this study we investigated the possibility of chemical and mechanical weed control strategies in soybean. Soybean field experiments were carried out in 2013 and 2014 in Southern Germany. Five treatments including common herbicide mixtures and four mechanical weed control treatments, implementing a harrow and a hoe, were tested at different locations. In the herbicide experiments two treatments were applied by PRE emergence herbicides (metribuzin, clomazone, dimethenamid and metribuzin, flufenacet, clomazone and another two treatments were sprayed with a combination of PRE + POST emergence herbicides (metribuzin, flufenacet, thifensulfuron and pendimethalin, thifensulfuron, bentazone, cycloxydim. Furthermore, a POST herbicide treatment was implemented (thifensulfuron, bentazone, thifensulfuron and fluazifop-P-butyl. In the mechanical weed control experiments, treatments were: three times hoeing, PRE emergence harrowing plus three times hoeing, hoeing and harrowing in rotation or three times harrowing. In both experiments an untreated control was included. A 90% weed control efficacy and 23% yield increase was observed in the POST herbicide treatment. PRE + POST treatments resulted in 92% to 99% weed control efficiency and 15% yield increase compared to the untreated control. In the mechanical weed control experiments the combination of PRE emergence harrowing and POST emergence hoeing resulted in 82% weed control efficiency and 34% higher yield compared to the untreated control. Less weed control efficiency (72% was observed in the harrow treatment, leading to 20% higher yield compared to the control. The suitability of both strategies for implementation in “Integrated Weed Management” has been investigated.

  9. Determining treatment frequency for controlling weeds on traffic islands using chemical and non-chemical weed control

    DEFF Research Database (Denmark)

    Rask, Anne Merete; Larsen, S.U.; Andreasen, Christian

    2013-01-01

    Many public authorities rely on the use of non-chemical weed control methods, due to stringent restrictions on herbicide use in urban areas. However, these methods usually require more repeated treatments than chemical weed management, resulting in increased costs of weed management. In order...... to investigate the efficacy of four non-chemical weed control methods and glyphosate treatment, experiments were carried out on traffic islands in the growing seasons 2005 and 2006. Three trial sites were each divided into six treatment areas, which were either treated with glyphosate, flame, steam, hot air....../flame, hot water or left untreated. The treatments were carried out at regular, predetermined intervals throughout the growing season in 2004, whereas in 2005 and 2006 how many treatments that were required to keep weed cover below a predetermined acceptance level of 2% were investigated. Percentage weed...

  10. Weed-cover versus weed-removal management in olive orchards: influence on the carbon balance at the ecosystem scale

    Science.gov (United States)

    Chamizo, Sonia; Serrano-Ortiz, Penélope; Vicente-Vicente, José Luis; Sánchez-Cañete, Enrique P.; López-Ballesteros, Ana; Kowalski, Andrew S.

    2016-04-01

    Agriculture plays an important role in the C budget at the global scale. Traditional practices based on soil tillage and applying herbicides to remove weeds have caused damage to soils and led to important losses of soil organic C and increased CO2 emissions to the atmosphere. Changing trends from traditional agriculture to conservation agriculture practices may have an important role in both C and water budgets and the transformation of agriculture from C source to C sink. The objective of this study was to analyse the effect of two treatments, weed removal by herbicides versus weed cover conservation, on the C balance in an irrigated olive orchard in SE Spain. Measurements of CO2 exchange were made from October 2014 to September 2015 using two eddy covariance towers, one for each olive crop treatment. Results show that CO2 fluxes at the ecosystem scale were similar in the two treatments during initial conditions, prior to weed growth in the soils without herbicide application (October). During the first week, daily net ecosystem exchange (NEE) was close to zero in both treatments, with values ranging from 1.06 to -0.41 g C m-2 in the weed cover treatment, and from 0.76 to -0.69 g C m-2 in the weed removal treatment. As weed growth increased, higher net CO2 assimilation was found in the treatment with weed cover. In both treatments, maximum net CO2 assimilation was found in March, with a monthly NEE of -72 and -28 g C m-2 in the treatment with and without weed cover, respectively. In May, after the weeds were cut and left on the soil, a strong increase was observed in NEE in the treatment with weed cover due to decreased CO2 assimilation and increased respiration compared to the treatment without weed cover. Therefore, soil chamber measurements showed average respiration rates of 2.57 and 1.57 μmol m-2 s-2 in the weed cover and weed removal treatment, respectively. Finally, the highest monthly NEE was registered during July, with both treatments showing a similar

  11. Alteraciones morfo-histológicas en hojas de Solanum chenopodioides (Solanaceae, producidas por ácaros y dípteros minadores Morpho-histological alterations in leaves of Solanum chenopodioides (Solanaceae produced by mites and leaf miner diptera

    Directory of Open Access Journals (Sweden)

    Silvana D Del V. Figueroa

    2011-12-01

    Full Text Available Solanum chenopodioides Lam., conocida como "hierba mora", es una hierba o subarbusto ampliamente distribuido en Argentina y otras zonas de Sudamérica y es una maleza sumamente tóxica para el ganado. Sus hojas tienen propiedades medicinales y son utilizadas como sedante y en oftalmología. Es frecuente el ataque de sus hojas por ácaros fitófagos y por insectos minadores. El objetivo del presente trabajo fue analizar la morfología y la anatomía de las hojas en plantas sanas e infestadas por ácaros (Tetranychidae, Tetranychus sp. y dípteros minadores de la hoja (Agromyzidae. Los resultados muestran que el ataque de ambos agentes reduce significativamente el volumen del tejido fotosintético por excelencia. Así, se compromete el crecimiento, y por lo tanto la supervivencia de la especie. Aún más, en caso de ser utilizada como especie medicinal se afecta la calidad del principio activo.Solanum chenopodioides Lam., known as "nightshade", is a herb or subshrub widely distributed in Argentina and another zones of South America, and is a weed highly toxic to livestock. Its leaves have medicinal properties and are used as a sedative and in ophthalmology. The attack of its leaves by phytophagous mites and leafminer insects is frequent. The aim of this study was to analyze the morphology and the anatomy of the leaves of both healthy and infested plants by Tetranychidae, Tetranychus sp. mites and Agromyzidae leafminer diptera. The results show that the attack of both agents significantly reduces the amount of photosynthetic tissue par excellence. Thus, growth is compromised, and therefore the survival of the species. Moreover, when used as medicinal species, the quality the active principle is affected.

  12. Listado anotado de Solanum L. (Solanaceae) en el Perú

    DEFF Research Database (Denmark)

    Särkinen, Tiina; Baden, Maria; Gonzáles, Paúl

    2015-01-01

    The genus Solanum is among the most species-rich genera both of the Peruvian flora and of the tropical Andes in general. The present revised checklist treats 275 species of Solanum L., of which 252 are native, while 23 are introduced and/or cultivated. A total of 73 Solanum species (29% of native...

  13. AFLP analysis reveals a lack of phylogenetic structure within Solanum section Petota

    NARCIS (Netherlands)

    Jacobs, M.M.J.; Berg, van den R.G.; Vleeshouwers, V.; Visser, M.E.; Mank, R.; Sengers, M.; Hoekstra, R.; Vosman, B.

    2008-01-01

    Background The secondary genepool of our modern cultivated potato (Solanum tuberosum L.) consists of a large number of tuber-bearing wild Solanum species under Solanum section Petota. One of the major taxonomic problems in section Petota is that the series classification (as put forward by Hawkes) i

  14. Comparative speed of kill of sarolaner (Simparica™) and afoxolaner (NexGard®) against induced infestations of Amblyomma americanum on dogs

    OpenAIRE

    Six, Robert H.; Everett, William R.; Chapin, Sara; Mahabir, Sean P.

    2016-01-01

    Background The lone star tick, Amblyomma americanum, infests dogs and cats in North America and is the vector of the pathogens that cause monocytic and granulocytic ehrlichiosis in dogs and humans. A parasiticide’s speed of kill is important to minimize the direct and deleterious effects of tick infestation and especially to reduce the risk of transmission of tick-borne pathogens. In this study, speed of kill of a novel orally administered isoxazoline parasiticide, sarolaner (Simparica™ chewa...

  15. Presencia de Circulifer tenellus Baker y Beet mild curly top virus en maleza durante el invierno en el centro norte de México Circulifer tenellus Baker and Beet mild curly top virus presence in weeds during the winter in north-central Mexico

    Directory of Open Access Journals (Sweden)

    Rodolfo Velásquez-Valle

    2012-07-01

    Full Text Available Una de las enfermedades más importantes del chile para secado en el norte centro de México es la denominada amarillamientos del chile. Existe poca información acerca de la interacción entre el vector (Circulifer tenellus Baker, el Beet mild curly top virus y la maleza durante el invierno en esta región, consecuentemente el objetivo del trabajo fue identificar maleza de invierno que sirve como refugio para el vector y hospedero del virus en esta región. Entre enero y marzo de 2011 se muestrearon 26 manchones de maleza en los estados de Aguascalientes y Zacatecas. Se capturaron adultos de C. tenellus en 69.2% de los manchones de maleza muestreados; la mayoría (75.5% de los especímenes eran hembras. El Beet mild curly top fue identificado sólo 15.4% de los sitios de muestreo infectando especies de maleza como Eruca sativa, Reseda sp., Chenopodium sp. y Solanum rostratum L.One of the most important diseases of chili pepper for drying in the north-central Mexico is called yellowing of chili. There is little information about the interaction between the vector (Circulifer tenellus Baker, the Beet mild curly top virus and weeds during the winter in this region; therefore, the objective was to identify winter weeds that serve as are fuge for the vector and host of the virus in this region. Between January and March, 2011, 26 patches of weed were sampled in Aguascalientes and Zacatecas. Adult C. tenellus were captured in 69.2% of the weed sampled patches; most of the specimens were females (75.5%. Beet mild curly top was identified in only 15.4% of the sampling sites, infecting weed species suchas Eruca sativa, Reseda sp., Chenopodium sp. and Solanum rostratum L.

