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Sample records for picloram

  1. Picloram and Aminopyralid Sorption to Soil and Clay Minerals

    Science.gov (United States)

    Aminopyralid sorption data are lacking, and these data are needed to predict off-target transport and plant available herbicide in soil solution. The objective of this research was to determine the sorption of picloram and aminopyralid to five soils and three clay minerals and determine if the pote...

  2. Picloram Movement in Soil Solution and Streamflow from a Coastal Plain Forest

    Science.gov (United States)

    Jerry L. Michael; D.G. Neary; M.J.M. Wells

    1989-01-01

    Picloram (4-amino-3,5,6-trichloropicolinic acid) was aerially applied to P longleaf pine (Pinus palustris L.) site in the upper constnl plain of Alabama to control kudzu [Purraria lobota (Willd.) Ohwi]. Pellets (10% a.i.) were spread at the rate of 56 kg ha-1 on loamy sand Typic Knnhspludult soils....

  3. Determination of Picloram in Soil and Water by Reversed-Phase Liquid Chromatography

    Science.gov (United States)

    M.J.M. Wells; J.L. Michael; D.G. Neary

    1984-01-01

    A reversed-phase liquid chromatographic method is presneted for the determination of picloram in the parts per billion (ppb) range in soil, soil solution, and stream samples. Quanitification is effected by UV absorpation at 254 nm. Derivatization is not necessary. The method permits 92% ± 7.1 recovery from water samples and 61.8% ± 11.1 recovery from soil samples....

  4. Risk of Soil Recontamination Due to Using Eleusine coracana and Panicum maximum Straw After Phytoremediation of Picloram.

    Science.gov (United States)

    Nascimento, Alex Favaro; Pires, Fábio Ribeiro; Chagas, Kristhiano; de Oliveira Procópio, Sergio; Oliveira, Marcelo Antonio; Cargnelutti Filho, Alberto; Belo, Alessandra Ferreira; Egreja Filho, Fernando Barboza

    2015-01-01

    This study aimed to evaluate the herbicidal activity of picloram on the biomass of the remediation plants Eleusine coracana and Panicum maximum after cultivation in a soil contaminated with this herbicide. These species were grown in three soils, differentiated based on texture (clayish, middle, and sandy, with 460, 250, and 40 g kg(-1) of the clay, respectively), previously contaminated with picloram (0, 80, and 160 g ha(-1)). After 90 days, the plants were harvested and an extract was produced by maceration of leaves and stems of these plants. It was applied to pots containing washed sand, comprising a bioassay in a growth chamber using soybean as a bioindicator for picloram. Soil and plant samples were analyzed by HPLC. The results showed the presence of picloram or metabolites with herbicidal activity in the shoots of E. coracana and P. maximum at phytotoxic levels with regard to soybean plants, indicating that they work only as phytoextractors and that the presence of straw on the soil surface can promote recontamination within the area. It is not recommended to cultivate species susceptible to picloram in areas where it was reported remediation by E. indica and P. maximum and still present residues of these species.

  5. Influence of 2,4-D and picloram on embryogenic competence of three cassava (manihot esculenta crantz) accessions

    International Nuclear Information System (INIS)

    Elegba, W.

    2008-06-01

    The influence of 2,4-D and picloram on embryogenic competence of three local cassava accessions namely, Nkabom, Wenchi and ADI 001 was studied. Young leaf lobes of cassava cultured on MS medium supplemented with 4 to 20 mg/L 2,4-D or picloram (initiation medium) resulted in 90 to 100% embryogenic calli formation depending on the accession. The transfer of embryogenic calli to an MS medium supplemented with 0.1 mg/L BAP produced primary embryos. The duration and number of primary embryos produced on the maturation medium depended on the auxin as well as the genotype. picloram decreased the number of days to maturation and produced comparatively more embryos at both the primary and cyclic stages than 2,4-D. However, the optimal concentration required for increased embryo production in picloram was higher (16 mg/L) than 2,4-D ( 8 mg/L). Fragmentation of matured primary somatic embryos and reculture on initiation medium led to cyclic embryo production. Cyclic embryogenesis doubled (with 2,4-D) or tripled (with picloram) the number of embryos produced at the primary stage. However, recycling of embryos through three successive cycles resulted in a slight reduction in the number of embryos produced. The presence of lower concentration of ABA (1 mg/L) in the maturation medium enhanced embryo maturation and plantlet regeneration while increased concentration of ABA (2 or 4 mg/L) decreased embryo production and plantlet regeneration indicating inhibition or dormancy effect of the growth regulator on germination of embryos. Desiccation significantly (P ≤ 0.05) improved plantlet regeneration from both 2,4-D and picloram-induced somatic embryos in all the accessions. However, comparatively high somatic embryos derived from picloram germinated into plantlets than 2,4-D.This study has shown that all three accessions, are embryogenically competent and picloram is a superior auxin to 2,4-D in somatic embryo production and successful regeneration of plantlets. This holds great

  6. Fitorremediação de solo contaminado com picloram por capim-pé-de-galinha-gigante (Eleusine coracana Phytoremediation of picloram-contaminated soil by Eleusine coracana

    Directory of Open Access Journals (Sweden)

    Sergio de Oliveira Procópio

    2008-12-01

    Full Text Available O longo efeito residual do herbicida picloram no solo aumenta o risco de lixiviação e de fitotoxicidade em culturas sucedâneas; sua presença no solo pode ser abreviada com o uso da fitorremediação. O objetivo deste trabalho foi avaliar a influência da densidade populacional de capim-pé-de-galinha-gigante (Eleusine coracana sobre a fitorremediação de solo contaminado com o herbicida picloram. O experimento foi realizado em casa de vegetação localizada no município de Rio Verde-GO, no período de setembro de 2006 a fevereiro de 2007. Os tratamentos foram compostos pela combinação entre quatro densidades populacionais da espécie vegetal Eleusine coracana (capim-pé-de-galinha-gigante (0, 7, 14 e 21 plantas por vaso, correspondendo a 0, 172, 344 e 516 plantas m-2, respectivamente e três doses do picloram (0, 80 e 160 g ha-1 - aplicadas diretamente nos vasos, simulando níveis de contaminação do solo. Após o cultivo da espécie vegetal fitorremediadora no substrato por 100 dias, efetuou-se, no próprio vaso, a semeadura da soja (Glycine max L., espécie utilizada como bioindicadora da presença do picloram. A espécie Eleusine coracana mostrou ter capacidade de remediar solos contaminados com o herbicida picloram. A partir de 172 plantas m-2, aumentos na densidade populacional da espécie fitorremediadora não proporcionaram redução de carryover do herbicida picloram sobre a cultura da soja semeada em sucessão.The long-term residual effect of the herbicide picloram poses risks of leaching and phytotoxicity to successive crops. Phytoremediation can abbreviate the long carryover effect. This research was carried out from September 2006 to February 2007, under green house conditions, in Rio Verde, Goiás, Brazil, to study the influence of Eleusine coracana population density on phytoremediation of soil contaminated with picloram. The treatments consisted of the combination of four Eleusine coracana population densities (0, 7, 14

  7. New insights on the structure of the picloram-montmorillonite surface complexes.

    Science.gov (United States)

    Marco-Brown, Jose L; Trinelli, María Alcira; Gaigneaux, Eric M; Sánchez, Rosa M Torres; Afonso, María dos Santos

    2015-04-15

    The environmental mobility and bioavailability of Picloram (PCM) are determined by the amine and carboxylate chemical groups interaction with the soils mineral phases. Clay particles, such as montmorillonite (Mt), and the pH value of the media could play an important role in adsorption processes. Thus, the study of the role of soil components other than organic matter deserves further investigation for a more accurate assessment of the risk of groundwater contamination. Samples with PCM adsorbed on Mt dispersions were prepared at pH 3-9. Subsequently, the dispersions were separated, washed, centrifuged and stored at room temperature. Picloram (PCM) herbicide interaction with surface groups of montmorillonite (Mt) was studied using XRD, DTA, FTIR and XPS techniques. The entrance of PCM into the Mt basal space, in two different arrangements, perpendicular and planar, is proposed and the final arrangement depends on PCM concentration. The interaction of PCM with Mt surface sites through the nitrogen of the pyridine ring and carboxylic group of PCM, forming bidentate and bridge inner-sphere complexes was confirmed by FTIR and XPS analysis. The acidity constant of the PCM adsorbed on the Mt surface was calculated. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. THE EFFECT OF PICLORAM AND LIGHT ON SOMATIC EMBRYOGENESIS REGENERATION OF PINEAPPLE

    Directory of Open Access Journals (Sweden)

    Ika Roostika

    2012-10-01

    Full Text Available Smooth Cayenne is the largest pineapple type cultivated in Indonesia, but its vegetative planting materials for mass propagation are limited. Somatic embryogenesis is a potential method to be applied. The aim of this study was to investigate the somatic embryogenesis regeneration under the effect of picloram and light. Callus formation was induced by picloram (21, 41 and 62 μM added with 9 μM thidiazuron. The calli were transferred onto MS or Bac medium  enriched with N-organic compounds with or without addition of 21 μM picloram under dark or light condition. The compact calli were subcultured onto MS medium supplemented with 4.65 μM kinetin, while the friable calli were  transferred onto BIG medium (modified MS + 1.1 μM benzyl adenine + 0.9 μM indole butyric acid + 0.09 μM giberelic acid or B medium (MS + 0.018 mM benzyl adenine. The results showed that the events of somatic embryogenesis were started from cell polarization, asymmetrical division, proembryo formation as  embryogenic tissues and friable embryogenic tissues, and embryo development. The best treatment for callus induction was 21 μM picloram. The addition of 21 μM picloram on N-organic enriched medium and the use of light condition  proliferated embryogenic calli. The N-organic enriched Bac medium and light condition yielded the highest number of mature somatic embryos (17 embryos perexplant in 2 months. The B medium was better than BIG medium to develop  somatic embryos from friable embryogenic tissues. The somatic embryogenesis method presented is potential for pineapple mass propagation and artificial seedproduction.Abstrak Bahasa IndonesiaSmooth Cayenne merupakan kultivar nenas yang banyak dibudidayakan di  Indonesia, namun ketersediaan benih untuk perbanyakan massal masih terbatas. Embriogenesis somatikadalah metode yang potensial untuk produksi bibit secara massal. Tujuan penelitian adalah untuk mempelajari pengaruh pikloram dan pencahayaan terhadap regenerasi

  9. Determination of picloram in natural waters employing sequential injection square wave voltammetry using the hanging mercury drop electrode.

    Science.gov (United States)

    Dos Santos, Luciana B O; Masini, Jorge C

    2007-05-15

    This paper describes the development of a sequential injection analysis method to automate the determination of picloram by square wave voltammetry exploiting the concept of monosegmented flow analysis to perform in-line sample conditioning and standard addition. To perform these tasks, an 800muL monosegment is formed, composed by 400muL of sample and 400muL of conditioning/standard solution, in medium of 0.10molL(-1) H(2)SO(4). Homogenization of the monosegment is achieved by three flow reversals. After homogenization the mixture zone is injected toward the flow cell, which is adapted to the capillary of a hanging drop mercury electrode, at a flow rate of 50muLs(-1). After a suitable delay time, the potential is scanned from -0.5 to -1.0V versus Ag/AgCl at frequency of 300Hz and pulse height of 25mV. The linear dynamic range is observed for picloram concentrations between 0.10 and 2.50mgL(-1) fitting to the linear equation I(p)=(-2.19+/-0.03)C(picloram)+(0.096+/-0.039), with R(2)=0.9996, for which the slope is given in muALmg(-1). The detection and quantification limits are 0.036 and 0.12mgL(-1), respectively. The sampling frequency is 37h(-1) when the standard addition protocol is followed, but can be increased to 41h(-1) if the protocol to obtain in-line external calibration curve is used for quantification. The method was applied for determination of picloram in spiked water samples and the accuracy was evaluated by comparison with high performance liquid chromatography using molecular absorption at 220nm for detection. No evidences of statistically significant differences between the two methods were observed.

  10. Atrazine and picloram adsorption in organic horizon forest samples under laboratory conditions Adsorção de atrazina e picloram em amostras florestais de horizonte orgânico

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    A.P. Pinho

    2007-03-01

    Full Text Available Adsorption of two herbicides, atrazine and picloram, displaying different sorption characteristics, were evaluated for O (organic horizon samples collected from SMZs (streamside management zones in Piedmont (Ultisol of Georgia, USA. Samples were randomly collected from within 5 SMZs selected for a study of surface flow in field trials. The five SMZs represented five different slope classes, 2, 5, 10, 15 and 20%. Results indicate that 0 horizons have the potential for sorbing atrazine from surface water moving through forested SMZs. Atrazine adsorption was nearly linear over a 24-hour period. Equilibrium adsorption, determined through 24-hour laboratory tests, resulted in a Freundlich coefficient of 67.5 for atrazine. For picloram, negative adsorption was observed in laboratory experiments. This seemed to be due to interference with ELISA analyses; however, this was not confirmed. The adsorption coefficient (Kd obtained for atrazine in 0 horizons was greater than it would have been expected for mineral soil (from 1 to 4. Picloram was not sorbed in 0 horizons at any significant degree. Although there is a significant potential for the direct adsorption of soluble forms of herbicides in SMZs, the actual value of this adsorption for protecting water is likely to be limited even for relatively strongly sorbed chemicals, such as atrazine, due to relatively slow uptake kinetics.Este trabalho avaliou a adsorção de dois herbicidas - atrazina e picloram - com diferentes características de sorção, em amostras florestais de horizonte orgânico (HO coletadas em matas ciliares de manejo (MCM localizadas em uma região de Piedmond (Ultisol, no estado da Geórgia, EUA. As amostras foram coletadas aleatoriamente dentro de cinco áreas de mata ciliar distintas, em classes de declividade de 2, 5, 10, 15 e 20%, as quais foram selecionadas para desenvolver experimentos de campo sobre o transporte de herbicidas por escoamento superficial. Os resultados indicam

  11. Ação de Eleusine coracana na remediação de solos contaminados com picloram Action of Eleusine coracana in the remediation of soils contaminated with picloram

    Directory of Open Access Journals (Sweden)

    L.O.C. Silva

    2012-09-01

    Full Text Available A evolução do método químico de controle das plantas daninhas tem sido fundamental para o cultivo de grandes áreas com custos de produção compatíveis com os mercados nacional e internacional. Atualmente, os herbicidas representam cerca de 45,0% de todos os agrotóxicos consumidos no Brasil. Esses compostos, em sua grande maioria, podem apresentar longa persistência no ambiente e contaminar o solo, impedindo novos cultivos, e também as águas superficiais e subterrâneas, gerando como consequência problemas ambientais. Objetivou-se com este trabalho quantificar, por meio da técnica cromatográfica, a capacidade da espécie E. coracana em reduzir a persistência do picloram em dois tipos de solo - um Latossolo Vermelho-Amarelo e um Argissolo Vermelho-Amarelo - largamente cultivados com pastagens e culturas no Brasil, contaminados com esse herbicida. Conclui-se que a espécie E. coracana é eficiente na remediação de solos contaminados por esse herbicida, evidenciando o potencial de uso dela em programas de fitorremediação de áreas contaminadas e redução do risco de impacto ambiental, e que os valores da meia-vida do picloram nos solos avaliados são distintos para uma mesma condição climática, o que pode ser ainda mais diferente em campo.The evolution of chemical weed control methods has been fundamental to cultivation of large areas where production costs are compatible with national and international markets. Currently, herbicides account for approximately 45.0% of all pesticides used in Brazil. Most of these compounds present long persistence in the environment, contaminating soil, hindering new crops as well as surface water and groundwater, thus leading to environmental problems. The objective of this work was to quantify, using the chromatographic technique, the efficacy of the species E. coracana in reducing picloram persistence in two soils, a Red Yellow Ultisol and a Red Yellow Latosol, treated with this herbicide

  12. Electrochemical degradation of the herbicide picloram using a filter-press flow reactor with a boron-doped diamond or β-PbO2 anode

    International Nuclear Information System (INIS)

    Pereira, Gabriel F.; Rocha-Filho, Romeu C.; Bocchi, Nerilso; Biaggio, Sonia R.

    2015-01-01

    Galvanostatic electrolyses are performed in a filter-press reactor to investigate the electrochemical degradation of picloram (100 mg L −1 , from a commercial herbicide formulation) using a boron-doped diamond (BDD) or β-PbO 2 anode. The effect of pH (3, 6, or 10), applied current density (j apl = 10, 30, or 50 mA cm −2 ), and absence or presence of Cl – ions (25 mM) in the supporting electrolyte (aqueous 0.10 M Na 2 SO 4 ) is investigated, while the picloram concentration, solution chemical oxygen demand (COD) and total organic carbon content (TOC), and energy consumption are monitored as a function of electrolysis time. From the obtained results, it is clear that the electrochemical degradation of picloram is possible using either of the anodes, but with different overall performances. In general, the presence of Cl – ions in the supporting electrolyte (leading to electrogenerated active chlorine) has a positive effect on the performance of both anodes, except for TOC abatement using the BDD anode; the best electrodegradation performances are attained at pH values around 6, when HClO is the predominant active-chlorine species. Faster rates of initial electrodegradation of picloram and of solution TOC abatement are obtained as j apl is increased, but, as expected, lower energy consumptions are always attained at the lowest value of j apl . The performances of the two anodes are virtually the same in the initial degradation of picloram; however, the BDD anode greatly surpasses the β-PbO 2 anode in the abatement of solution COD or TOC. This confirms the importance of the oxidation power of the anode, even when indirect oxidation by active chlorine plays a concomitant role.

  13. Influência do oeríodo de cultivo de Panicum maximum (cultivar Tanzânia na fitorremediação de solo contaminado com picloram Influence of Panicum maximum cultivation period on phytoremediation of soil contaminated with picloram

    Directory of Open Access Journals (Sweden)

    M.L. Carmo

    2008-06-01

    Full Text Available O objetivo deste trabalho foi avaliar a influência do tempo de cultivo de Panicum maximum (cultivar Tanzânia sobre a fitorremediação de solo contaminado com picloram. O experimento foi conduzido em casa de vegetação no período de setembro de 2006 a fevereiro de 2007. Os fatores foram compostos pela combinação entre quatro períodos de cultivo da espécie vegetal Panicum maximum (cultivar Tanzânia (0, 60, 80 e 100 dias e três doses do picloram (0, 80 e 160 g ha-1, totalizando 12 tratamentos. O delineamento experimental utilizado foi o inteiramente casualizado em esquema fatorial 4 x 3, com quatro repetições. Como substrato utilizaram-se amostras de solo classificado como Latossolo Vermelho eutroférrico. Após o tempo estabelecido de atuação da espécie fitorremediadora, efetuou-se a semeadura das espécies bioindicadoras da presença do picloram: tomate e soja. As espécies bioindicadoras demonstraram alta sensibilidade à presença do picloram no solo, sendo inviável o cultivo dessas culturas em áreas contaminadas com esse herbicida sem a execução de algum procedimento remediador. O cultivo prévio de Tanzânia por 60 dias garantiu crescimento inicial satisfatório das plantas de soja e tomate quando a contaminação inicial não foi maior que 80 g ha-1 de picloram. Acima desse valor, a fitorremediação ocorrida proporcionou menor crescimento das plantas de soja e tomate, sendo necessário maior tempo de descontaminação.The objective of this study was to evaluate the influence of cultivation time of Panicum maximum (cv. Tanzania on phyto-remediation of soil contaminated with picloram. The experiment was carried out under greenhouse conditions from September 2006 to February 2007, using euthroferric Red Latosol samples as substrate for plant growth. The experiment was arranged in a completely randomized design, with four replicates, with treatments in a 4 x 3 factorial scheme. The treatments comprised twelve combinations of

  14. Influência do período de cultivo do capim-pé-de-galinha-gigante (Eleusine coracana na fitorremediação de solo contaminado com picloram Influence of Eleusine coracana cultivation period on phytoremediation of soil contaminated with picloram

    Directory of Open Access Journals (Sweden)

    M.L. Carmo

    2008-01-01

    Full Text Available O objetivo deste trabalho foi avaliar a influência do período de cultivo do capim-pé-de-galinha-gigante (Eleusine coracana sobre a fitorremediação de solo contaminado com picloram. O experimento foi conduzido em casa de vegetação, no período de setembro de 2006 a fevereiro de 2007. Os tratamentos foram compostos pela combinação entre quatro períodos de cultivo da espécie vegetal Eleusine coracana (0, 60, 80 e 100 dias e três doses do picloram (0, 80 e 160 g ha-1, totalizando 12 tratamentos. O delineamento experimental utilizado foi o inteiramente casualizado em esquema fatorial 4 x 3, com quatro repetições. Como substrato para o crescimento das plantas, utilizaram-se amostras de solo classificado como Latossolo Vermelho eutroférrico. Ao término do período estabelecido de atuação da espécie fitorremediadora, efetuou-se a semeadura das espécies bioindicadoras da presença do picloram: tomate (cultivar Santa Clara e soja (cultivar Monsoy 6101. As espécies bioindicadoras demonstraram alta sensibilidade à presença do picloram no solo, sendo inviável o cultivo dessas culturas em áreas contaminadas com esse herbicida sem a execução de algum procedimento remediador. O cultivo prévio de E. coracana por 60 dias reduziu a contaminação do solo com picloram e permitiu crescimento inicial satisfatório das plantas de soja e de tomate cultivadas em solo que recebeu previamente a aplicação de até 160 g ha-1 de picloram; contudo, essas plantas bioindicadoras apresentaram ainda sintomas visíveis de intoxicação do herbicida.The objective of this study was to evaluate the influence of Eleusine coracana cultivation period on phytoremediation of soil contaminated with picloram. The experiment was carried out at a greenhouse from September 2006 to February 2007, in 12 treatments combining four Eleusine coracana cultivation periods ((0, 60, 80 and 100 days and three picloram rates (0, 80 and 160 g ha-1, arranged in a completely

  15. Lixiviação do picloram em argissolo vermelho-amarelo e latossolo vermelho-amarelo com diferentes valores de pH Picloram leaching on red-yellow latosol and red-yellow ultisol with different pH values

    Directory of Open Access Journals (Sweden)

    L. D'Antonino

    2009-01-01

    Full Text Available O objetivo deste trabalho foi avaliar o potencial de lixiviação do picloram em solos utilizados em pastagens no Brasil (Argissolo Vermelho-Amarelo e Latossolo Vermelho-Amarelo, com dois valores de pH. Para isso, amostras desses solos coletadas à profundidade de 0-20 cm (incubadas ou não com calcário por um período de 70 dias foram utilizadas como substrato para preenchimento de colunas de PVC de 10 cm de diâmetro por 50 cm de comprimento. Realizou-se um experimento em esquema de parcela subsubdividida, em delineamento inteiramente casualizado, com quatro repetições. Os tratamentos compreenderam a combinação de uma dose do herbicida picloram (160 g ha-1, três intensidades de chuva (40, 80 e 120 mm, três tipos de solo e 10 profundidades de amostragem nas colunas. As avaliações realizadas foram relativas ao desenvolvimento das plantas indicadoras nos substratos das colunas nas profundidades de 0-5, 5-10, 10-15, 15-20, 20-25, 25-30, 30-35, 35-40, 40-45 e 45-50 cm. Após o preparo das colunas, estas foram umedecidas e colocadas na posição vertical para drenagem do excesso de água. Após esse período, aplicou-se no topo delas o herbicida e, 12 horas depois, foram feitas as simulações das chuvas, especificadas de acordo com o tratamento. Elas permaneceram na posição vertical por mais 72 horas, para drenagem e lixiviação do herbicida. Após esse período, as colunas foram abertas longitudinalmente e colocadas na posição horizontal, semeando-se ao longo delas a espécie indicadora (Cucumis sativus. Conclui-se que o picloram apresentou alta taxa de lixiviação em todos os solos estudados e que sua movimentação no perfil dos solos foi influenciada pelo volume de chuva simulado, pelo pH do solo e, também, por outras características do solo, possivelmente pelo teor de matéria orgânica. O solo com baixo teor de matéria orgânica e pH mais elevado apresentou maior índice de lixiviação do picloram aplicado à camada

  16. Using accelerated life testing procedures to compare the relative sensitivity of rainbow trout and the federally listed threatened bull trout to three commonly used rangeland herbicides (picloram, 2,4-D, and clopyralid).