  16. The mitochondrial genome of Xiphinema americanum sensu stricto (Nematoda: Enoplea): considerable economization in the length and structural features of encoded genes.

    Science.gov (United States)

    He, Y; Jones, J; Armstrong, M; Lamberti, F; Moens, M

    2005-12-01

    The complete sequence of the mitochondrial genome of the plant parasitic nematode Xiphinema americanum sensu stricto has been determined. At 12626bp it is the smallest metazoan mitochondrial genome reported to date. Genes are transcribed from both strands. Genes coding for 12 proteins, 2 rRNAs and 17 putative tRNAs (with the tRNA-C, I, N, S1, S2 missing) are predicted from the sequence. The arrangement of genes within the X. americanum mitochondrial genome is unique and includes gene overlaps. Comparisons with the mtDNA of other nematodes show that the small size of the X. americanum mtDNA is due to a combination of factors. The two mitochondrial rRNA genes are considerably smaller than those of other nematodes, with most of the protein encoding and tRNA genes also slightly smaller. In addition, five tRNAs genes are absent, lengthy noncoding regions are not present in the mtDNA, and several gene overlaps are present.

  17. Herbicide Resistant Weeds: Do Economic Thresholds Still Have a Role in Weed Management?

    Science.gov (United States)

    Concern over the development of herbicide resistant weeds has prompted a closer look at the validity of using economic thresholds (ET) as a basis for making treatment decisions. In situations where herbicide resistance is suspected, growers are often advised to employ control measures to completely ...

  18. Post-directed weed control in bell peppers

    Science.gov (United States)

    Organic pepper (Capsicum annuum L.) producers need appropriate herbicides that can effectively provide post-emergent weed control. Research was conducted in southeast Oklahoma (Atoka County, Lane, OK) to determine the impact of a potential organic herbicide on weed control efficacy, crop injury, an...

  19. Weeding the Library Media Center Collections. Second Edition.

    Science.gov (United States)

    Buckingham, Betty Jo; And Others

    This second edition of guidelines for weeding school library media collections is addressed especially to elementary and secondary school library media centers and to community college and vocational school library resource centers in Iowa. This publication is designed for those who want weeding of all formats of materials and equipment (not just…

  20. Letting Go: How One Librarian Weeded a Children's Magazine Collection.

    Science.gov (United States)

    Bromann, Jennifer

    2002-01-01

    Describes the weeding process for children's magazines in a public library. Highlights include circulation statistics; cost effectiveness; online availability; shelving magazines by subject to try and increase their use; and a chart that lists reasons to keep and reasons to cancel subscriptions when weeding a periodical collection. (LRW)

  1. Weeding: An Experience at Columbus State Community College.

    Science.gov (United States)

    Fohl, Claire

    2001-01-01

    Discusses the difficulties inherent in de-selecting (or weeding) a library collection. Examines the issue of making sound judgments regarding what should be weeded and how. Suggests alternatives to discarding books, such as remote storage, selling them back to patrons, and sharing within a consortium. (NB)

  2. Designing, modeling and controlling a novel autonomous laser weeding system

    DEFF Research Database (Denmark)

    Shahrak Nadimi, Esmaeil; Andersson, Kim Johan; Jørgensen, Rasmus Nyholm

    2009-01-01

      Abstract: in this paper, the process of designing and developing a novel laser weeding test setup is explained. The main purpose of designing this system was to simulate the dynamic field conditions of a mobile vehicle capable of targeting weeds. This system consists of a rig containing three...

  3. Managing invasive plants in natural areas: Moving beyond weed control

    Science.gov (United States)

    Dean Pearson; Yvette Ortega

    2009-01-01

    Exotic invasive plants present one of the greatest challenges to natural resource management. These weeds can alter entire communities and ecosystems, substantially degrading important ecosystem services such as forage for wild and domestic herbivores, water and soil quality, recreational values, and wildlife habitat. Traditionally, weed management in natural areas has...

  4. Developing selection protocols for weed competitiveness in aerobic rice

    NARCIS (Netherlands)

    Zhao, D.L.; Atlin, G.N.; Bastiaans, L.; Spiertz, J.H.J.

    2006-01-01

    Aerobic rice production systems, wherein rice is dry-sown in non-puddled soil and grown as an upland crop, offer large water savings but are subject to severe weed infestation. Weed-competitive cultivars will be critical to the adoption of aerobic rice production by farmers. Breeding

  5. Aquatic weed control within an integrated water management framework.

    NARCIS (Netherlands)

    Querner, E.P.

    1993-01-01

    Aquatic weed control, carried out by the water boards in the Netherlands, is required to maintain sufficient discharge capacity of the surface water system. Weed control affects the conditions of both surface water and groundwater. The physically based model MOGROW was developed to simulate the flow

  6. Systematic design of an autonomous platform for robotic weeding

    NARCIS (Netherlands)

    Bakker, T.; Asselt, van C.J.; Bontsema, J.; Müller, J.; Straten, van G.

    2010-01-01

    The systematic design of an autonomous platform for robotic weeding research in arable farming is described. The long term objective of the project is the replacement of hand weeding in organic farming by a device working autonomously at field level. The distinguishing feature of the described desig

  7. Potential components for weed management in organic vegetable production systems

    Science.gov (United States)

    Organic vegetable production relies on a variety of tactics for preventing losses to crop yield and quality that result from weed interference. These include field selection, long term field management, cultivation practices, mulching, and manual weeding to name a few. The concept of "herbicides" th...

  8. Cover crop residue management for optimizing weed control

    NARCIS (Netherlands)

    Kruidhof, H.M.; Bastiaans, L.; Kropff, M.J.

    2009-01-01

    Although residue management seems a key factor in residue-mediated weed suppression, very few studies have systematically compared the influence of different residue management strategies on the establishment of crop and weed species. We evaluated the effect of several methods of pre-treatment and p

  9. Weed seed predation in organic and conventional fields

    DEFF Research Database (Denmark)

    Navntoft, S; Wratten, S D; Kristensen, K;

    2009-01-01

    Enhanced biological control of weed seeds may improve sustainability of agricultural production. Biological control due to seed predation may be higher in organic fields because organic production generally supports more seed predators. To investigate such a difference, weed seed predation was st...

  10. Managing weeds in organic farming systems: an ecological approach

    Science.gov (United States)

    Numerous investigators have concluded that improvements in weed management strategies that are minimally reliant on herbicides require the integration of multiple weed suppression tactics. However, the most cost-effective and efficacious ways to choose and combine tactics remain unclear. Here we sug...

  11. How to Identify and Control Water Weeds and Algae.

    Science.gov (United States)

    Applied Biochemists, Inc., Mequon, WI.

    Included in this guide to water management are general descriptions of algae, toxic algae, weed problems in lakes, ponds, and canals, and general discussions of mechanical, biological and chemical control methods. In addition, pictures, descriptions, and recommended control methods are given for algae, 6 types of floating weeds, 18 types of…

  12. Working the Educational Soil and Pulling Up Weeds

    Science.gov (United States)

    Riggins-Newby, Cheryl

    2005-01-01

    The job of an instructional leader, according to former Baltimore principal Deborah Wortham, is to be a gardener. School cultures left unattended, she says, sprout weeds that will eventually overwhelm the research-based programs, practices, and best efforts of teachers and administrators. The most aggressive and harmful educational weeds Wortham…

  13. Weed science research and funding: a call to action

    Science.gov (United States)

    Weed science has contributed much to agriculture, forestry and natural resource management over its history. However, if it is to remain relevant as a scientific discipline, it is long past time for weed scientists to take a step outside the “herbicide efficacy box” and address system-level issues i...

  14. Optimal weed management in crop rotations: incorporating economics is crucial

    NARCIS (Netherlands)

    Berg, van den F.; Gilligan, C.A.; Lemmen-Gerdessen, van J.C.; Gregoire, L.A.H.; Bosch, van den F.

    2010-01-01

    Although the effects of crop rotation sequence and length on weed population dynamics have been studied, it is not clear whether or not the best strategy, from a weed population dynamics point of view, is also the economic optimal strategy. It is also not clear which biological and economic paramete

  15. Prevention and control of weeds, pests and diseases

    NARCIS (Netherlands)

    Sukkel, W.; Hommes, M.