    Science.gov (United States)

    Fairchild, James F; Allert, Ann; Sappington, Linda S; Nelson, Karen J; Valle, Janet

    2008-03-01

    We conducted 96-h static acute toxicity studies to evaluate the relative sensitivity of juveniles of the threatened bull trout (Salvelinus confluentus) and the standard cold-water surrogate rainbow trout (Onchorhyncus mykiss) to three rangeland herbicides commonly used for controlling invasive weeds in the northwestern United States. Relative species sensitivity was compared using three procedures: standard acute toxicity testing, fractional estimates of lethal concentrations, and accelerated life testing chronic estimation procedures. The acutely lethal concentrations (ALC) resulting in 50% mortality at 96 h (96-h ALC50s) were determined using linear regression and indicated that the three herbicides were toxic in the order of picloram acid > 2,4-D acid > clopyralid acid. The 96-h ALC50 values for rainbow trout were as follows: picloram, 41 mg/L; 2.4-D, 707 mg/L; and clopyralid, 700 mg/L. The 96-h ALC50 values for bull trout were as follows: picloram, 24 mg/L; 2.4-D, 398 mg/L; and clopyralid, 802 mg/L. Fractional estimates of safe concentrations, based on 5% of the 96-h ALC50, were conservative (overestimated toxicity) of regression-derived 96-h ALC5 values by an order of magnitude. Accelerated life testing procedures were used to estimate chronic lethal concentrations (CLC) resulting in 1% mortality at 30 d (30-d CLC1) for the three herbicides: picloram (1 mg/L rainbow trout, 5 mg/L bull trout), 2,4-D (56 mg/L rainbow trout, 84 mg/L bull trout), and clopyralid (477 mg/L rainbow trout; 552 mg/L bull trout). Collectively, the results indicated that the standard surrogate rainbow trout is similar in sensitivity to bull trout. Accelerated life testing procedures provided cost-effective, statistically defensible methods for estimating safe chronic concentrations (30-d CLC1s) of herbicides from acute toxicity data because they use statistical models based on the entire mortality:concentration:time data matrix.

  17. Optimization and validation of the solid-liquid extraction technique for determination of picloram in soils by high performance liquid chromatography Otimização e validação da técnica extração sólido-líquido para a determinação do picloram em solos por cromatografia líquida de alta eficiência

    Directory of Open Access Journals (Sweden)

    E.C Assis

    2011-09-01

    Full Text Available The objective of this study was to optimize and validate the solid-liquid extraction (ESL technique for determination of picloram residues in soil samples. At the optimization stage, the optimal conditions for extraction of soil samples were determined using univariate analysis. Ratio soil/solution extraction, type and time of agitation, ionic strength and pH of extraction solution were evaluated. Based on the optimized parameters, the following method of extraction and analysis of picloram was developed: weigh 2.00 g of soil dried and sieved through a sieve mesh of 2.0 mm pore, add 20.0 mL of KCl concentration of 0.5 mol L-1, shake the bottle in the vortex for 10 seconds to form suspension and adjust to pH 7.00, with alkaline KOH 0.1 mol L-1. Homogenate the system in a shaker system for 60 minutes and then let it stand for 10 minutes. The bottles are centrifuged for 10 minutes at 3,500 rpm. After the settlement of the soil particles and cleaning of the supernatant extract, an aliquot is withdrawn and analyzed by high performance liquid chromatography. The optimized method was validated by determining the selectivity, linearity, detection and quantification limits, precision and accuracy. The ESL methodology was efficient for analysis of residues of the pesticides studied, with percentages of recovery above 90%. The limits of detection and quantification were 20.0 and 66.0 mg kg-1 soil for the PVA, and 40.0 and 132.0 mg kg-1 soil for the VLA. The coefficients of variation (CV were equal to 2.32 and 2.69 for PVA and TH soils, respectively. The methodology resulted in low organic solvent consumption and cleaner extracts, as well as no purification steps for chromatographic analysis were required. The parameters evaluated in the validation process indicated that the ESL methodology is efficient for the extraction of picloram residues in soils, with low limits of detection and quantification.O objetivo deste trabalho foi otimizar e validar a t

  18. 40 CFR 180.292 - Picloram; tolerances for residues.

    Science.gov (United States)

    2010-07-01

    ... Cattle, fat 0.2 Cattle, kidney 5.0 Cattle, liver 0.5 Cattle, meat 0.2 Cattle, meat byproducts, except kidney and liver 0.2 Egg 0.05 Goat, fat 0.2 Goat, kidney 5.0 Goat, liver 0.5 Goat, meat 0.2 Goat, meat..., kidney 5.0 Hog, liver 0.5 Hog, meat 0.2 Hog, meat byproducts, except kidney and liver 0.2 Horse, fat 0.2...

  19. Efectividad de la mezcla picloram y fluroxipir en el control de malezas perennes de pastizales tropicales

    Directory of Open Access Journals (Sweden)

    Valent\\u00EDn A. Esqueda Esquivel

    2005-01-01

    Full Text Available Se determinóla cinética de la degradación ruminal de la materia seca, laproteína cruda y el extracto etéreo en las harinas de pescado,carne y hueso y tortave. Con base en los resultados de degradación a 48 horas de incubación ruminal, se determinó enforma biológica los contenidos digeribles reales de la proteí-na y grasa digerida, haciendo más precisa la medición del total de nutrientes digeribles y los valores de energía digestibley neta de los alimentos que por el método químico. Los valores de energía neta para producción fueron de 2,02, 1,66 y2,60 Mcals/kg en la harina de pescado, harina de carne y hue-so y la tortave, respectivamente. La fracción de proteína soluble (A fue alta en la harina de pescado (75,29%, media enla harina de carne y hueso (46,83% y más baja en la harinade tortave (25,75%, con una fracción degradable (B de10,62, 27,66 y 42,06%; así como una fracción insoluble (Cde 14,09, 25,51, y 32,19%, respectivamente. La proteína de-gradada en el rumen fue de 83,23, 66,25 y 51,98%, en el mismo orden de presentación anterior. Los contenidos de proteína cruda efectivamente retenida por el animal durante elproceso de digestión total, fueron de 53,29, 51,86 y 42,05%para la harina de pescado, harina de carne y hueso y la harina de tortave.

  20. Long-term effects of weed control with picloram along a gradient of spotted knapweed invasion

    Science.gov (United States)

    Yvette K. Ortega; Dean E. Pearson

    2011-01-01

    Broadleaf herbicides are commonly used in rangelands to suppress exotic weeds and release native communities from negative impacts of invasion. However, few studies have comprehensively evaluated treatment effects on differing community components across a gradient of initial invasion levels.We conducted a 6-yr experiment within grasslands of western Montana to measure...

  1. Vitamin C and total phenols quantification in calli of native passion fruit induced by combinations of Picloram and Kinetin

    Directory of Open Access Journals (Sweden)

    Fabiane Aparecida Artioli-Coelho

    2015-08-01

    Full Text Available Brazil is one of the center of origin of passion fruit and has an important natural variability of the genus Passiflora. Several wild species of this genus are resistant to some pests and diseases and many are considered as medicinal. The aim of this research was to induce callus from in vitro Passiflora gibertii leaf explants for quantification of vitamin C and total phenols. Once the appropriate auxin/cytokine balance promotes callus formation and may optimize the production of secondary compounds and vitamins, calli were induced using a half-strength MS medium with a combination of the auxin Picloran (PIC and the cytokine Kinetin (KIN. The vitamin C and total phenols were quantified by colorimetric methods from calli after different culture periods. The calli induction was strongly dependent of the combination PIC/KIN. It was observed high vitamin C content (94.8mg 100g-1 during the calli induction period in MS+4.14µM PIC+ 0.207µM KIN. Higher PIC/KIN concentrations promoted an increase in the vitamin C content after three subcultures. The higher PIC (8.28µM/KIN (0.828µM concentration was the higher was the total phenols production (66mg tannic acid 100g-1 of fresh callus during the calli induction period.

  2. Recovery of Picloram and 2,4-Dichlorophenoxyacetic Acid from Aqueous Samples by Reversed-Phase Solid-Phase Extraction

    Science.gov (United States)

    Martha J.M. Wells; Jerry L. Michael

    1987-01-01

    Extensive preparation of samples before chromatographic analysis is usually the most time-consuming process in the determination of many organic compounds in environmental matrices. In the past, removal of some organic from aqueous solution was commonly done by liquid/liquid extraction. However, the introduction of stable, covalently bonded reversed-phase sorbents now...

  3. Grassland response to herbicides and seeding of native grasses 6 years posttreatment

    Science.gov (United States)

    Bryan A. Endress; Catherine G. Parks; Bridgett J. Naylor; Steven R. Radosevich; Mark. Porter

    2012-01-01

    Herbicides are the primary method used to control exotic, invasive plants. This study evaluated restoration efforts applied to grasslands dominated by an invasive plant, sulfur cinquefoil, 6 yr after treatments. Of the five herbicides we evaluated, picloram continued to provide the best control of sulfur cinquefoil over 6 yr. We found the timing of picloram...

  4. Degradação do pesticida Padron® por processos fotoquímicos utilizando luz artificial e solar Degradation of Padron® by photochemical processes using artificial and sunlight radiation

    Directory of Open Access Journals (Sweden)

    Silvio César Godinho Teixeira

    2007-01-01

    Full Text Available Destruction of Padron® (dye and picloram was evaluated using a photoreactor and a solar reactor. Photolysis was observed using only a germicide lamp (GL. Black light (BL and H2O2 (172 mmol L-1 promoted a conversion of 49% and 6% of dye and picloram, respectively. Photocatalytic processes were more efficient using TiO2/GL (96%-dye; 60%-picloram than TiO2/BL (44%-dye; 40%-picloram. Photolysis using sunlight was not observed during PadronÒ recirculation in the reactor constructed with four borosilicate tubes. Meanwhile, adding H2O2 resulted in 12% conversion of dissolved organic compounds. Finally, the most efficient mineralization (60% was obtained using the Fenton reaction ( H2O2-176 mmol L-1; FeSO4x6H2O-90 mmol L-1 and sunlight.

  5. Controle de Acacia farnesiana e de Mimosa pteridofita em pastagem Control of Acacia farnesiana and of Mimosa pteridofita in pastures

    Directory of Open Access Journals (Sweden)

    Ricardo Carmona

    2001-10-01

    Full Text Available Conduziu-se um experimento com o objetivo de estudar a eficácia agronômica e econômica de herbicidas para o controle de duas sérias plantas daninhas de pastagens: Acacia farnesiana e Mimosa pteridofita. Os produtos utilizados, por meio de pincelamento no toco, foram o óleo diesel, óleo lubrificante usado de trator, solução aquosa de 2,4-D + picloram e solução oleosa de 2,4-D + picloram. À exceção do óleo lubrificante, os herbicidas foram testados em dois tamanhos de planta daninha e duas alturas de corte. Avaliaram-se a porcentagem de controle e o vigor de brotação das plantas não-controladas. Concluiu-se que o corte das plantas só é eficiente no controle das duas espécies, quando realizado no nível do solo e seguido da aplicação de herbicida específico, como o 2,4-D + picloram. O óleo diesel também controla totalmente ambas as espécies, e com menores custos que o 2,4-D + picloram, porém apenas quando aplicado nas plantas mais jovens. Há incompatibilidade entre o óleo diesel e o 2,4-D + picloram no controle das duas espécies. O óleo lubrificante usado não apresenta nenhum efeito herbicida em plantas adultas destas espécies.An experiment was carried out to study the efficacy of herbicide treatments in controlling two serious pasture weeds: Acacia farnesiana and Mimosa pteridofita. The following herbicides were applied to the stump, after cutting: diesel oil, used engine lubricant oil, 2,4-D + picloram diluted in water or diesel oil and a control treatment without herbicide. All herbicide treatments were tested on two sizes of the plants and two heights of cutting, except the lubricant oil. The shrub control and sprouting vigor were evaluated in all treatments. The results showed that cutting of plants is effective only when it is carried out at the soil surface level and followed by a specific herbicide treatment, such as 2,4-D + picloram. Diesel oil controlled 100% of the younger plants of both species, at lower

  6. Callus induction and regeneration efficiency of spring barley cultivars registered in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Šerhantová, V.; Ehrenbergerová, J.; Ohnoutková, Ludmila

    2004-01-01

    Roč. 50, č. 10 (2004), s. 456-462 ISSN 1214-1178 R&D Projects: GA MŠk OK 354 Institutional research plan: CEZ:AV0Z5038910 Keywords : immature zygotic embryos * auxin * 2,4-D-picloram Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.170, year: 2004

  7. Effects of growth regulator herbicide on downy brome (Bromus tectorum) seed production

    Science.gov (United States)

    Previous research showed growth regulator herbicides, such as picloram and aminopyralid, have a sterilizing effect on Japanese brome (Bromus japonicus Thunb.) that can reduce this invasive annual grass’s seed production nearly 100%. This suggests growth regulators might be used to control invasive ...

  8. IN VITRO CULTURE OF HOLOPARASITE Rafflesia arnoldii R. Brown

    Directory of Open Access Journals (Sweden)

    Lazarus Agus Sukamto

    2010-07-01

    Full Text Available Potongan kuncup bunga digunakan sebagai eksplan yang ditumbuhkan pada media dasar Murashige and Skoog (MS dengan tambahan 0; 0.1; 0.5; 1 and 5 mg/I 2,4-D atau Picloram dan 2 g/I Phytagel. Eksplan tumbuh menjadi kalus pada media yang ditambahkan 0,1 dan 1 mg/I 2,4-D atau 0,5 dan 1 mg/I Picloram. Kultur kalus tersebut dipelihara pada media MS + 1 mg/I 2,4-D. Kemudian kalus ditumbuhkan pada medium dengan penambahan 1, 3, 5 dan 10 mg/I 2,4-D atau Picloram. Setelah dua bulan 66,67-100% kultur membentuk kalus. Semua kalus berstruktur kompak. Beberapa kalus yang diperlakuan dengan 5-10 mg/I 2,4-D menumbuhkan benang-benang putih pada permukaannya. Perlakuan Picloram menghasilkan kalus yang lebih banyak, tetapi 2,4-D menghasilkan kualitas kalus yang lebih baik. Kalus R. arnoldii tidak membentuk somatik embrio dengan penambahan 0,1 mg/I Zeatin dalam media kultur. Ini adalah laporan yang pertama kali tentang pembentukan kalus dari kultur R. arnoldii secara in vitro.

  9. Non-target effects of broadleaf herbicide on a native perennial forb: a demographic framework for assessing and minimizing impacts

    Science.gov (United States)

    Elizabeth E. Crone; Marilyn Marler; Dean E. Pearson

    2009-01-01

    Invasive species are one of the leading threats to biodiversity worldwide. Therefore, chemical herbicides are increasingly used to control invasive plants in natural and semi-natural areas. Little is known about the non-target impacts of these chemicals on native species. We conducted an experiment to test the demographic effects of the herbicide picloram on a native...

  10. Production of the first transgenic cassava in Africa via direct shoot ...

    African Journals Online (AJOL)

    Administrator

    2006-10-02

    Oct 2, 2006 ... organogenesis systems for recovering transgenic cassava plants is described. The contributions of ... acetic acid), SSA (sub-Saharan Africa), picloram (3, 5, 6- ..... ed between Agrobacterium strains. ..... the fundamental requirements for the co-cultivated .... FAOSTAT Statistical Database: Agriculture Data.

  11. Suitability of hardwood treated with phenoxy and pyridine herbicides for firewood use

    Science.gov (United States)

    P.B. Bush; D.G. Neary; Charles K. McMahon; J.W. Taylor

    1987-01-01

    Abstract. Potential exposure to pesticide residues resulting from burning wood treated with phenoxyand pyridine herbicides was assessed. Wood samples from trees treated with 2,4-D [2,4-dichlo-rophenoxy acetic acid], dicamba [3,6-dichloro-o-anisic acid], dichlorprop [2-(2,4-dichlorphenoxy) propionic acid], picloram [4-amino-3,5,dtrichloropico-linic...

  12. The application of various chemicals to cuts made in the stem bases ...

    African Journals Online (AJOL)

    T. sericea bome was gevoelig vir boomonkruiddoder dwarsdeur die jaar. Die reaksie van alleenstaande bome op behandeling met boomonkruiddoder is verwant aan boomgrootte. Keywords: arboricides, bush control, cacodylic acid, glyphosphate, mecoprop, MCPA, picloram, stem injection, Tandex, 2,4-D, 2,4,5-T

  13. Biomass, Leaf Area, and Resource Availability of Kudzu Dominated Plant Communities Following Herbicide Treatment

    Energy Technology Data Exchange (ETDEWEB)

    L.T. Rader

    2001-10-01

    Kudzu is an exotic vine that threatens the forests of the southern U.S. Five herbicides were tested with regard to their efficacy in controlling kudzu, community recover was monitored, and interactions with planted pines were studied. The sites selected were old farm sites dominated by kudzu.These were burned following herbicide treatment. The herbicides included triclopyr, clopyralid, metsulfuron, tebuthiuron, and picloram plus 2,4-D. Pine seedlings were planted the following year. Regression equations were developed for predicting biomass and leaf area. Four distinct plant communities resulted from the treatments. The untreated check continued to be kudzu dominated. Blackberry dominated the clopyradid treatment. Metsulfron, trychlopyr and picloram treated sites resulted in herbaceous dominated communities. The tebuthiuron treatment maintained all vegetation low.

  14. Callus induction and flavonoid production on the immature seed of Stelechocarpus burahol

    Science.gov (United States)

    Habibah, N. A.; Moeljopawiro, S.; Dewi, K.; Indrianto, A.

    2018-03-01

    Stelechocarpus burahol [(Bl.) Hook. f. & Th.] is one of the medicinal plants. In vitro callus induction studies on S. burahol were carried out to determine phytohormone requirement for optimum callus induction. Immature seed explants were cultured on MS medium by adding different kinds and different concentrations of plant growth regulators (picloram and 2,4-D) under light and dark conditions. The results showed that callus formation was initiated on the 18,50th to the 55th days. The best condition for optimum callus induction was found on MS medium, which was supplemented with 7.5 mg/L picloram and was maintained in the dark condition. The callus induction varied from 60% to 100%. The callus that produced the highest flavonoid was grown on the medium with the addition of 10 mg/L of 2,4-D. In conclusion, the results represented a suitable medium for S.burahol callus induction.

  15. Herbicidas e danos físicos em tocos de teca para controle de brotos após o desbaste Herbicides and physical damages in teak stumps to control of sprouts after thinning

    Directory of Open Access Journals (Sweden)

    Sidney Fernando Caldeira

    2012-10-01

    Full Text Available Tocos de árvores desbastadas de Tectona grandis apresentam rebrota intensa que compete com as árvores remanescentes. O objetivo deste trabalho foi avaliar a eficácia da aplicação isolada ou combinada de diferentes concentrações dos herbicidas picloram e triclopyr, associados ou não à aplicação de danos físicos, no controle dessas brotações. Em um povoamento com quatro anos de idade, os tocos foram tratados imediatamente após o desbaste. Em outro povoamento com seis anos, foram tratadas as brotações presentes nos tocos desbastados no ano anterior. Foi registrada a porcentagem de tocos mortos, o número de brotações por toco e as respectivas alturas. No primeiro ensaio, a aplicação combinada de picloram a 0,48% com triclopyr a 0,96%, associada a 20 rachas com machado matou todos os tocos. No segundo ensaio, a maior eficácia, 21,7%, foi registrada com roçada prévia das brotações e a aplicação de picloram a 0,96%. Após o desbaste, a aplicação isolada de picloram ou combinada com triclopyr associada ou não aos danos físicos é eficiente para controlar os brotos de teca. A aplicação nas rebrotas de tocos desbastados no ano anterior apresenta alguma eficiência, mas com menor percentual de tocos mortos em relação à aplicação após o desbaste.The stumps of thinning trees of Tectona grandis L.f. present intense sprouts that compete with the remaining trees. The efficacy of the control of sprouts with the herbicides picloram and triclopyr, associated or no it applications of physical damages, were evaluated. Immediately after thinning, in plantation with four years old, the stumps were treated, and in other plantation, with age of six, the sprouts of stumps thinned in the previous year, were treated. The percentage of died stumps, the number of sprouts by stump and the respective heights were registered. In the first trial, the combined application of picloram at 0.48% with triclopyr at 0.96%, associated a 20 cracks

  16. Low-impact chemical weed control techniques in UNESCO World Heritage Sites of Cuba.

    Science.gov (United States)

    Hernandez-Enriquez, O; Alvarez, R; Morelli, F; Bastida, F; Camacho, D; Menendez, J

    2012-01-01

    Dichrostachys cinerea is a thorny, acacia-like, fast-growing woody bush which invades fields, wasteland, road sides and other disturbed areas. This gregarious species has become a very aggressive invasive weed in Cuba, where no native predators or pathogens are found. It often encroaches in fallows, overgrazed areas and mismanaged veld. D. cinerea is a very difficult weed to eliminate because of its active suckering, and is liable to produce dense thickets which are quite impenetrable on account of the density and abundance of its long, stiff, sharp thorns. In the Valle de los Ingenios area (Cuba Central), the tree is unchecked and forms veritable forests in areas on which cane growing has been discontinued. Physical management by cutting and burning the plants is not a very efficient control method, since the seeds survive in the soil, and they grow very fast. Therefore, chemical methods via the use of herbicides are often necessary to eradicate this weed. A preliminary study using glyphosate and auxin-like herbicides (2,4-D + picloram, MCPA, and MCPA + 2,4-D) plus adjuvants has been carried out in order to elucidate the best mixtures rendering maximum weed control with minimum herbicide rate and environmental stress. None of the herbicides used except glyphosate and 2,4-D + picloram showed acceptable mortality rates (75-80%) at the recommended doses tested. In the failed herbicide treatments, only the use of double herbicide rates succeeded in controlling marabou. The herbicide mixture of 2,4-D + picloram formulated with either a non-ionic surfactant or a mixture of fatty acid esters was the best option to control D. cinerea in terms of maximum effectiveness and minimum environmental stress, as the reduction in active ingredients applied to the environment was x3 in these two adjuvant-amended formulations compared to 2,4-D + picloram alone.

  17. Persistence of auxinic herbicides applied on pasture and toxicity for succeeding crops

    Directory of Open Access Journals (Sweden)

    ARNON H.C. ANÉSIO

    2018-04-01

    Full Text Available ABSTRACT The aim of this work was to determine the persistence of auxinic herbicides applied on tropical pasture and toxicity for succeeding crops. The herbicides were applied in an area of dystrophic red‒yellow latosol with pasture infested of weeds. At 40, 80, and 280 days after application of herbicide, the soil samples were collected at depths of 0 to 20 cm. Soil with residues of 2,4-D, 2,4-D + picloram, triclopyr, and a soil without herbicide application were analyzed with six replicates. Seven crops were cultivated in these soils: cucumber (Cucumis sativus L., velvet bean [Mucuna pruriens (L. DC.], pigeon pea [Cajanus cajan (L. Millsp.], alfalfa (Medicago sativa L., lablab bean [Lablab purpureus (L. Sweet], corn (Zea mays L., and sorghum [Sorghum bicolor (L. Moench]. The plants of cucumber, pigeon pea, and alfalfa were the most susceptible to the auxinic herbicide residues. However, the lablab bean was the only one among the dicot evaluated that showed tolerance to the 2,4-D + picloram residual when cultivated in soils at 280 days after application of herbicide. Corn and sorghum showed lower chlorophyll content in soils with 2,4-D + picloram residual up to 80 days after application of herbicide.

  18. MÉTODOS DE CONTROLE DE Prosopis juliflora (Sw. DC. (FABACEAE EM ÁREAS INVADIDAS NO SEMIÁRIDO DO BRASIL

    Directory of Open Access Journals (Sweden)

    Gerlândio Suassuna Gonçalves

    2015-01-01

    Full Text Available ABSTRACT The objective of this study was to evaluate the efficiency of different methods to control Prosopis juliflora , invasive alien species in the semiarid region of northeastern Brazil. The experimental design was completely randomized in triple factorial scheme 2x2x8 (two populations of the species, two growth stages - regenerating and adult individuals and eight control treatments, with 10 repetitions. The treatments were: control, girdling of the stem, girdling and brushing of used lubricating oil; girdling and application of 2,4-D + picloram, clear cutting, clear cutting followed by burning of the stump; clear cutting and brushing of used lubricating oil; and clear cutting and application of 2,4-D + picloram. In total 320 individuals were monitored, among these, 160 regenerates and 160 adults individuals. The variables evaluated were: percentage of control, number of shoots, diameter and length of shoots. According to the results among the treatments, those who were more effective in controlling Prosopis juliflora were clear cutting followed by burning of the stump and application of 2,4-D + picloram in cut and girdled plants. The brushing lubricating oil on the basis of girdled plants also showed a promising strategy to control invasive.