    2009-01-01

    Weed control still requires major investments of money and labour in organic arable farming and field vegetable cultivation. For this reason, current research is focused to a large extent on the development of weed control strategies. These incorporate prevention as well as mechanical methods, and c

  16. Working the Educational Soil and Pulling Up Weeds

    Science.gov (United States)

    Riggins-Newby, Cheryl

    2005-01-01

    The job of an instructional leader, according to former Baltimore principal Deborah Wortham, is to be a gardener. School cultures left unattended, she says, sprout weeds that will eventually overwhelm the research-based programs, practices, and best efforts of teachers and administrators. The most aggressive and harmful educational weeds Wortham…

  17. An Autonomous Robotic System for Mapping Weeds in Fields

    DEFF Research Database (Denmark)

    Hansen, Karl Damkjær; Garcia Ruiz, Francisco Jose; Kazmi, Wajahat

    2013-01-01

    The ASETA project develops theory and methods for robotic agricultural systems. In ASETA, unmanned aircraft and unmanned ground vehicles are used to automate the task of identifying and removing weeds in sugar beet fields. The framework for a working automatic robotic weeding system is presented...

  18. How to Identify and Control Water Weeds and Algae.

    Science.gov (United States)

    Applied Biochemists, Inc., Mequon, WI.

    Included in this guide to water management are general descriptions of algae, toxic algae, weed problems in lakes, ponds, and canals, and general discussions of mechanical, biological and chemical control methods. In addition, pictures, descriptions, and recommended control methods are given for algae, 6 types of floating weeds, 18 types of…

  19. Weed biocontrol in the EU: from serendipity to strategy

    Science.gov (United States)

    Biological control of weeds is a globally-recognized approach to the management of the worst invasive plants in the world. Unfortunately, accidental introduction of agents account for most weed biocontrol in the EU, but do include a number of current or emerging successes. From the redistribution of...

  20. Optimal weed management in crop rotations: incorporating economics is crucial

    NARCIS (Netherlands)

    Berg, van den F.; Gilligan, C.A.; Lemmen-Gerdessen, van J.C.; Gregoire, L.A.H.; Bosch, van den F.

    2010-01-01

    Although the effects of crop rotation sequence and length on weed population dynamics have been studied, it is not clear whether or not the best strategy, from a weed population dynamics point of view, is also the economic optimal strategy. It is also not clear which biological and economic

  1. Systematic design of an autonomous platform for robotic weeding

    NARCIS (Netherlands)

    Bakker, T.; Asselt, van C.J.; Bontsema, J.; Müller, J.; Straten, van G.

    2010-01-01

    The systematic design of an autonomous platform for robotic weeding research in arable farming is described. The long term objective of the project is the replacement of hand weeding in organic farming by a device working autonomously at field level. The distinguishing feature of the described

  2. Spirosolane-containing Solanum species and induction of congenital craniofacial malformations.

    Science.gov (United States)

    Keeler, R F; Baker, D C; Gaffield, W

    1990-01-01

    Comparison by GC analysis of purified alkaloid extracts of Solanum species revealed no measurable free solasodine, other spirosolanes, or any non-spirosolane steroidal alkaloid aglycones in unhydrolyzed total alkaloid fractions of fruit of Solanum elaeagnifolium Cav. (silverleaf nightshade), Solanum sarrachoides (S. villosum Lam.--hairy nightshade), Solanum dulcamara L. (European bittersweet nightshade) or Solanum melongena L. (eggplant). All alkaloidal material was apparently present as glycoside. Conversely, sprouts of Solanum tuberosum L. (potato) contained 67% of its alkaloids as glycosides, which was freed only upon hydrolysis with the remaining 33% present as free solanidine. GC/MS analysis of hydrolysates of purified extracts of the test Solanum species revealed that solasodine was a principal or sole aglycone of the alkaloid glycosides in each of the test species except Solanum tuberosum. In the latter, solanidine was the sole aglycone. Among the test species, exclusive of S. tuberosum, only S. dulcamara contained aglycones other than solasodine. In addition to solasodine, S. dulcamara contained appreciable amounts of an unknown spirosolane, an aglycone provisionally identified as soladulcidine. The induction of congenital craniofacial malformations in hamsters by high oral doses of the four Solanum species that contained mainly solasodine glycosides--S. elaeagnifolium, S. dulcamara, S. sarrachoides and S. melongena was compared to inductions of malformations by Solanum tuberosum, that contained mainly solanidane glycosides. Compared to controls, Solanum elaeagnifolium and Solanum dulcamara fruit both induced a high percentage incidence of deformed litters (20.4 and 16.3, respectively) that was statistically significant (P less than 0.001 level) while percentage incidence of deformed litters induced by Solanum sarrachoides and Solanum melongena fruit (9.5 and 7.6 respectively) were both higher than controls (3.4%), in neither case was the incidence

  3. Allelopatic potential of weeds under the minimalization of soil treatment

    Directory of Open Access Journals (Sweden)

    Mikhail A. Mazirov

    2014-01-01

    Full Text Available The content of water-dispersible phenol substances in rhizosphere both of annual and perennial species of weeds (Cirsium arvense, Sonchus arvensis increases under soil treatment minimalization. The higher content of phenol substances of researched weeds is defined in rhizosphere of Common Couch (Agropyrum repens. The absence of intensive anthropogenic treatment of plowing layer which accumulates the significant mass of weed’s roots in the cause of much more higher allelopathic potential of some species’ of weeds. The high level of saturation by weeds in agrophytocoenosis under non-tillage soil treatment is defines the competitiveness between certain sepsis’ of weeds, especially, at the beginning of the vegetation. In this case, increasing the secretion of phenol substances is one of the physiological screenings of such competitiveness.

  4. Spatial correlation between weed species densities and soil properties

    DEFF Research Database (Denmark)

    Walter, Mette; Christensen, Svend; Simmelsgaard, Svend Erik

    2002-01-01

    -correlated with the phosphorus content in the soil in all years. The density of Veronica spp. and Poa annua L. was negatively cross-correlated with pH in all three years. Other spatial cross-correlations that were found in this study were inconsistent over time or field site. The densities of some of the weed species were......The spatial cross-correlation between weed species densities and six soil properties within fields was analysed using cross-semivariograms. The survey was carried out in three successive years in two fields. The most consistent relationship between weed species density (numbers m−2) and soil...... spatially cross-correlated with more than one soil property. The results showed that the range of spatial dependence varied not only between fields, but also between weed species and soil properties, as well as between years. This study indicates that the weed pattern is field-specific and that the spatial...

  5. Spatial and Spectral Methods for Weed Detection and Localization

    Directory of Open Access Journals (Sweden)

    Truchetet Frédéric

    2002-01-01

    Full Text Available This study concerns the detection and localization of weed patches in order to improve the knowledge on weed-crop competition. A remote control aircraft provided with a camera allowed to obtain low cost and repetitive information. Different processings were involved to detect weed patches using spatial then spectral methods. First, a shift of colorimetric base allowed to separate the soil and plant pixels. Then, a specific algorithm including Gabor filter was applied to detect crop rows on the vegetation image. Weed patches were then deduced from the comparison of vegetation and crop images. Finally, the development of a multispectral acquisition device is introduced. First results for the discrimination of weeds and crops using the spectral properties are shown from laboratory tests. Application of neural networks were mostly studied.

  6. Applying a weed risk assessment approach to GM crops.

    Science.gov (United States)

    Keese, Paul K; Robold, Andrea V; Myers, Ruth C; Weisman, Sarah; Smith, Joe

    2014-12-01

    Current approaches to environmental risk assessment of genetically modified (GM) plants are modelled on chemical risk assessment methods, which have a strong focus on toxicity. There are additional types of harms posed by plants that have been extensively studied by weed scientists and incorporated into weed risk assessment methods. Weed risk assessment uses robust, validated methods that are widely applied to regulatory decision-making about potentially problematic plants. They are designed to encompass a broad variety of plant forms and traits in different environments, and can provide reliable conclusions even with limited data. The knowledge and experience that underpin weed risk assessment can be harnessed for environmental risk assessment of GM plants. A case study illustrates the application of the Australian post-border weed risk assessment approach to a representative GM plant. This approach is a valuable tool to identify potential risks from GM plants.

  7. The Effect of Laser Treatment as a Weed Control Method

    DEFF Research Database (Denmark)

    Mathiassen, Solvejg K; Bak, Thomas; Christensen, Svend

    2006-01-01

    for weed control, however, require a systematic investigation of the relationship between energy density and the biological effect on different weed species, growth stages, etc. This paper investigates the effect of laser treatment directed towards the apical meristems of selected weed species...... chickweed), Tripleurospermum inodorum (scentless mayweed) and Brassica napus (oilseed rape). The experiment showed that laser treatment of the apical meristems caused significant growth reduction and in some cases had lethal effects on the weed species. The biological efficacy of the laser control method...... was related to wavelength, exposure time, spot size and laser power. The efficacy also varied between the weed species. The results indicate that the efficacy of laser treatments can be improved by a more precise pointing of the laser beam towards the apical meristems and optimisation of the energy density...

  8. Restoring interventions: eco-sustainable weed control

    Directory of Open Access Journals (Sweden)

    Facciotto G

    2006-01-01

    Full Text Available The creation and enlargement of ecological networks is paramount to conserve plant biodiversity, to offer refuge to the local fauna and to improve the environment in general. Such networks intend to conserve areas of great natural value, to restore degraded areas and to link them physically through the creation of ecological corridors. The work described was carried out in order to improve and enlarge an ecological corridor within the experimental farm “Mezzi” of CRA-ISP at Casale Monferrato (AL - Italy. One of its bigger problems, weed control, was solved by increasing the planting density, by sowing herbaceous crops and mulching with woody chips.