  19. Controle de Commelina benghalensis, C. erecta e Tripogandra diuretica na cultura do café Interference of Dayflower Species in Coffee Culture

    Directory of Open Access Journals (Sweden)

    A.R. Oliveira

    2009-01-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito de diferentes herbicidas/misturas no controle de três espécies de trapoeraba (Commelina benghalensis, C. erecta e Tripogandra diuretica e a tolerância de plantas jovens de café aos herbicidas. O delineamento experimental foi inteiramente casualizado, com quatro repetições. Os tratamentos foram constituídos por dez diferentes herbicidas/misturas e uma testemunha, associados a três espécies de trapoeraba. As avaliações foram realizadas aos 21 e 50 dias após a aplicação (DAP dos herbicidas, por meio de análise visual, seguindo-se escala de nível de controle. Avaliou-se a tolerância das mudas de café aos herbicidas (escala de avaliação visual da fitotoxicidade e as características de crescimento (diâmetro, número de folhas e estatura das mudas de café. A espécie C. benghalensis foi melhor controlada quando se utilizaram os herbicidas: diuron, 2,4-D + picloram, atrazine + metolachlor, metribuzin, glyphosate WG e acetochlor. A espécie C. erecta foi controlada pelos herbicidas diuron, 2,4-D + picloram, atrazine + metolachlor, glyphosate CS e acetochlor. Os herbicidas diuron, 2,4-D + picloram, atrazine + metolachlor, metribuzin, glyphosate WG e paraquat + diuron foram os que melhor controlaram T. diuretica. Metribuzin, diuron e acetochlor mostraram-se mais fitotóxicos para a cultura do café. O diuron reduziu a massa da matéria seca e o número de folhas do cafeeiro. O diâmetro do caule e a estatura foram afetados pelos herbicidas metribuzin e 2,4-D. O metribuzin foi o herbicida que maior prejuízo causou às características de crescimento da planta de café.This work aimed to evaluate the effect of different herbicides/mixtures on the control of three dayflower species (Commelina benghalensis, C. erecta. and Tripogandra diuretica and the tolerance of young coffee plants to the herbicides. The trial was arranged in a completely randomized design, constituted by ten different

  20. Pesticide sorption and leaching potential on three Hawaiian soils.

    Science.gov (United States)

    Hall, Kathleen E; Ray, Chittaranjan; Ki, Seo Jin; Spokas, Kurt A; Koskinen, William C

    2015-08-15

    On the Hawaiian Islands, groundwater is the principal source of potable water and contamination of this key resource by pesticides is of great concern. To evaluate the leaching potential of four weak acid herbicides [aminocyclopyrachlor, picloram, metsulfuron-methyl, biologically active diketonitrile degradate of isoxaflutole (DKN)] and two neutral non-ionizable herbicides [oxyfluorfen, alachlor], their sorption coefficients were determined on three prevalent soils from the island of Oahu. Metsulfuron-methyl, aminocylcopyrachlor, picloram, and DKN were relatively low sorbing herbicides (K(oc) = 3-53 mL g(-1)), alachlor was intermediate (K(oc) = 120-150 mL g(-1)), and oxyfluorfen sorbed very strongly to the three soils (K(oc) > 12,000 mL g(-1)). Following determination of K(oc) values, the groundwater ubiquity score (GUS) indices for these compounds were calculated to predicted their behavior with the Comprehensive Leaching Risk Assessment System (CLEARS; Tier-1 methodology for Hawaii). Metsulfuron-methyl, aminocyclopyrachlor, picloram, and DKN would be categorized as likely leachers in all three Hawaiian soils, indicating a high risk of groundwater contamination across the island of Oahu. In contrast, oxyfluorfen, regardless of the degradation rate, would possess a low and acceptable leaching risk due to its high sorption on all three soils. The leaching potential of alachlor was more difficult to classify, with a GUS value between 1.8 and 2.8. In addition, four different biochar amendments to these soils did not significantly alter their sorption capacities for aminocyclopyrachlor, indicating a relatively low impact of black carbon additions from geologic volcanic inputs of black carbon. Due to the fact that pesticide environmental risks are chiefly dependent on local soil characteristics, this work has demonstrated that once soil specific sorption parameters are known one can assess the potential pesticide leaching risks. Published by Elsevier Ltd.

  1. Induction and characterization of oil palm (Elaeis guineensis Jacq. pro-embryogenic masses

    Directory of Open Access Journals (Sweden)

    MARLUCIA S. PADUA

    2013-11-01

    Full Text Available ABSTRACT Oil palm is one of the most economically valuable oil seed plants, but the expansion of plantations has been limited by availability of seedlings, as the conventional propagation is through seeds, which have low germination rates. One possible solution for the large-scale production is the use of somatic embryogenesis. The aim of this study was evaluate the effects auxins 2,4-D and picloram on the induction of pro-embryogenic masses in E.guineenesis hybrid leaf explants and characterize, regarding embryogenic characteristics, with cytochemical and ultrastructural analisys. Specifically, in vitro plantlets leaves fragments were inoculated in Y3 culture medium supplemented by 2.4-D or picloram at different concentrations (0.0, 1.0, 3.0, 6.0 and 9.0 mg l–1. After 90 days the presence/ absence of cell masses were evaluated. Both growth regulators efficiently induced cellular masses regardless of the concentrations applied. As the cell masses were not homogeneously formed, they were classified according to color and shape into four types: TYPE 1 - elongated and translucent, TYPE 2 – uneven and translucent, TYPE 3 - globular and beige TYPE 4 – globular and white. Based on the anatomical and ultrastructural features, TYPE 2, 3 and 4 cell masses were considered to have the highest embryogenic potential and therefore may be most suited to large-scale vegetative propagation of oil palm.

  2. Effect of medium composition and explant size on embryogenic calli formation of cassava (Manihot esculenta Crantz local genotypes

    Directory of Open Access Journals (Sweden)

    ENNY SUDARMONOWATI

    2006-07-01

    Full Text Available Cassava (Manihot esculenta Crantz is an important tropical crop species used for human consumption, feed and raw material for various industries. Genetic transformation through embryogenic tissues is known as an effective method for cassava genetic improvements. Objective of this study was to obtain a suitable medium and length of explants to induce embryogenic callus on friable embryogenic callus (FEC as a target for genetic transformation. Immature leaf lobes (1-3 mm, 3-5 mm and larger than 5 mm in length of local genotypes of cassava (Adira 4. Menti, Iding, Gebang, Rawi and Timtim-29 cultured in vitro were used as explants. The explants were incubated for 2 and 4 weeks on MS (Murashige-Skoog or GD (Greshooff & Doy semi solid medium containing 10 mg/L picloram, 6 mg/L NAA supplemented with 4% sucrose and 4 µM CuSO4. Results showed that the highest percentage (100% of embryogenic calli formation for 4 weeks obtained by culturing Iding of 3-5 mm length on GD semi solid medium, whereas the lowest (33% one obtained by incubation 5 mm leaf lobe of Timtim-29 on the same medium. The most suitable medium for callus induction was GD, whereas the optimum length of explants was 5 mm or larger. Further study needs to be done to obtain friable embryogenic calli (FEC by employing different concentration of picloram and varying other critical factors.

  3. Callus formation of american Persea Mill. cultivar Catalina starting from segments of leaves of in vitro plants

    Directory of Open Access Journals (Sweden)

    Marisol Freire Seijo

    2004-04-01

    Full Text Available The importance of establishing protocols for the regeneration of fruit-trees through out the organogenesis and the somatic embryogenesis is based on the possibility to use them in the propagation of the species or in programs of genetic improvement. Specifically the Catalina cultivar is very coveted in Cuba, however it has not been introduced in vitro. The present work had the objective of forming callus starting from leaves of in vitro plants from avocado tree of the Catalina cultivar. The phase of multiplication of the in vitro plants was carried out in temporary immersion systems in order to favour the expansion of the leaves. Erlenmeyers 1.0l were used In the TIS and immersions every four and eight hours with a minute of duration were carried out. The effect of the Picloram, the 6 BAP and the 2,4-D on leaves of in vitro plants for the formation of callus was studied. The plants with more quality were obtained when immersions every 8 hours were carried out. It was also possible to form callus using sections of leaves of in vitro plants as explants in a culture medium with 0.1 Picloram mgl-1. Key words: in vitro plant leaves, temporary immersion system

  4. Morpho-anatomical characterization of embryogenic calluses from immature zygotic embryo of peach palm during somatic embryogenesis =

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    Simone de Alencar Maciel

    2010-04-01

    Full Text Available The objective of this study was to morpho-anatomically characterizenodular embryogenic calluses from zygotic embryos of peach palm during the induction of somatic embryogenesis. Immature zygotic embryos were pre-treated in MS medium added to Picloram and 2,4-D (25 μM and BAP (0, 5, 10 μM. After three months, primary calluses were transferred to MS induction medium added to Picloram and 2,4-D (450 μM. After six months, the embryogenic calluses were then histologically analyzed and cultivated in the maturation medium. The competent tissues of the zygotic embryos differentiated embryogenic calluses under action of both Picloram and 2,4-D auxins (450 μM, where the presence of multi-granular structures were observed. Histological observations showed that in the nodular embryogenic calluses, the outlying parenchymal cells exhibit cellular characteristics of high mitotic activity. Differentiation of tracheal elements exists in embryogenic calluses connecting the callus to the explant. The evaluated cytokinin/auxin interaction influences the development of embryogenic calluses and globular structures.O objetivo deste trabalho foi caracterizar morfoanatomicamente calos nodulares embriogênicos originados de embriões zigóticos de pupunheira durante a indução da embriogênese somática. Embriões zigóticos imaturos de pupunha foram inicialmente pré-tratados em meio de cultura MS, solidificado com 2,5 g L-1 de phytagel® e suplementado com Picloram e 2,4-D na concentração de 25 μM e BAP (0, 5, 10 μM. Após três meses, os calos primários foram transferidos para meio de indução, com Picloram e 2,4-D (450 μM. Após seis meses, os calosnodulares embriogênicos formados foram então analisados histologicamente e repicados para o meio de maturação para a progressão das estruturas multigranulares embriogênicas. Verificou-seque os tecidos competentes dos embriões zigóticos imaturos diferenciaram nódulos embriogênicos pela ação de ambas

  5. Eficácia de herbicidas no controle de amarelinho (Tecoma stans em pastagem Herbicides efficiency on trumpetflower (Tecoma stans

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    Telma Passini

    1997-01-01

    Full Text Available Amarelinho (Tecoma stans é um arbusto exótico que foi observado como espécie invasora de past os degradados do Estado do Paraná-Brasil. A população dessa espécie forma um dossel denso sob o qual as forrageiras não se desenvolvem. Visando encontrar uma alternativa de controle químico, testou-se a eficiência da formulação comercial de 2,4-D + picloram e tebuthiuron, em experimentos separados. Com a formulação comercial de 2, 4-D + picloram preparou-se uma solução em água e em óleo lubrificante usado, nas concentrações de 4% e 10%. As soluções a 4% foram pinceladas no toco, imediatamente após o tronco ter sido cortado rente ao solo e, aquelas a 10%, pinceladas em tronco ferido com facão na base do tronco, sem eliminar a parte aérea. Tebuthiuron, em formulação granulada, foi aplicado nas doses de 2, 4, 6, 8, 10 e 20 g/ planta, sem eliminar a parte aérea. A formulação de 2,4 -D + picloram não matou as plantas de amarelinho que, aos cinco meses após tratadas, apresentavam brotações com 0, 74 a 1, 21 m de altura. A menor do sede tebuthiuron foi suficiente para matar as plantas num período de nove meses após a aplicação do herbicida.Trumpet flower (Tecoma stans is na exotic woody shrub observed as an invader of degraded pastures in the State of Parana - Brazil. The canopy of trumpetflower is so dense that no forage plants growunderneath. The chemical control of this weed was tested in two experiments, using the commercial formulation of 2,4-D + picloram and tebuthiuron. The former was prepared as a solution into water or lubricative used oil, at the concentrations of 4 and 10%. The solutions at 4% were used for painting the stumps immediatly after trunks had being cut off, close to the ground level. The solutions at 10% were used for painting the basal portion of the trunks, immediatly after damaging it with a machete close to the ground level. Tebuthiuron was used granulated at doses of 2, 4, 6, 8, 10 e 20 g

  6. Streamside management zone (SMZ efficiency in herbicide retention from simulated surface flow Eficiência de zonas ripárias (SMZ na retenção de herbicidas presentes em escoamento superficial simulado