  9. Benefits of Precision Farming Technologies for Mechanical Weed Control in Soybean and Sugar Beet—Comparison of Precision Hoeing with Conventional Mechanical Weed Control

    Directory of Open Access Journals (Sweden)

    Christoph Kunz

    2015-04-01

    Full Text Available Weed infestations and associated yield losses require effective weed control measures in soybean and sugar beet. Besides chemical weed control, mechanical weeding plays an important role in integrated weed management systems. Field experiments were conducted at three locations for soybean in 2013 and 2014 and at four locations for sugar beet in 2014 to investigate if automatic steering technologies for inter-row weed hoeing using a camera or RTK-GNSS increase weed control efficacy, efficiency and crop yield. Treatments using precision farming technologies were compared with conventional weed control strategies. Weed densities in the experiments ranged from 15 to 154 plants m−2 with Chenopodium album, Polygonum convolvulus, Polygonum aviculare, Matricaria chamomilla and Lamium purpureum being the most abundant species. Weed hoeing using automatic steering technologies reduced weed densities in soybean by 89% and in sugar beet by 87% compared to 85% weed control efficacy in soybean and sugar beet with conventional weeding systems. Speed of weed hoeing could be increased from 4 km h−1 with conventional hoes to 7 and 10 km·h−1, when automatic steering systems were used. Precision hoeing technologies increased soybean yield by 23% and sugar beet yield by 37%. After conventional hoeing and harrowing, soybean yields were increased by 28% and sugar beet yield by 26%.

  10. Weed management in tropical turfgrass areas: A review

    Directory of Open Access Journals (Sweden)

    Uddin Kamal M.D.

    2012-01-01

    Full Text Available Cultural practices promoting vigorous, environmentally friendly dense turf are discussed. These are the most important and least recognized means of preventing weed establishment and encroachment which includes appropriate propagation material selection, sanitation and cultivation, adjustment of planting time, manual weed control (hand pulling, hoeing and rouging, turfgrass selection to better compete with weed populations, applying physiological stresses, fertilizer management, moisture management, mowing, and irrigation with salt water. Cultural management of weed is important because it reduces dependence on synthetic pesticides. A healthy turfgrass stand has been reported to be the best defense against weed colonization, and can be accomplished by proper mowing, watering, and fertilization. Mowing height is the clearest and best-documented cultural factor and a lower mowing height is always associated with more weeds in the turfgrass. Split application of fertilizer at intervals throughout the growing period is recommended for warm season turfgrasses. The application of fertilizer during dormant periods or periods of low growth may encourage weed growth. Hand pulling and hoeing effectively control annual and biennial seedling weeds for small areas. Irrigation by saltwater has been one method used recently to effectively control grassy broadleaved and sedge weeds in salt-tolerant turfgrass species. Cultural weed management practices in turf might provide a first defense: however, relying only on cultural control measures may not be a good idea. An integrated approach of combining cultural practices and chemicals can complement each other and give flexibility to decision making. Research is needed on optimizing the choices of herbicide and/or cultural practices as part of an integrated management system for turfgrass.

  11. Weed species diversity in organic and integrated farming systems

    Directory of Open Access Journals (Sweden)

    Magdalena Jastrzębska

    2013-10-01

    Full Text Available Phytosociological data were collected in 1994–1996 in plots (relevés at the Research Station for Organic Farming and Conservation Breeding of the Polish Academy of Sciences in Popielno included in a large-area experiment conducted according to the concept and method proposed by Prof. S. Nawrocki. In a four-field crop rotation (root crops – spring barley undersown with red clover and grasses – red clover/grass mixture – winter triticale, each field was divided into two management units, organic and integrated. Data were collected in relevés by the Braun-Blanquet method, each year at the peak of the growing season. Weed abundance (% cover in cultivated fields and the number of weed species (species richness in crops were determined, which provided a basis for calculating the Shannon-Wiener indices of species diversity and evenness, and the Rényi profiles. The qualitative (species and quantitative structure of weed communities was compared using the Sørensen index. A total of 115 weed taxa (species, subspecies and varieties were identified in the examined agro-phytocenoses. Echinochloa crus-galli, Chenopodium album, Matricaria maritima subsp. inodora, Capsella bursa-pastoris, Thlaspi arvense and Stellaria media were the most abundant. Weed infestation was slightly higher in the organic farming system than in the integrated system. Organic farming contributed to higher weed species diversity in root crops, red clover/grass mixtures and winter triticale. Weed species richness was reduced in red clover/grass stands, while root crops and – to a lesser degree – spring barley undersown with red clover and grasses decreased weed species diversity. The species composition and in particular the quantitative structure of weeds were affected by crop species and cultivation regime rather than by the farming system. Weed communities of crops grown under organic and integrated farming systems were more similar with regard to species composition

  12. Moving integrated weed management from low level to a truly integrated and highly specific weed management system using advanced technologies

    NARCIS (Netherlands)

    Young, S.L.; Pitla, S.K.; Evert, Van F.K.; Schueller, J.K.; Pierce, F.J.; Liebman, Matt

    2017-01-01

    Integrated weed management (IWM) is one of the most commonly referred to approaches for sustainable and effective weed control in agriculture, yet it is not widely practiced, likely because current IWM systems fail to meet performance expectations of growers. The effectiveness and value of IWM syste

  13. RNAseq reveals weed-induced PIF3-like as a candidate target to manipulate weed stress response in soybean

    NARCIS (Netherlands)

    Horvath, David P; Hansen, Stephanie A; Moriles-Miller, Janet P; Pierik, Ronald; Yan, Changhui; Clay, David E; Scheffler, Brian; Clay, Sharon A

    Weeds reduce yield in soybeans (Glycine max) through incompletely defined mechanisms. The effects of weeds on the soybean transcriptome were evaluated in field conditions during four separate growing seasons. RNASeq data were collected from six biological samples of soybeans growing with or without

  14. RNAseq reveals weed-induced PIF3-like as a candidate target to manipulate weed stress response in soybean

    NARCIS (Netherlands)

    Horvath, David P; Hansen, Stephanie A; Moriles-Miller, Janet P; Pierik, Ronald; Yan, Changhui; Clay, David E; Scheffler, Brian; Clay, Sharon A

    2015-01-01

    Weeds reduce yield in soybeans (Glycine max) through incompletely defined mechanisms. The effects of weeds on the soybean transcriptome were evaluated in field conditions during four separate growing seasons. RNASeq data were collected from six biological samples of soybeans growing with or without

  15. The Effect of Weeds Interference Time and Plant Density on Weeds Control and Broad Bean (Vicia faba L. Yield

    Directory of Open Access Journals (Sweden)

    M Dabaghzadeh

    2016-10-01

    Full Text Available Introduction Broad bean (Vicia faba L. belongs to the Fabaceae family and is the most important protein plant in the world. Although broad bean used as cover crop is able to deal with weeds, but the evidence show that yield of the plant decreased 32-82% because of competition with weeds. Using crop density is one of the ecological approaches in weed management. Broad bean density can produce biomass, weed competition, seed yield and ultimately influence the economic yield. Many reports show that increasing crop density reduced negative effects of weeds. The aim of this experiment was to evaluate the effect of weeds interference and different densities of broad bean on density and biomass of weeds and broad bean seed yield. Materials and Methods The experiment was carried out as split plot in randomized complete block, with four replications, during 2009-2010 in a field experiment at Ramin Agricultural and Natural Resources University, Ahwaz. Weeds interference was investigated on 5 levels, including V5, V9, V13 broad-bean phonological stages, full season weeding and full season weeds interference selected as main plots, and broad-bean density on 3 levels: including 8, 11 and 14 plants m-2 as subplots. Density, dry weight and diversity of weeds and seed yield of broad bean were evaluated. Results and Discussion The results showed that the weeds including wild beet, field bindweed and mallow had the highest occurrence (26.35, 21.17 and 18.46 plants m-2 respectively in V9 broad-bean phonological stage, where the peak abundance of weeds was observed. The frequency of mallow, clover and yellow alfalfa were high until V5 broad-bean phonological stage, but in the next stages, they were replaced by other weeds and sorrel. It was also observed that the environmental factors can affect composition of weeds, for example, as the temperature increased in the early spring, an increase in the density of field bindweed was recorded. In the treatment of 8 plants

  16. Weeding of Academic Library Reference Collections: A Survey of Current Practice.

    Science.gov (United States)

    Engeldinger, Eugene A.

    1986-01-01

    Reports results of survey investigating aspects of weeding of materials in reference collections at 377 U.S. colleges and universities: existence of written policy or unwritten weeding practice; extent of weeding; frequency; what happens to discards; effect of shelf space, staff time, and use of materials on weeding decisions. (5 references) (EJS)

  17. Dynamics of weed populations : spatial pattern formation and implications for control

    NARCIS (Netherlands)

    Wallinga, J.

    1998-01-01

    Modelling studies were carried out to analyse spatio-temporal dynamics of annual weed populations and to identify the key factors that determine the long-term herbicide use of weed control programmes. Three different weed control programmes were studied.

    In the first weed

  18. Integrating management techniques to restore sites invaded by mile-a-minute weed, Persicaria perfoliata

    Science.gov (United States)

    Ellen C. Lake; Judith Hough-Goldstein; Vincent. D' Amico

    2014-01-01

    Efforts to suppress an invasive weed are often undertaken with the goal of facilitating the recovery of a diverse native plant community. In some cases, however, reduction in the abundance of the target weed results in an increase in other exotic weeds. Mile-a-minute weed (Persicaria perfoliata (L.) H. Gross (Polygonaceae)) is an annual vine from...

  19. 76 FR 39811 - International Center for Technology Assessment and the Center for Food Safety; Noxious Weed...

    Science.gov (United States)

    2011-07-07

    ... Assessment and the Center for Food Safety; Noxious Weed Status of Kentucky Bluegrass Genetically Engineered... engineered for tolerance to the herbicide glyphosate should not be listed as a Federal noxious weed and... noxious weeds. Our decision is based on our analysis of available scientific data, our weed risk...

  20. Weed Interference Effects on Leaves, Internode and Harvest Index of Dry Bean (Phaseolus vulgaris L.

    Directory of Open Access Journals (Sweden)

    Hossein GHAMARI

    2015-03-01

    Full Text Available The development of appropriate weed management strategies and efficient use of herbicides relies upon understanding weed-crop interactions. A field study was carried out to assess the effect of weed interference on leaves, internode and harvest index of dry bean (Phaseolus vulgaris L.. The experiment was established under a randomized complete block design with two types of weed interference treatments: plots with weeds and plots without weeds at different time intervals (0, 10, 20, 30, 40 and 50 days after crop emergence. The sigmoid Boltzmann model was used to quantify the crop traits as influenced by weed interference. Prolonged delays in weed removal reduced gradually the number of leaves of the crop. Weed interference decreased dry weight of leaves as well, so that the lowest value of it (33.49 g plant-1 was observed in full season during weed-infested treatment. Infestation of weeds affected the length of the crop internodes. While the weed interference duration increased, the length of the internodes decreased. Harvest index was also sensitive to weed competition. As the crop was kept weed-infested from the emergence for increasing periods of time, harvest index decreased to a value of 28.01%. A significant negative correlation between total biomass of weeds and dry bean traits (number of leaves, leaves dry weight, internode length and harvest index was observed. Therefore, weeds are able to adversely affect dry bean growth through constraining environmental resources and impairing leaves as the photosynthetic areas.

  1. Vinegar (20% acetic acid) broadcast application for broadleaf weed control in spring-transplanted onions

    Science.gov (United States)

    Organic weed control research was conducted in southeast Oklahoma to determine the effect of broadcast over-the-top applications of acetic acid (vinegar) on weed control efficacy, crop injury and onion yields. The experiment included 6 weed control treatments (2 application volumes, 2 hand-weeding ...

  2. Economics of supplemental weed control applications on spring-transplanted onions

    Science.gov (United States)

    Field research conducted to determine the relative benefits among alternative herbicides for weed control in onions (Allium cepa L.) measured weed control efficacy, impact of herbicides on crop injury, and the resulting weed competition on crop yields and marketable bulb size. Weed competition produ...

  3. Competitive suppression of weeds in a leek-celery intercropping system : An exploration of functional biodiversity

    NARCIS (Netherlands)

    Baumann, D.T.

    2001-01-01

    Late-emerging weeds, although not directly damaging the crop, may cause long-term weed management problems due to excessive seed production. Particularly in weak competitive crops with high quality requirements, such as leek, financial losses due to weed competition or weed management costs can be c

  4. Lawn Weeds and Their Control. North Central Regional Extension Publication No. 26.

    Science.gov (United States)

    Purdue Univ., Lafayette, IN. Cooperative Extension Service.

    This publication discusses lawn weed control for the twelve state north central region of the country. Written for use by homeowners, the publication focuses on weed identification and proper herbicide selection and application. Identification of weeds and safe and appropriate herbicide use are emphasized. Forty-six weed and turf plants are…

  5. Lawn Weeds and Their Control. North Central Regional Extension Publication No. 26.

    Science.gov (United States)

    Purdue Univ., Lafayette, IN. Cooperative Extension Service.

    This publication discusses lawn weed control for the twelve state north central region of the country. Written for use by homeowners, the publication focuses on weed identification and proper herbicide selection and application. Identification of weeds and safe and appropriate herbicide use are emphasized. Forty-six weed and turf plants are…

  6. Comparison of three tillage intensities on grass weed occurrence in cereal rotation

    OpenAIRE

    Salonen, Jukka

    2009-01-01

    In general, a rapid infestation of grass weeds was demonstrated in the plots with direct drilling. On the contrary, hardly any grass weeds infested the ploughed plots. The proportion between grass weeds and broad-leaved weeds differed in three tillage systems.

  7. Use of weeds as traditional vegetables in Shurugwi District, Zimbabwe.

    Science.gov (United States)

    Maroyi, Alfred

    2013-08-20

    Most agricultural weeds are usually regarded as undesirable and targeted for eradication. However, weeds are useful to human beings as food and traditional medicines. Few studies have been done to document the uses of weeds as traditional vegetables. This study was therefore, done to document indigenous knowledge related to the diversity and use of agricultural weeds as traditional vegetables in Shurugwi District, Zimbabwe, emphasizing their role in food security and livelihoods of the local people. Semi-structured interviews, observation and guided field walks with 147 participants were employed between December 2011 and January 2012 to obtain ethnobotanical data on the use of edible weeds as traditional vegetables. Based on ethnobotanical information provided by the participants, botanical specimens were collected, numbered, pressed and dried for identification. A total of 21 edible weeds belonging to 11 families and 15 genera, mostly from Amaranthaceae (19%), Asteraceae and Tiliaceae (14.3%), Capparaceae, Cucurbitaceae and Solanaceae (9.5% each) were identified. Of the documented edible weeds, 52.4% are indigenous while 47.6% are exotic to Zimbabwe; either semi-cultivated or growing naturally as agricultural weeds in farmlands, fallow land and home gardens. Among the main uses of edible weeds were leafy vegetables (81%), followed by edible fruits (19%), edible corms (9.5%), edible flowers and seeds (4.8% each). The most important edible weeds were Cleome gynandra, cited by 93.9% of the participants, Cucumis metuliferus (90.5%), Cucumis anguria (87.8%), Corchorus tridens (50.3%) and Amaranthus hybridus (39.5%). All edible weeds were available during rainy and harvest period with Cleome gynandra, Corchorus tridens, Cucumis anguria, Cucumis metuliferus and Moringa oleifera also available during the dry season, enabling households to obtain food outputs in different times of the year. The importance of edible weeds for local livelihoods was ubiquitously perceived

  8. Evaluation of three manually operated weeding devices.

    Science.gov (United States)

    Tewari, V K; Datta, R K; Murthy, A S

    1991-04-01

    Performance of three manually operated weeders was evaluated from ergonomics and mechanical considerations. Three operators were selected for laboratory and field trials; they represented the 5th, 50th and 95th percentiles of the operator population. Laboratory tests were conducted in a psychometric chamber to study physiological response under varying load and environmental conditions. From the data, relationships between energy expenditure rate and oxygen consumption rate vs heart rate were established. Field tests were carried out with the three weeders in a farm with Arhar crop (Cajannus Cajan L.) during August-September, when the average ambient temperature and relative humidity were 36 degrees C and 82% respectively. The results of this investigation indicated that weeding with the indigenous tools of a 'khurpi' and a spade and with the improved tool (3-tine hoe) could be rated as 'moderately heavy' work. However, a 'khurpi' demanded less energy expenditure than a 3-tine hoe followed by a spade. The squatting posture with a 'khurpi' appeared to be more comfortable than the standing posture with about 145 degrees erect position for the 3-tine hoe, followed by the standing posture with about 108 degrees erect position with the spade. For consideration of higher output, the order was spade, 3-tine hoe and 'khurpi', For weeding efficiency the trend was, however, just the reverse.

  9. Natural diversity of potato (Solanum tuberosum) invertases

    Science.gov (United States)

    2010-01-01

    Background Invertases are ubiquitous enzymes that irreversibly cleave sucrose into fructose and glucose. Plant invertases play important roles in carbohydrate metabolism, plant development, and biotic and abiotic stress responses. In potato (Solanum tuberosum), invertases are involved in 'cold-induced sweetening' of tubers, an adaptive response to cold stress, which negatively affects the quality of potato chips and French fries. Linkage and association studies have identified quantitative trait loci (QTL) for tuber sugar content and chip quality that colocalize with three independent potato invertase loci, which together encode five invertase genes. The role of natural allelic variation of these genes in controlling the variation of tuber sugar content in different genotypes is unknown. Results For functional studies on natural variants of five potato invertase genes we cloned and sequenced 193 full-length cDNAs from six heterozygous individuals (three tetraploid and three diploid). Eleven, thirteen, ten, twelve and nine different cDNA alleles were obtained for the genes Pain-1, InvGE, InvGF, InvCD141 and InvCD111, respectively. Allelic cDNA sequences differed from each other by 4 to 9%, and most were genotype specific. Additional variation was identified by single nucleotide polymorphism (SNP) analysis in an association-mapping population of 219 tetraploid individuals. Haplotype modeling revealed two to three major haplotypes besides a larger number of minor frequency haplotypes. cDNA alleles associated with chip quality, tuber starch content and starch yield were identified. Conclusions Very high natural allelic variation was uncovered in a set of five potato invertase genes. This variability is a consequence of the cultivated potato's reproductive biology. Some of the structural variation found might underlie functional variation that influences important agronomic traits such as tuber sugar content. The associations found between specific invertase alleles and

  10. Wallowa Canyonlands Weed Partnership : Completion Report November 19, 2009

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Mark C.; Ketchum, Sarah

    2008-12-30

    Noxious weeds threaten fish and wildlife habitat by contributing to increased sedimentation rates, diminishing riparian structure and function, and reducing forage quality and quantity. Wallowa Resources Wallowa Canyonlands Partnership (WCP) protects the unique ecological and economic values of the Hells Canyon grasslands along lower Joseph Creek, the lower Grande Ronde and Imnaha Rivers from invasion and degradation by noxious weeds using Integrated Weed Management techniques. Objectives of this grant were to inventory and map high priority weeds, coordinate treatment of those weeds, release and monitor bio-control agents, educate the public as to the dangers of noxious weeds and how to deal with them, and restore lands to productive plant communities after treatment. With collaborative help from partners, WCP inventoried {approx} 215,000 upland acres and 52.2 miles of riparian habitat, released bio-controls at 23 sites, and educated the public through posters, weed profiles, newspaper articles, and radio advertisements. Additionally, WCP used other sources of funding to finance the treatment of 1,802 acres during the course of this grant.