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    A.T. Matos

    2008-03-01

    Full Text Available Plot-scale overland flow experiments were conducted to evaluate the efficiency of streamside management zones (SMZs in retaining herbicides in runoff generated from silvicultural activities. Herbicide retention was evaluated for five different slopes (2, 5, 10, 15, and 20%, two cover conditions (undisturbed O horizon and raked surface, and two periods under contrasting soil moisture conditions (summer dry and winter wet season and correlated to O horizon and site conditions. Picloram (highly soluble in water and atrazine (moderately sorbed into soil particles at concentrations in the range of 55 and 35 µg L-1 and kaolin clay (approximately 5 g L-1 were mixed with 13.000 liters of water and dispersed over the top of 5 x 10 m forested plots. Surface flow was collected 2, 4, 6, and 10 m below the disperser to evaluate the changes in concentration as it moved through the O horizon and surface soil horizon-mixing zone. Results showed that, on average, a 10 m long forested SMZ removed around 25% of the initial concentration of atrazine and was generally ineffective in reducing the more soluble picloram. Retention of picloram was only 6% of the applied quantity. Percentages of mass reduction by infiltration were 36% for atrazine and 20% for picloram. Stronger relationships existed between O horizon depth and atrazine retention than in any other measured variable, suggesting that better solid-solution contact associated with flow through deeper O horizons is more important than either velocity or soil moisture as a determinant of sorption.Experimento de escoamento superficial, em escala piloto, foi conduzido para se avaliar a eficiência de zonas ripárias (SMZs na retenção de herbicidas presentes no escoamento superficial gerado em atividades silviculturais. A retenção do herbicida foi avaliada em terrenos com cinco diferentes declividades (2, 5, 10, 15 e 20%, duas condições de cobertura do solo (com e sem o horizonte O e dois períodos de

  7. Modelagem da retenção de herbicidas em zonas ripárias Modeling of herbicide retention in riparian zones

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    Alexandra P. de Pinho

    2006-12-01

    Full Text Available O presente trabalho teve como objetivo investigar a retenção de atrazina e picloram, transportados via escoamento superficial, em zona ripária. Para isto, simulou-se um escoamento superficial, contendo uma mistura de caulinita, atrazina e picloram, dentro de zonas ripárias estabelecidas ao longo de plantações de pinheiros do Nordeste do Estado da Geórgia, EUA. Cinco parcelas foram instaladas dentro de zonas ripárias, apresentando declividades diferentes (2, 5, 10, 15 e 20%. Os efeitos da umidade do solo e da presença do horizonte O na retenção dos dois herbicidas foram avaliados. Um modelo exponencial, comumente utilizado na estimativa de redução da DBO e de nutrientes em tratamento por escoamento superficial, foi empregado na estimativa de redução de herbicidas e caulinita em zonas ripárias. O modelo possibilitou estimar com razoável precisão, a remoção de caulinita e atrazina da mistura em escoamento ao longo de zonas ripárias de 10 m de comprimento. Em geral, a declividade foi o parâmetro que apresentou melhor correlação com a retenção dos contaminantes presentes na mistura em escoamento na zona ripária. O horizonte O, mais espesso nas maiores declividades, favoreceu tanto a sedimentação da caulinita como a adsorção da atrazina.This work aimed to investigate the retention of atrazine and picloram, carried by surface flow, in riparian zones. The surface flow, containing a mixture of both herbicides and kaolin, was then simulated within riparian zones established in pine plantations in north-eastern Georgia, USA. Five plots were established within riparian zones, each with a different slope (2, 5, 10, 15 and 20%. The influence of the initial moisture and of the O horizon condition in herbicide retention was analyzed. An exponential model, commonly used for the estimate of biochemical demand of oxygen (BOD and nutrients attenuation in overland flow treatment, was used to estimate the attenuation of kaolin and

  8. El viroide de la mancha del sol (ASBVd es persistente en cultivos nucelares de aguacate (Persea americana Mill.

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    Isidro E Suárez

    2005-07-01

    Full Text Available Con el objetivo de determinar la posibilidad de obtener tejidos sanos a partir de plantas infectadas con ASBVd como una estrategia para recuperar clones de alto valor agronómico, cultivos embriogénicos de aguacate fueron inducidos a partir del nucelo de tres cultivares de aguacate infectados con el viroide de la mancha del sol (ASBVd en un medio de cultivo con las sales mayores B5, suplementado con las sales menores de Murashige y Skoog (MS y 0.41 uM de picloram, y (en mg/L-1 tiamina HCl (0.4, mio-inositol (100, sucrosa (30,000 y TC agar (8,000. Los cultivos embriogénicos inducidos fueron mantenidos en medio semisólido MS suplementado con 0.41 uM de picloram y (en mg/L-1 tiamina HCl (0.4, mio-inositol (100, sucrosa (45,000 y TC agar (8,000 y en medio líquido MS modificado con 15 mM NH4NO3 y 30 mM KNO3, sales menores de MS, picloram 0.41 uM y (en mg/L-1 tiamina HCl (0.4, mio-inositol (100 y sucrosa (45,000. La indexación usando RT-PCR un año después de inducidos los tejidos detectó bandas amplificadas en los electroferogramas y la clonación comprobó la presencia de 4 clones con mas de un 97% de similitud con la variante J02020 de ASBVd; con la secuencia se corroboró la existencia de las variantes CF3, CF8, CF13. Estos resultados demuestran que aunque ASBVd no es eliminado mediante el uso de embriogénesis somática, la aplicación de esta tecnología permite inducir, proliferar y mantener por largo tiempo tejidos infectados para el estudio de este patógeno.

  9. Somatic embryogenesis in cell cultures of Glycine species.

    Science.gov (United States)

    Gamborg, O L; Davis, B P; Stahlhut, R W

    1983-08-01

    This report describes the development of procedures for the production of somatic embryos in cell cultures of Glycine species including soybean. The conditions for callus induction and initiation of rapidly growing cell suspension cultures were defined. Methods for inducing embryogenesis were tested on 16 lines of several Glycine species and cultivars of soybean. The SB-26 Culture of a G. soja gave the best results and was used in the experiments. Embryogenesis required the presence of picloram or 2,4-D. AMO 1618, CCC, PP-333 and Ancymidol enhanced the embryogenesis frequency. Plants of the G. soja (SB-26) were grown to maturity from seed-derived shoot tips. Characteristics of the plants are discussed.

  10. Somaclonal variation on in vitro callus culture potato cultivars Variação somaclonal in vitro em cultura de calos de cultivares de batata

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    Patricia N. Bordallo

    2004-06-01

    Full Text Available Synthetic seeds can be an alternative for those species in which botanical seeds are not viable. One of the major problems of in vitro plant cultivation is the high level of somaclonal variation. The most common factors affecting somaclonal variation are genotype, explant source, in vitro period and cultivation conditions in which the culture is established. In this work, calli were induced using leaf and stem explants of the commercial potato cultivars Achat, Baraka, Baronesa, Bintje, and Contenda in MS culture media supplemented with 1.65 mM of picloram and 11.5 mM of 2,4-D. Seventy and 90 days after induction, DNA samples of 40 calli were compared concerning the effects of the two explant (leaf and stem and two growth regulator sources on five potatoes cultivars. A total of 20 arbitrary sequence primers were evaluated. The RAPD pattern generated by these primers suggested a high percentage of polymorphic fragments among the five genotypes, indicating a high level of genetic variation among cultivars. Cultivar Baronesa showed the highest number of polymorphic fragments for all treatments. The cultivar Contenda showed the smallest somaclonal variation, for most of the treatments, except for the treatment which consisted of stem explants, picloram (1.65 mM application, and a 70-day period of callus formation. 'Contenda' is, therefore, the most suitable cultivar for synthetic seed production.A produção de sementes sintéticas pode ser uma altenativa para culturas, cuja produção de sementes botânicas não é viável. Um dos principais problemas do cultivo de planta in vitro é o alto nível de variação somaclonal resultante. Os fatores mais comuns que afetam a variação somaclonal são genótipo, fonte de explante e duração e condições de cultivo. Neste trabalho, calos foram induzidos utilizando explantes de folha e caule das cultivares comerciais de batata Achat, Baraka, Baronesa, Bintje e Contenda em meio de cultura MS, suplementado

  11. Hemoglobin promotes somatic embryogenesis in peanut cultures.

    Science.gov (United States)

    Jayabalan, N; Anthony, P; Davey, M R; Power, J B; Lowe, K C

    2004-02-01

    Critical parameters influencing somatic embryogenesis include growth regulators and oxygen supply. Consequently, the present investigation has focused on optimization of a somatic embryogenic system for peanut (Arachis hypogaea L.) through media supplementation with the auxin, picloram. The latter at 30 mg L(-1) was optimal for inducing regeneration of somatic embryos from cultured explants of zygotic embryos. In contrast, somatic embryogenesis did not occur in the absence of this growth regulator. An assessment has also been made of the beneficial effect on somatic embryogenesis and plant regeneration of the commercial hemoglobin (Hb) solution, Erythrogen. Hemoglobin at 1:50 and 1:100 (v:v) stimulated increases in mean fresh weight (up to a maximum of 57% over control), mean number of explants producing somatic embryos (15%) and mean number of somatic embryos per explant (29%).

  12. Effect of genotype, gelling agent, and auxin on the induction of somatic embryogenesis in sweet potato (Ipomoea batatas Lam.).

    Science.gov (United States)

    El Abidine Triqui, Zine; Guédira, Abdelkarim; Chlyah, Averil; Chlyah, Hassane; Souvannavong, Vongthip; Haïcour, Robert; Sihachakr, Darasinh

    2008-03-01

    Lateral buds of six cultivars of sweet potato were induced to form embryogenic callus in a culture medium solidified with two types of gelling agents, Agar or Gelrite, and supplemented with various concentrations of auxins, 2,4-D, 2,4,5-T and Picloram. Of the six cultivars screened, only three gave an embryogenic response. Best results with an average of 3.53% embryogenic response were obtained with the medium solidified with Agar, while in Gelrite only 0.45% of lateral buds gave rise to embryogenic callus. The interaction between the genotype and auxins was highly significant; particularly the optimal response was obtained with cv. Zho and 865 yielding 10.7 and 14.7% somatic embryogenesis, respectively, in the medium containing 2,4,5-T or Picloram. The plant conversion was dramatically improved by subculture of the embryogenic callus on the medium with the combination of 1 microM 2,4-D and 1 microM Kinetin or 5 microM ABA alone before transfer of mature embryos onto hormone-free medium. The embryogenic callus of sweet potato and its sustained ability to further regenerate plants have regularly been maintained for several years by frequent subculture in 5 microM 2,4,5-T or the combination of 10 microM 2,4-D and 1 microM BAP or kinetin. The embryo-derived plants seemed apparently genetically stable and similar to the hexaploid parental plants, based on morphological analysis and their ploidy level determined by using flow cytometry.

  13. Zeatin and Thidiazuron Induced Embryogenic Calli From In Vitro Leaf and Stem of Jojoba (Simmondsia chinensis).

    Science.gov (United States)

    El-Ashry, Amal Abd El-Latif; Gabr, Ahmed Mohamed Magdy; Bekheet, Shawky Abd El-Hamid

    2017-01-01

    Jojoba is a promising industrial plant, which recommended with pharmaceutical benefits. The present study was conducted to stimulate embryogenic calli formation from jojoba using zeatin and thidiazuron (TDZ), as well as determination of the antioxidant activity of proliferated calli. For callus induction, leaf and stem explants derived from in vitro grown shootlets, were cultured on Murashige and Skoog (MS) medium with different combinations of 0.5 mg L-1 benzyl adenine (BA) or kinetin with 2,4-Dichlorophenoxyacetic acid (2,4-D), Naphthalene acetic acid (NAA) and picloram at 0.5 or 1mg L-1. To stimulate embryogenic calli, friable callus were transferred to woody plant medium (WPM) supplemented with different concentrations of zeatin or TDZ. Antioxidant activity of different treatments was determined using hexane or petroleum ether extraction. Data was analyzed as mean±standard deviation (SD). The MS medium supplemented with 0.5 mg L-1 BA+0.5 or 1 mg L-1 picloram was the best treatment to obtain friable calli from both explants types. WPM medium supplemented with 2 mg L-1 zeatin gave the highest percentage of embryogenic calli derived from leaf explants. While the highest percentage of embryogenic calli derived from stem explants was registered using 1 or 4 mg L-1 TDZ containing medium. Embryogenic calli originated from leaves explants on 1.5 mg L-1 zeatin showed promising activity of antioxidant with hexane extraction. However, embryogenic calli originated from stem explants on 1 mg L-1 TDZ showed the highest antioxidant activity with petroleum ether extraction. TDZ has promising effect on embryogenic callus induction from stem explants. While, zeatin has promising effect on embryogenic callus induction from leaf explants.

  14. Applying a statewide geospatial leaching tool for assessing soil vulnerability ratings for agrochemicals across the contiguous United States.

    Science.gov (United States)

    Ki, Seo Jin; Ray, Chittaranjan; Hantush, Mohamed M

    2015-06-15

    A large-scale leaching assessment tool not only illustrates soil (or groundwater) vulnerability in unmonitored areas, but also can identify areas of potential concern for agrochemical contamination. This study describes the methodology of how the statewide leaching tool in Hawaii modified recently for use with pesticides and volatile organic compounds can be extended to the national assessment of soil vulnerability ratings. For this study, the tool was updated by extending the soil and recharge maps to cover the lower 48 states in the United States (US). In addition, digital maps of annual pesticide use (at a national scale) as well as detailed soil properties and monthly recharge rates (at high spatial and temporal resolutions) were used to examine variations in the leaching (loads) of pesticides for the upper soil horizons. Results showed that the extended tool successfully delineated areas of high to low vulnerability to selected pesticides. The leaching potential was high for picloram, medium for simazine, and low to negligible for 2,4-D and glyphosate. The mass loadings of picloram moving below 0.5 m depth increased greatly in northwestern and central US that recorded its extensive use in agricultural crops. However, in addition to the amount of pesticide used, annual leaching load of atrazine was also affected by other factors that determined the intrinsic aquifer vulnerability such as soil and recharge properties. Spatial and temporal resolutions of digital maps had a great effect on the leaching potential of pesticides, requiring a trade-off between data availability and accuracy. Potential applications of this tool include the rapid, large-scale vulnerability assessments for emerging contaminants which are hard to quantify directly through vadose zone models due to lack of full environmental data. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Pesticide Degrading Bacteria in Aquatic Environment: Bioprospecting and Evaluation of Biotechnological Potential

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    Daniel Rodrigues dos Santos

    2016-07-01

    Full Text Available Pesticides play an important role in the increase of productivity in agro-industry and the extensive use of these substances cause environmental, economic and social damage in time. Microbial activity is an essential part in the dynamics and the destination of pesticides in the environment. This research focuses in prospecting and characterizing bacterial strains which are potentially able to degrade/tolerate Atrazine, Chlorpyrifos, Methyl parathion and Picloram. Bacteria were isolated from water samples collected according to the degree of salinity along the Pacoti River's estuary (Ceara, located in the semi-arid region of northeastern Brazil. A total of 49 bacterial strains were isolated, all of which tolerated/ downgraded concentrations up to 200mg/L of picloram, atrazine and methyl parathion. Tested in pesticide mixtures, the percentage and tolerance level showed that 73% grew in concentrations up to 200mg/L, 17,4% tolerated/ downgraded up to 150ml/L and the remainder only grew in concentrations under 100ml/L. The strains which had the best performance against pesticides, by points, were P1 (13Db e 14D; P2 (10E; P3 (2M, 9M, 10M, 12Mb, 14M, 17M 18Mp 19M e 20M. A high percentage of isolates (67% expressed luminescence when exposed to the pesticides atrazine and methyl parathion in concentrations between 150 and 200ml/L. DOI: http://dx.doi.org/10.17807/orbital.v8i4.748

  16. Effect Of Explant Source And Different Medium Culture On Friable Embryogenic Callus Induction Of Four Cultivars Of Cassava Manihot Esculenta Crantz

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    Simplice Prosper Yandia

    2015-08-01

    Full Text Available In order to obtain Friable Embryogenic Callus FEC for protoplast isolation we have evaluated in this research the competance for Friable Embryogenic Callus FEC of four cassava cultivars M61033 Rendre Yalipe and Six-mois in media containing MS supplemented with 8mgl 24-D MS supplemented with 10 mgl BAP and GD supplemented with 12mgl picloram using apical bud AB and immature leaves lobes ILL as explants. In general in the medium GD12mgl picloram the highest efficiencies of FEC ranged from 58 to 87 and the highest score of FEC ranged from 4.2 to 5.4 with explants AB however we have observed with explants ILL the efficiencies of somatic embryos ranged form 41 to 75 and the score ranged from 4.1 to 4.4. The mediums MS28 mgl 24-D have induced with explants AB the efficiencies of FEC ranged from 43 to 57 and the score ranged from 3.1 to 3.8 however with ILL explants the efficiencies of FEC ranged from 39 to 49 and the score ranged from 2.9 to 3.7. The least FEC were observed in the medium MS210 mgl BAP with BA explants however the efficiencies ranged from 6 to 11 and the score ranged from 1.1 to 1.8. Whereas the efficiencies of FEC with ILL explants ranged from 4 to 7 and the score ranged from 0.5 to 0.8. All of four cultivars showed capability of producing FEC although their efficiency varied according to gonotype donors explants and medium taking into acount. Abbreviations GD Gressoff and Doy MS Murashige and Skoog 24-dichloro phenoxyacetic acid BAP Benzylamino-purin-Acid AB Apical Bud ILL Immature Leaves lobes

  17. In vitro propagation and elemental analysis of phyllanthus nirui L.: an anti-plasmodial plant

    International Nuclear Information System (INIS)

    Adusei-Fosu, K.

    2010-12-01

    Three accessions of Phyllanthus niruri from three different localities were assessed for their fruit or seed germination in vivo and in vitro as well as embryogenic calli and subsequent embryo induction. Accessions collected from Kwabenya, Kasoa or Aburi did not germinate when nursed. However, seeds from 3, 5 or 7 days dehisced fruits germinated with 7 days having the highest percentage (68.8%) of germination when nursed in the same substrate suggesting that there was fruit wall imposed dormancy. To improve percentage germination, seeds were cultured on MS medium supplemented with 0-1.2 mg/l BAP or kinetin. At this treatment, seed cultured on MS medium supplemented with 1.2 mg/l had the highest percentage (61.1% ) of germination. Alternate regeneration via nodal cuttings cultured on MS basal medium supplemented with BAP with NAA or IBA resulted in multiple shoot induction which augurs well for rapid clonal multiplication. Additionally, regeneration via somatic embryogenesis using leaf lobe explants cultured on MS, OK W, Schenk basal medium with vitamins supplemented with 2,4-0 or Picloram resulted in only callus induction. Callus induction was high when concentrations of (0.2-1.0 mg/l) 2,4-0 were used with concentrations of (2.0-3.0 mg/l) Picloram was able to induce calli. The transfer of calli to MS medium supplemented with BAP resulted in multiple shoot regeneration. Calli also grew in size and were weighed after three series of subcultures indicating that they could be used for extraction of antiplasmodial active ingredients. Instrumental Neutron Activation Analysis (lNAA) revealed the presence of five macro and four micro nutrients but no toxic element making P. niruri useful as a medicinal plant. (au)

  18. Analysis of airborne pesticides from different chemical classes adsorbed on Radiello® Tenax® passive tubes by thermal-desorption-GC/MS.

    Science.gov (United States)

    Raeppel, Caroline; Fabritius, Marie; Nief, Marie; Appenzeller, Brice M R; Briand, Olivier; Tuduri, Ludovic; Millet, Maurice

    2015-02-01

    An analytical methodology using automatic thermal desorption (ATD) and GC/MS was developed for the determination of 28 pesticides of different chemical classes (dichlobenil, carbofuran, trifluralin, clopyralid, carbaryl, flazasulfuron, mecoprop-P, dicamba, 2,4-MCPA, dichlorprop, 2,4-D, triclopyr, cyprodinil, bromoxynil, fluroxypyr, oxadiazon, myclobutanil, buprofezin, picloram, trinexapac-p-ethyl, ioxynil, diflufenican, tebuconazole, bifenthrin, isoxaben, alphacypermethrin, fenoxaprop and tau-fluvalinate) commonly used in nonagricultural areas in atmospheric samples. This methodology was developed to evaluate the indoor and outdoor atmospheric contamination by nonagricultural pesticides. Pesticides were sampled passive sampling tubes containing Tenax® adsorbent. Since most of these pesticides are polar (clopyralid, mecoprop-P, dicamba, 2,4-MCPA, dichlorprop, 2,4-D, triclopyr, bromoxynil, fluroxypyr, picloram, trinexapac-p-ethyl and ioxynil), a derivatisation step is required. For this purpose, a silylation step using N-(t-butyldimethylsilyl)-N-methyltrifluoroacetamide (MtBSTFA) was added before thermal desorption. This agent was chosen since it delivers very specific ions on electronic impact (m/z = M-57). This method was established with special consideration for optimal thermal desorption conditions (desorption temperature, desorb flow and duration; trap heating duration and flow; outlet split), linear ranges, limits of quantification and detection which varied from 0.005 to 10 ng and from 0.001 to 2.5 ng, respectively, for an uncertainty varied from 8 to 30 %. The method was applied in situ to the analysis of passive tubes exposed during herbicide application to an industrial site in east of France.

  19. Regeneración de nogal cafetero (Cordia alliodora (Ruiz y Pav. Oken, a partir de organogénesis indirecta

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    Lina María Londoño-Giraldo

    2013-07-01

    Full Text Available En el estudio, utilizando organogénesis indirecta a partir de hoja cotiledonar se evaluó la regeneración de Cordia alliodora (Ruiz y Pav Oken, un árbol nativo de uso industrial, medicinal y ornamental. Para la desinfección de las semillas se utilizó hipoclorito de sodio al 3% por 15 min acompañado de la adición del preservante para plantas PPM® al medio de cultivo. En la fase de formación de callo fueron evaluados tres reguladores de crecimiento: BAP, Picloram y 2,4-D en concentraciones desde 0.5 hasta 12.5 mg/lt en condiciones de luz (12 h y oscuridad, obteniendo callo en todas ellos. Los callos fueron transferidos a los medios de cultivo (mg/lt: BAP (1, 2,4-D (7.5, Picloram (7.5 y a medio de cultivo sin reguladores de crecimiento. Después de 30 días de cultivo la mayoría de los callos se oxidaron, no obstante algunos cultivados en BAP (10 mg/lt mostraron brotes organogénicos. Los resultados obtenidos sugieren una vía de regeneración in vitro posible mediante organogénesis indirecta a partir de hoja cotiledonar y permiten proponer investigaciones posteriores para avanzar en la regeneración exitosa a partir de esta u otras técnicas de regeneración n vitro.

  20. Carbon source dependent somatic embryogenesis and plant regeneration in cotton, Gossypium hirsutum L. cv. SVPR2 through suspension cultures.

    Science.gov (United States)

    Ganesan, M; Jayabalan, N

    2005-10-01

    Highly reproducible and simple protocol for cotton somatic embryogenesis is described here by using different concentrations of maltose, glucose, sucrose and fructose. Maltose (30 g/l) is the best carbon source for embryogenic callus induction and glucose (30 g/l) was suitable for induction, maturation of embryoids and plant regeneration. Creamy white embryogenic calli of hypocotyl explants were formed on medium containing MS basal salts, myo-inositol (100 mg/l), thiamine HCI (0.3 mg/l), picloram (0.3 mg/l), Kin (0.1 mg/l) and maltose (30 g/l). During embryo induction and maturation, accelerated growth was observed in liquid medium containing NH3NO4 (1 g/l), picloram (2.0 mg/l), 2 ip (0.2 mg/l), Kin (0.1 mg/l) and glucose (30 g/l). Before embryoid induction, large clumps of embryogenic tissue were formed. These tissues only produced viable embryoids. Completely matured somatic embryos were germinated successfully on the medium fortified with MS salts, myo-inositol (50 mg/l), thiamine HCl (0.2 mg/l), GA3 (0.2 mg/l), BA (1.0 mg/l) and glucose (30 g/l). Compared with earlier reports, 65% of somatic embryo germination was observed. The abnormal embryo formation was highly reduced by using glucose (30 g/l) compared to other carbon sources. The regenerated plantlets were fertile but smaller in height than the seed derived control plants.