  11. Allelobiosis in the interference of allelopathic wheat with weeds.

    Science.gov (United States)

    Li, Yong-Hua; Xia, Zhi-Chao; Kong, Chui-Hua

    2016-11-01

    Plants may chemically affect the performance of neighbouring plants through allelopathy, allelobiosis or both. In spite of increasing knowledge about allelobiosis, defined as the signalling interactions mediated by non-toxic chemicals involved in plant-plant interactions, the phenomenon has received relatively little attention in the scientific literature. This study examined the role of allelobiosis in the interference of allelopathic wheat with weeds. Allelopathic wheat inhibited the growth of five weed species tested, and the allelochemical (2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one) production of wheat was elicited in the presence of these weeds, even with root segregation. The inhibition and allelochemical levels varied greatly with the mixed species density. Increased inhibition and allelochemical levels occurred at low and medium densities but declined at high densities. All the root exudates and their components of jasmonic acid and salicylic acid from five weeds stimulated allelochemical production. Furthermore, jasmonic acid and salicylic acid were found in plants, root exudates and rhizosphere soils, regardless of weed species, indicating their participation in the signalling interactions defined as allelobiosis. Through root-secreted chemical signals, allelopathic wheat can detect competing weeds and respond by increased allelochemical levels to inhibit them, providing an advantage for its own growth. Allelopathy and allelobiosis are two probably inseparable processes that occur together in wheat-weed chemical interactions. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  12. Capabilities of unmanned aircraft vehicles for low altitude weed detection

    Science.gov (United States)

    Pflanz, Michael; Nordmeyer, Henning

    2014-05-01

    Sustainable crop production and food security require a consumer and environmental safe plant protection. It is recently known, that precise weed monitoring approaches could help apply pesticides corresponding to field variability. In this regard the site-specific weed management may contribute to an application of herbicides with higher ecologically aware and economical savings. First attempts of precision agriculture date back to the 1980's. Since that time, remote sensing from satellites or manned aircrafts have been investigated and used in agricultural practice, but are currently inadequate for the separation of weeds in an early growth stage from cultivated plants. In contrast, low-cost image capturing at low altitude from unmanned aircraft vehicles (UAV) provides higher spatial resolution and almost real-time processing. Particularly, rotary-wing aircrafts are suitable for precise path or stationary flight. This minimises motion blur and provides better image overlapping for stitching and mapping procedures. Through improved image analyses and the recent increase in the availability of microcontrollers and powerful batteries for UAVs, it can be expected that the spatial mapping of weeds will be enhanced in the future. A six rotors microcopter was equipped with a modified RGB camera taking images from agricultural fields. The hexacopter operates within predefined pathways at adjusted altitudes (from 5 to 10 m) by using GPS navigation. Different scenarios of optical weed detection have been carried out regarding to variable altitude, image resolution, weed and crop growth stages. Our experiences showed high capabilities for site-specific weed control. Image analyses with regard to recognition of weed patches can be used to adapt herbicide application to varying weed occurrence across a field.

  13. Evaluation of DEET and eight essential oils for repellency against nymphs of the lone star tick, Amblyomma americanum (Acari: Ixodidae).

    Science.gov (United States)

    Meng, Hao; Li, Andrew Y; Costa Junior, Livio M; Castro-Arellano, Ivan; Liu, Jingze

    2016-02-01

    DEET and Eight commercially available essential oils (oregano, clove, thyme, vetiver, sandalwood, cinnamon, cedarwood, and peppermint) were evaluated for repellency against host-seeking nymphs of the lone star tick, Amblyomma americanum. Concentration-repellency response was established using the vertical paper bioassay technique for each essential oil and compared with that of N,N-diethyl-3-methyl benzamide (DEET), a standard repellent compound present in many commercial repellent formulations. The effective concentration of DEET that repels 50% of ticks (EC50) was estimated at 0.02 mg/cm(2), while EC50s of the essential oils fall between 0.113 and 0.297 mg/cm(2). Based on EC50 estimates, oregano essential oil was the most effective among all essential oils tested, followed by clove, thyme, vetiver, sandalwood, cinnamon, cedarwood, and peppermint oils. None of the tested essential oils demonstrated a level of tick repellency found with DEET. Results from this study illustrated the challenge in search for more effective natural tick repellents.

  14. Neuronal projections from the Haller's organ and palp sensilla to the synganglion of Amblyomma americanum§.

    Science.gov (United States)

    Borges, Lígia Miranda Ferreira; Li, Andrew Yongsheng; Olafson, Pia Untalan; Renthal, Robert; Bauchan, Gary Roy; Lohmeyer, Kimberly Hutchison; León, Adalberto Angel Pérez de

    2016-06-14

    The present study was conducted to elucidate the neuronal pathways between peripheral olfactory and taste sensilla and the synganglion in an Ixodidae tick species. The tarsus of the front legs (olfactory nerves) and the fourth palpal segment (gustatory nerves) of unfed Amblyomma americanum males and females were excised. A neuronal tracer, dextran tetramethylrhodamine, was used for filling of the sensory neurons. The synganglion preparations were examined using a confocal microscope. Neuronal arborizations from the Haller's organ were confined to the olfactory lobes and the first pedal ganglion. The estimated number of olfactory glomeruli ranged from 16 to 22 per olfactory lobe in the females. The number of glomeruli was not counted in males because they were densely packed. Sensory neurons associated with sensilla at the distal end of the palpal organ projected into the palpal ganglion in the synganglion through the palpal nerve. Gustatory sensory neurons associated with palpal sensilla projected into a commissure with several bulges, which are confined in the palpal ganglion. The findings of distinct projection patterns of sensory neurons associated with the Haller's organ and palpal organ in the lone star tick from this study advanced our knowledge on mechanisms of sensory information processing in ticks.

  15. Influência do tipo e da quantidade de resíduos vegetais na emergência de plantas daninhas Influence of type and amount of crop residues on weed emergence

    Directory of Open Access Journals (Sweden)

    N.M. Correia

    2006-06-01

    Full Text Available Com o objetivo de avaliar os efeitos da semeadura no outono/inverno de diferentes espécies: sorgo de cobertura (Sorghum bicolor x Sorghum sudanense 'híbrido Cober Exp', milheto forrageiro (Pennisetum americanum 'var. BN2', capim-pé-de-galinha (Eleusine coracana e braquiária (Brachiaria brizantha para formação de palha (nas quantidades de 3,0 e 5,5 t ha¹, na emergência de plantas daninhas, foi conduzido experimento no ano agrícola 2003/04, na fazenda Três Marcos, em Uberlândia, MG. Foi mantida uma testemunha como tratamento adicional, sem cobertura com restos vegetais. A composição específica e as densidades populacionais das comunidades infestantes foram influenciadas pelos sistemas de produção de cobertura morta. A emergência das plantas daninhas foi menor nas coberturas de sorgo e braquiária e nos maiores níveis de palha. O número de plântulas emergidas de Bidens pilosa, Amaranthus spp., Commelina benghalensis, Leucas martinicensis e gramíneas foi inibido pelas coberturas, enquanto para Chamaesyce spp. os resíduos contribuíram para incremento na sua emergência.To evaluate the effects on weed emergence of autumn/winter sowing of different species [sorghum (Sorghum bicolor x Sorghum sudanense 'Cober Exp hybrid', forage millet (Pennisetum americanum 'var. BN2', finger millet (Eleusine coracana and St Lucia grass (Brachiaria brizantha, for mulch formation (at rates of 3.0 and 5.5 t ha-1, an experiment was carried out in the agricultural year 2003/2004, in Uberlândia, Minas Gerais, Brazil. The specific composition and population densities of the infesting community were influenced by the mulch production systems. Weed emergence was minor under sorghum and Sta Lucia grass cover and in greater amounts of straw. Straw cover inhibited the emergence of seedlings of Bidens pilosa, Amaranthus spp., Commelina benghalensis, Leucas martinicensis and grasses and stimulated the emergence of Chamaesyce spp.

  16. Weed seed germination in winter cereals under contrasting tillage systems

    DEFF Research Database (Denmark)

    Scherner, Ananda

    2015-01-01

    to accumulate in the top soil layer and timing of herbicide applications sometimes seems to target the emergence pattern of these weeds poorly. In contrast to the management of most diseases and pests, weed management should be considered in a time frame. The abilities to produce above and below ground...... improving the targeting of direct control tactics, whatever they are chemical and non-chemical. This should ensure non-excessive use of herbicides and thus follow the principles of IPM. More specifically, focus should be on the soil layers from which the weed seeds predominantly emerge, their rate...

  17. Solanum sect. Petota in Guatemala: taxonomy and genetic resources

    NARCIS (Netherlands)

    Spooner, D.M.; Hoekstra, R.; Berg, van den R.G.; Martinez, V.

    1998-01-01

    There are five wild potato species in Guatemala:Solanum agrimonifolium,S. bulbocastanum,S. clarum,S. demissum, andS. morelliforme. We conducted a collecting expedition there from September 11 to November 5, 1995. The goals of the expedition were to gather field data for taxonomic studies of the five

  18. Evaluation of genetic stability in cryopreserved Solanum tuberosum

    African Journals Online (AJOL)

    STORAGESEVER

    2008-08-18

    Aug 18, 2008 ... the genetic stability of potato (Solanum tuberosum L.) plantlets of the cultivars Agria ... detect if there were probably any changes in the level of polyploidy. .... Phor-All buffer (10 mM Tris-HAc pH 7.5, 10 mM MgAc, 50 mM KAc,.

  19. Resistance to Erwina spp. in potato (Solanum tuberosum L.).

    NARCIS (Netherlands)

    Allefs, J.J.H.M.

    1995-01-01

    Blackleg is a disease of potato, Solanum tuberosum , which is caused by the bacteria Erwinia carotovora subsp. carotovora ( Ecc ), E.c. subsp. atroseptica ( Eca ) or E . chrysanthemi (Ech). Incidence of blackleg negatively affects the quality of seed potatoes. Disease control relies on phytosanitary

  20. Solanum carolinense L. en Pimpinella peregrina L. in Nederland

    NARCIS (Netherlands)

    Dirkse, Gerard M.; Holverda, Wout J.; Hochstenbach, Sophie M.H.; Reijerse, Fons A.I.

    2007-01-01

    Solanum carolinense L., een kniehoog bestekeld en met sterharen bezet, bleekblauw bloeiend struikje is recent op een aantal plekken aan vooral de Waal gevonden. De eerste vondst dateert echter al van 1983 bij Ochten, maar de soort werd toen niet herkend. Gebleken is dat de populaties zich in ieder g

  1. Pharmacological activities of Solanum melongena Linn. (Brinjal plant)

    OpenAIRE

    Mitali Das; Nilotpal Barua

    2013-01-01

    Solanum melongena Linn. is a herbaceous plant, with coarsely lobed leaves, white to purple flowers, fruit is berry and are grown mainly for food and medicinal purposes. The plant contains flavonoids, tropane, glycoalkaloids, arginine, lanosterol, gramisterol, aspartic acid as important constituents. The plant is reported to have analgesic, antipyretic, antioxidant, anti-inflammatory, antiasthmatic, hypolipidemic, hypotensive, antiplatelet, intraocular pressure reducing, CNS depressant and ana...

  2. Role of Solanum dulcamara L. in Potato Late Blight Epidemiology

    NARCIS (Netherlands)

    Golas, T.M.; Weerden, van der G.M.; Berg, van den R.G.; Mariani, C.; Allefs, J.J.H.M.

    2010-01-01

    Four sites with naturally growing Solanum dulcamara were surveyed during 2006 and 2007 for the presence of late blight. Despite 2 years of observations, no late blight was detected among natural populations of bittersweet. Nevertheless, repeated infections occurred on few S. dulcamara plants from a

  3. 不同种植方式对玉米田杂草群落及生长发育的影响%Effect of different planting methods on weed group and weed growth and development in corn field

    Institute of Scientific and Technical Information of China (English)

    刘芳; 殷红; 郭范顺; 李建东; 燕雪飞; 王国娇; 韦岩

    2009-01-01

    Through inter-species of corn and alfalfa and cor n-species comparison, discussed the impact of grow alfalfa to weed group and we ed growth and development in corn fields. The result indicated that, the Echinochloa crusgalli and Polygonum orientale important value were higher in corn-species, were the idominant species, in in ter-species of corn and alfalfa field the idominant species were the Polygonu m orientale, Echinochloa crusgalli, Chenopodium album, Amaranthus retroflexus L and Solanum nigrum Linn, Abutilon theophrasti Medic; Various growth s tages in corn, inter species of alfalfa the weed biomass was lower than the corn species, most of the time, weed height was lower than the corn species; Inter- species of corn and alfalfa field, compared with the corn-species, ear length, ear rows, row rows, ear weight, grain weight per spike, weight of hundred grains and yield increased by 6.6%,7.6%,2.2%,12.28%,9.9%,7.8%,4.3%. Inter- species of alfalfa can control the number of weeds, inhibit weed biomass increas ed, increase corn production through of the alfalfa. This study could provide sc ientific bases for controlling weeds, drought resistance and water retention in corn field applied by exotic green manure plants.%采取随机区组试验,根据农田杂草群落的生态学原理 ,运用生态学方法,通过玉米苜蓿间种与玉米清种相对照,探讨了间种抗旱植物苜蓿对玉米田杂草群落与生长发育的影响.结果表明:清种玉米田中稗草和红蓼的重要值较高,为优势种,间种苜蓿田中的优势种有红蓼、稗草、苘麻、反枝苋、龙葵、藜;在玉米各生育期,间种苜蓿田中的杂草生物量均低于清种玉米田处理,杂草株高大部分低于清种玉米处理;间种苜蓿穗长、穗行数、行粒数、穗重、穗粒重、百粒重和产量较清种玉米分别增加了6.6%、7.6%、2.2%、 12.28%、9.9%、7.8%和4.3%.认为间种苜蓿能够控制杂草数量,抑制杂草生物量增加,苜蓿

  4. Microbial weeds in hypersaline habitats: the enigma of the weed-like Haloferax mediterranei

    Science.gov (United States)

    Oren, Aharon; Hallsworth, John E.

    2014-10-01

    Heterotrophic prokaryotic communities that inhabit saltern crystallizer ponds are typically dominated by two species, the archaeon Haloquadratum walsbyi and the bacterium Salinibacter ruber, regardless of location. These organisms behave as 'microbial weeds' as defined by Cray et al. (Microb Biotechnol6: 453–492, 2013) that possess the biological traits required to dominate the microbiology of these open habitats. Here, we discuss the enigma of the less abundant Haloferax mediterranei, an archaeon that grows faster than any other, comparable extreme halophile. It has a wide window for salt tolerance, can grow on simple as well as on complex substrates and degrade polymeric substances, has different modes of anaerobic growth, can accumulate storage polymers, produces gas vesicles, and excretes halocins capable of killing other Archaea. Therefore, Hfx. mediterranei is apparently more qualified as a 'microbial weed' than Haloquadratum and Salinibacter. However, the former differs because it produces carotenoid pigments only in the lower salinity range and lacks energy-generating retinal-based, light-driven ion pumps such as bacteriorhodopsin and halorhodopsin. We discuss these observations in relation to microbial weed biology in, and the open-habitat ecology of, hypersaline systems.

  5. Inbreeding in horsenettle (Solanum carolinense) alters night-time volatile emissions that guide oviposition by Manduca sexta moths.

    Science.gov (United States)

    Kariyat, Rupesh R; Mauck, Kerry E; Balogh, Christopher M; Stephenson, Andrew G; Mescher, Mark C; De Moraes, Consuelo M

    2013-04-22

    Plant volatiles serve as key foraging and oviposition cues for insect herbivores as well as their natural enemies, but little is known about how genetic variation within plant populations influences volatile-mediated interactions among plants and insects. Here, we explore how inbred and outbred plants from three maternal families of the native weed horsenettle (Solanum carolinense) vary in the emission of volatile organic compounds during the dark phase of the photoperiod, and the effects of this variation on the oviposition preferences of Manduca sexta moths, whose larvae are specialist herbivores of Solanaceae. Compared with inbred plants, outbred plants consistently released more total volatiles at night and more individual compounds-including some previously reported to repel moths and attract predators. Female moths overwhelmingly chose to lay eggs on inbred (versus outbred) plants, and this preference persisted when olfactory cues were presented in the absence of visual and contact cues. These results are consistent with our previous findings that inbred plants recruit more herbivores and suffer greater herbivory under field conditions. Furthermore, they suggest that constitutive volatiles released during the dark portion of the photoperiod can convey accurate information about plant defence status (and/or other aspects of host plant quality) to foraging herbivores.

  6. Turning Waste into Value: Nanosized Natural Plant Materials of Solanum incanum L. and Pterocarpus erinaceus Poir with Promising Antimicrobial Activities.

    Science.gov (United States)

    Griffin, Sharoon; Tittikpina, Nassifatou Koko; Al-Marby, Adel; Alkhayer, Reem; Denezhkin, Polina; Witek, Karolina; Gbogbo, Koffi Apeti; Batawila, Komlan; Duval, Raphaël Emmanuel; Nasim, Muhammad Jawad; Awadh-Ali, Nasser A; Kirsch, Gilbert; Chaimbault, Patrick; Schäfer, Karl-Herbert; Keck, Cornelia M; Handzlik, Jadwiga; Jacob, Claus

    2016-04-19

    Numerous plants are known to exhibit considerable biological activities in the fields of medicine and agriculture, yet access to their active ingredients is often complicated, cumbersome and expensive. As a consequence, many plants harbouring potential drugs or green phyto-protectants go largely unnoticed, especially in poorer countries which, at the same time, are in desperate need of antimicrobial agents. As in the case of plants such as the Jericho tomato, Solanum incanum, and the common African tree Pterocarpus erinaceus, nanosizing of original plant materials may provide an interesting alternative to extensive extraction and isolation procedures. Indeed, it is straightforward to obtain considerable amounts of such common, often weed-like plants, and to mill the dried material to more or less uniform particles of microscopic and nanoscopic size. These particles exhibit activity against Steinernema feltiae or Escherichia coli, which is comparable to the ones seen for processed extracts of the same, respective plants. As S. feltiae is used as a model nematode indicative of possible phyto-protective uses in the agricultural arena, these findings also showcase the potential of nanosizing of crude "waste" plant materials for specific practical applications, especially-but not exclusively-in developing countries lacking a more sophisticated industrial infrastructure.

  7. Turning Waste into Value: Nanosized Natural Plant Materials of Solanum incanum L. and Pterocarpus erinaceus Poir with Promising Antimicrobial Activities

    Directory of Open Access Journals (Sweden)

    Sharoon Griffin

    2016-04-01

    Full Text Available Numerous plants are known to exhibit considerable biological activities in the fields of medicine and agriculture, yet access to their active ingredients is often complicated, cumbersome and expensive. As a consequence, many plants harbouring potential drugs or green phyto-protectants go largely unnoticed, especially in poorer countries which, at the same time, are in desperate need of antimicrobial agents. As in the case of plants such as the Jericho tomato, Solanum incanum, and the common African tree Pterocarpus erinaceus, nanosizing of original plant materials may provide an interesting alternative to extensive extraction and isolation procedures. Indeed, it is straightforward to obtain considerable amounts of such common, often weed-like plants, and to mill the dried material to more or less uniform particles of microscopic and nanoscopic size. These particles exhibit activity against Steinernema feltiae or Escherichia coli, which is comparable to the ones seen for processed extracts of the same, respective plants. As S. feltiae is used as a model nematode indicative of possible phyto-protective uses in the agricultural arena, these findings also showcase the potential of nanosizing of crude “waste” plant materials for specific practical applications, especially—but not exclusively—in developing countries lacking a more sophisticated industrial infrastructure.

  8. Control of aquatic weeds through pollutant reduction and weed utilization: a weed management approach in the lower Kafue River of Zambia

    Science.gov (United States)

    Sinkala, Thomson; Mwase, Enala T.; Mwala, Mick

    The aquatic weed situation in the Kafue River in Zambia continues to be a major challenge to the sustainable utilization of the water resources of the river. The general methods for managing the weeds, especially the water hyacinth, include use of bio-agents, chemicals, mechanical and physical approaches. These have had very little impact. This paper reports on a project that is investigating weed management strategies which involve use of cleaner production (CP) approach and the utilization of the weed for economic purposes. In addition, the ecological implications of these methods are being assessed. Effluent assessments indicated that apart from nitrates and phosphates, other effluent parameters met the Environmental Council of Zambia standards. Results further show that all the 24 areas surveyed for CP have uncontrolled socio-economic activities which generate both point and non-point sources of pollution that enter the water bodies. To minimize pollution, efforts include devising policy and technical strategies with the involvement of the affected riparian community. Production of mushroom by the communities using the water hyacinth substrate has been demonstrated. Up to 2.1 kg of mushroom was harvested from a single flush over a period of 4-5 weeks. Vegetables grown on soils treated with water hyacinth manure performed better than those grown using commercial fertiliser. The economics of the production are however, yet to be confirmed. If weed usage is proven economically and ecologically viable, the riverine community is envisaged to play a big role in aquatic weed management. High numbers of invertebrates known to be sensitive to pollution have been recorded in the weed-infested Kafue River implying that the water is of “good” quality for these aquatic invertebrates. This observed quality of water may be due to water hyacinth playing a role by sieving pollutants from the river.

  9. Inbreeding, heterosis, fertility, plasmon differentiation and Phytophthora resistance in Solanum verrucosum Schlechtd., and some interspecific crosses in Solanum

    NARCIS (Netherlands)

    Abdalla, M.M.F.

    1970-01-01

    Solanum verrucosum (2n = 24) is a self-compatible, highly fertile species. This conclusion is drawn from the results of studies on 21 various introductions of this species. In spite of self-compatibility and good male and female fertility, the species generally needs a pollinating agent to ensur

  10. Somatic hybrids of Solanum tuberosum and species of the Solanum nigrum-complex and their backcross progeny

    NARCIS (Netherlands)

    Horsman, K.

    2001-01-01

    The species of the Solanum nigrum-complex are wild relatives of the cultivated potato and potentially interesting sources of genetic variation. The traditional method of introgressing a specific trait from a related species is sexual hybridisation followed by recurrent backcrossing but often one or

  11. Quantification of vitamin D3 and its hydroxylated metabolites in waxy leaf nightshade (Solanum glaucophyllum Desf.), tomato (Solanum lycopersicum L.) and bell pepper (Capsicum annuum L.)

    DEFF Research Database (Denmark)

    Jäpelt, Rie Bak; Silvestro, Daniele; Smedsgaard, Jørn

    2013-01-01

    Changes in vitamin D3 and its metabolites were investigated following UVB- and heat-treatment in the leaves of Solanum glaucophyllum Desf., Solanum lycopersicum L. and Capsicum annuum L. The analytical method used was a sensitive and selective liquid chromatography electrospray ionisation tandem...

  12. A Cost Model for Storage and Weeding Programs.

    Science.gov (United States)

    Lawrence, Gary S.

    1981-01-01

    Presents a simple cost model to analyze trade-offs involved in considering storage and weeding as alternatives to new construction for academic libraries. References are provided, and the Palmour cost model is presented as an appendix. (RAA)

  13. Research on weed species for phytoremediation of boron polluted soil

    African Journals Online (AJOL)

    STORAGESEVER

    2009-09-15

    Sep 15, 2009 ... Full Length Research Paper. Research on weed species for phytoremediation of boron polluted soil ... There are many geothermal fields and thermal springs ..... of Geotermal Energy for Electric Power Production and Space.

  14. PRODUCTION OF BIOG S FROM COW DUNG, WEEDS ND ...

    African Journals Online (AJOL)

    USER

    2017-05-26

    May 26, 2017 ... the anaerobic fermentation of weeds and domestic waste; to determine the ratios of cow ... production; to determine the burning characteristic of the gas produced and to determine ... as newspapers, filter, paper, banana skins,.

  15. Cultural control of weeds in herbicide-free annual forages

    Science.gov (United States)

    The adoption of zero tillage systems improves soil water conservation, allowing for increased crop intensification and diversification in the semiarid northern Great Plains. Zero tillage systems rely primarily on herbicides for weed management, increasing selection pressure for herbicide resistance...

  16. Standardization of DNA extraction from invasive alien weed ...

    African Journals Online (AJOL)

    DNA isolation from the weed, Parthenium hysterophorus is complicated due to the ... version of cetyltrimethylammonium bromide (CTAB) method constituting high ... The resulted genomic DNA showed fine random amplified polymorphic DNA ...

  17. Vomiting Disorder on Rise in Weed-Friendly Colorado

    Science.gov (United States)

    ... fullstory_162895.html Vomiting Disorder on Rise in Weed-Friendly Colorado Doctors say problem may become more ... Jan. 5, 2017 (HealthDay News) -- Long-term heavy marijuana use can cause chronic vomiting and abdominal pain ...

  18. Characterization of weed flora in rubber trees plantations of Bongo ...

    African Journals Online (AJOL)

    SARAH

    2013-10-31

    Oct 31, 2013 ... of 1 and 2 years old, weeds were dominated by leguminous cover crop Pueraria phaseoloides (Roxb.) Benth. ... diminish the growth of the tree by up to 50% (Grist ... diversity of the plantation, (2) analyze the evolution.

  19. Weed control and selectivity of flumioxazin in eucalyptus

    Directory of Open Access Journals (Sweden)

    Rafael Augusto Soares Tiburcio

    2012-12-01

    Full Text Available Flumioxazin is a registered herbicide for agricultural crops what is an important fact concerning integrated management for weeds in eucalyptus plantations. This study evaluated the efficiency of weed control and the phytotoxicity in eucalyptus plants caused by the herbicide flumioxazin applied alone or in tank mixture with sulfentrazone and isoxaflutole. The aim was to extend the use of thisherbicide in eucalyptus. The herbicide was applied to eucalyptus plants using precision backpack sprayer. It was evaluated, visually,the intoxication percentage and measured height and diameter of eucalyptus trees, the control plants and dry mass of weeds. It wasconcluded that flumioxazin is selective to the eucalyptus at the 125 g.ha-1 dosage, and its efficiency in controlling weeds pre-emergencewas better when mixed in the tank with isoxaflutole and sulfentrazone.

  20. Weed Control Sprayers: Calibration and Maintenance. Special Circular 81.

    Science.gov (United States)

    Myers, Arthur L.

    This manual covers aspects of calibration and maintenance of weed control sprayers including variables affecting application rate, the pre-calibration check, calculations, band spraying, nozzle tip selection, agitation, and cleaning. (BB)