  1. Avaliação de diferentes herbicidas para erradicação química de coqueiros infectados com resinose Herbicide selection for chemical eradication of coconut palms infected with stem-bleeding

    Directory of Open Access Journals (Sweden)

    H.R. Fontes

    2009-01-01

    Full Text Available Objetivou-se neste trabalho selecionar herbicidas que possam ser utilizados na erradicação química de coqueiros infectados com resinose. O experimento foi instalado no município de Neópolis - SE, no período de junho a julho de 2007. Utilizou-se uma população de coqueiros da variedade anão-verde, implantada há 11 anos. O delineamento experimental foi o inteiramente casualizado, em parcelas subdivididas no tempo, com cinco repetições (cada unidade experimental foi composta por um coqueiro infectado. Os tratamentos foram formados pela combinação de dez tratamentos herbicidas {MSMA (36 g por planta; glyphosate (18 g por planta; paraquat (10 g por planta; [2,4-D + picloram] (18 + 1,125 g por planta; [2,4-D + picloram] + paraquat ([9 + 0,5625] + 5 g por planta; MSMA + glyphosate (18 + 9 g por planta; MSMA + paraquat (18 + 5 g por planta; glyphosate + paraquat (9 + 5 g por planta; [2,4-D + picloram] + MSMA ([9 + 0,5625] + 18 g por planta; tratamento controle (testemunha sem aplicação} e de quatro épocas de avaliação (7, 14, 21 e 28 dias após a aplicação dos tratamentos herbicidas. Os herbicidas foram injetados no estipe dos coqueiros em um furo de 25 cm de profundidade, 5 cm de diâmetro e inclinação de 45º, localizado a 1,0 m de altura. A aplicação foi realizada por intermédio de uma seringa graduada, imediatamente após a abertura dos furos, sendo os herbicidas aplicados sem diluição. Foram realizadas quatro avaliações da dessecação dos coqueiros, aos 7, 14, 21 e 28 dias após a aplicação dos tratamentos (DAA. O herbicida MSMA foi o que resultou na dessecação mais rápida dos coqueiros doentes, além de promover a morte de todas as plantas avaliadas, sendo por isso o tratamento mais indicado na continuação dos estudos visando à proposição de uma técnica para a erradicação química de coqueiros infectados com resinose.The objective of this work was to select herbicides that can be used to chemically

  2. Effect of irradiation and colchicine on callus and somatic embryo formation in cassava (Manihot esculenta Crantz)

    International Nuclear Information System (INIS)

    Dzimega, D. A.

    2012-06-01

    A study was conducted to assess the mutagenic effect of gamma radiation on sprouting and height in four local cassava accessions. The four cassava accessions were assessed for their callus induction and somatic embryo formation ability from leaf lobes from gamma irradiated stakes as well as colchicine treated leaf lobes on different concentrations of plant growth regulators, incorporated into Murashige and skoog, (1962) (MS) basal medium. The cassava accessions were irradiated at 0, 32, 35, 45 and 50 Gy and planted in pots filled with loamy soil. The height of the shoots was measured with rule after sprouting. The leaf lobes were collected from the shoots and cultured on MS medium supplemented with 8 mg/l 2, 4-D and 16 mg/l Picloram. Another set of leaf lobes were treated with 0.0, 0.05, 0.1, 0.2, 0.25 g/l colchicine for one hour and thereafter culture on MS medium supplemented with 8 mg/l 2,4-D and 16 mg/l Picloram as described above. Callus induction from leaf lobes in 45 and 50 Gy were significantly (p≤0.05) affected by the irradiation. On the other hand, Callus induction from leaf lobes in 0.1-0.25 g/l colchicine were significantly (p≤0.05) affected by the mutagenic treatment whereas callus induced from leaf lobes in 0.05 g/l colchicine was not significantly (p≤0.05) affected. Callus induced on 8 mg/l 2, 4-D and 16 mg/l picloram gave the best response in Ankrah and all control tested while Tomfa recorded the least. Colchicine at a concentration of 0.05 g/l and radiation dose of 32 Gy treatments gave the best response of callusing. Callus induction decreased with increasing colchicine concentration and gamma irradiation. Callus derived from irradiated and colchicine leaf lobes appeared soft but friable and tiny, compact, respectively, predominately with creamy to brown colouration. Calli obtained were sub-cultures on embryo regeneration medium consisting of MS supplemented with 0.01mg/1 NAA and o.1 mg/1 BAP. There was no plantlet regeneration. Instead

  3. Embriogénesis somática y producción de callo embriogénico friable de dos cultivares de yuca (Manihot esculenta Crantz

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    Juan Camilo Ochoa

    2012-07-01

    Full Text Available Título en ingles: Somatic Embryogenesis and friable embryogenic callus production in two cassava cultivars (Manihot esculenta Crantz Resumen: La yuca (Manihot esculenta Crantz es un cultivo de alta importancia en países tropicales. La transformación genética de yuca ha sido posible desde hace 15 años mediante la producción que callo embriogénico friable (CEF a partir de embriones somáticos. En el presente trabajo se evalúan la inducción de embriones somáticos usando tres diferentes auxinas sintéticas y la producción de CEF a partir de éstos en los cultivares de yuca SG107-35 y BRA685. Estos cultivares son resistentes a la bacteriosis vascular de yuca cuyo agente causal es Xanthomonas axonopodis pv. manihotis, una de las principales limitantes del cultivo. Los resultados obtenidos muestran que en ambos cultivares la hormona Picloram a una concentración de 12 mg/l fue más eficiente que 2,4-D y Dicamba para producir embriones somáticos. Adicionalmente se consiguió la producción de CEF y la regeneración de plantas mediante embriogénesis somática en el cultivar BRA685. Los resultados del presente trabajo son importantes para evaluar la transformabilidad de distintos cultivares de yuca. Actualmente este número es bastante reducido principalmente porque la producción de CEF es fuertemente influenciada por el genotipo. Por tal razón solo se transforma de manera rutinaria y eficiente en el cultivar 60444. La posibilidad de transformación de distintos cultivares de yuca permitirá explotar la enorme variabilidad del cultivo, invitándonos a aumentar los esfuerzos para mejorar y universalizar los protocolos de transformación de yuca. Palabras clave: Picloram, regeneración, dependencia del genotipo.  Abstract: The cassava (Manihot esculenta Crantz crop has a very important role as a food, feed and a raw material in developing countries; therefore it is a priority to develop technologies oriented to the solution of problems and

  4. Toxicidade aguda de herbicidas a tilápia (Oreochromis niloticus Acute toxicity to herbicides to Oreochromis niloticus

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    R.G. Botelho

    2009-01-01

    Full Text Available Esta pesquisa teve como objetivo avaliar a sensibilidade de alevinos de Oreochromis niloticus a diversos herbicidas. Para isso, foram realizados dois ensaios, sendo, no primeiro, avaliadas concentrações de atrazina (0; 2,5; 5; 10; e 20 mg L-1, visando a determinação da concentração letal a 50% dos indivíduos (CL50, e, no segundo, a sensibilidade às mesclas dos herbicidas alachlor + atrazina (5,33 + 5,33 mg L-1, diuron + MSMA (5,33 + 2,13 mg L-1, paraquat (1,33 mg L-1 e 2,4-D + picloram (1,28 + 0,34 mg L-1, com contagem de mortes 96 horas após exposição aos produtos. No primeiro ensaio foi observado elevado declínio na sobrevivência dos alevinos a partir de 3 mg L-1 do herbicida atrazina, com CL50 estimada de 5,02 mg L-1. No segundo, a mistura alachlor + atrazina promoveu o maior efeito de mortalidade sobre os alevinos de tilápia. Com 72 horas de exposição, a escala de intoxicação evidenciou redução nos números de indivíduos de, aproximadamente, 17,4% para os produtos paraquat, 2,4-D + picloram e diuron + MSMA e de 100% para alachlor + atrazina. Os dados permitem concluir que a CL50 obtida para o atrazina é inferior àquela mencionada como tóxica para truta e que a mistura alachlor + atrazina pode ser caracterizada como de risco para O. niloticus, mesmo quando aplicada em doses normais de uso.Two assays were carried out to evaluate Oreochromis niloticus sensitivity to different herbicides. In the first experiment, atrazin concentrations (0; 2.5; 5; 10 and 20 mg L-1 were evaluated aiming to determine lethal concentration (LC50 to O. niloticus. In the second assay, the effects of the herbicide mixtures alachlor + atrazin (5.33 + 5.33 mg L-1, diuron + MSMA (5.33 + 2.13 mg L-1 , paraquat (1.33 mg L-1 and 2,4-D + picloran (1.28 + 0.34 mg L-1 , were evaluated on O. niloticus survival after 96 h of exposure. In the first assay, a sharp decrease in fingerlings survival was observed from 3 mg L-1 of atrazin with CL50 value of 5

  5. Estimation of herbicide bioconcentration in sugarcane (Saccharum officinarum L.

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    Antonio Luiz Cerdeira

    2015-04-01

    Full Text Available Sugarcane is an important crop for sugar and biofuel production in Brazil. Growers depend greatly on herbicides to produce it. This experiment used herbicide physical-chemical and sugarcane plant physiological properties to simulate herbicide uptake and estimate the bioconcentration factor (BCF. The (BCF was calculated for the steady state chemical equilibrium between the plant herbicide concentration and soil solution. Plant-water partition coefficient (sugarcane bagasse-water partition coefficient, herbicide dilution rate, metabolism and dissipation in the soil-plant system, as well as total plant biomass factors were used. In addition, we added Tebuthiuron at rate of 5.0kg a.i. ha-1 to physically test the model. In conclusion, the model showed the following ranking of herbicide uptake: sulfentrazone > picloram >tebuthiuron > hexazinone > metribuzin > simazine > ametryn > diuron > clomazone > acetochlor. Furthermore, the highest BCF herbicides showed higher Groundwater Ubiquity Score (GUS index indicating high leaching potential. We did not find tebuthiuron in plants after three months of herbicide application

  6. Flavonoid Production, Growth and Differentiation of Stelechocarpus burahol (Bl.) Hook. F. and Th. Cell Suspension Culture.

    Science.gov (United States)

    Aini Habibah, Noor; Moeljopawiro, Sukarti; Dewi, Kumala; Indrianto, Ari

    2017-01-01

    Stelechocarpus burahol is a plant containing flavonoid compounds that have the potential for use as an antihyperuricemic for gout medication. This study was performed to assess flavonoid production, growth and cell differentiation of S. burahol in cell suspension culture. Mesocarp was planted in Murashige and Skoog (MS) medium supplemented with 7.5 mg L-1 picloram for the induction of callus. Non-embryonic callus obtained was used in the formation of cell suspension cultures. Growth of cells was determined by fresh and dry weights. During the culturing, the fresh weight, dry weight and flavonoid content were determined as a result of culture status. The growth of the S. burahol cell suspension was slow, the stationary phase occurred at 30 days. The production of flavonoids was not in line with the growth of cells and the maximum production occurred on the 15th day of the log phase. The globular-shaped cells dominated the cell suspension culture at all ages. Fluorescein diacetate (FDA) staining of cells derived from cell cultures aged for 36 days showed that some cells were still viable. The results show that flavonoid production, growth and cell differentiation of a S. burahol cell suspension culture differed according to the culture age.

  7. EFFECT OF PHYSIOLOGICAL AGE AND GROWTH REGULATORS ON CALLUS BROWNING OF COCONUT ENDOSPERM CULTURE IN VITRO

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    LAZARUS AGUS SUKAMTO

    2011-01-01

    Full Text Available The possibility of physiological age and growth regulators affecting callus browning ofcoconut endosperm was investigated. Solid endosperm explants of four coconut fruits fromsame brunches of two coconut cultivars “Samoan Dwarf ” were grown on modified Murashigeand Skoog (MS formula with addition of 10 mg l putresine, 2.50 g l activated charcoal (AC,1.70 g l phytagel, 0, 10 , 10 , 10 , 10 M 2,4-dichlorophenoxyacetic acid (2,4-D or 4-amino-3,5,6-trichloropicolinic acid (Picloram combined with 10 M 6-benzylaminopurine (BA.Callogenesis occurred on 98.83% of explants. Callus browning between different physiologicalages (antipodal and micropylar tissues of coconut endosperm at 9, 26 and 31 weeks of culture(WOC was significantly different, but not at 16 and 21 WOC. Auxins of 2,4-D and Picloramdid not affect significantly callus browning of endosperm cultures. Auxin doses at 10 , 10 , and10 M decreased significantly callus browning at 9 and 16 WOC, respectively, but at 10 Mbrowning was less significant compared to other doses at 21 WOC. Auxin dose at 10 M causedless significant browning compared to other doses at 31 WOC. The addition of BA decreasedsignificantly callus browning at 9 WOC, but did not affect callus browning thereafter.

  8. Factores que influyen en la embriogénesis somática in vitro de palmas (Arecaceae

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    María Viñas

    2011-07-01

    Somatic embryogenesis (SE is an in vitro developmental pathway that exhibits a number of advantages over other techniques for regeneration of palms. This technique has great potential to overcome the limitations observed when trying to propagate these plants clonally using basal buds. Despite the known recalcitrance of palms for in vitro culture, good results can be obtained by using the appropriate growth regulators, explant type and developmental stage, as well as responsive genotypes. This has been partially observed in Phoenix dactylifera (date palm, Elaeis guineensis (African oil palm, Bactris gasipaes (peach palm and Cocos nucifera (coconut. Efficient protocols have been also generated in less-studied palms, such as Geonoma gamiova (an ornamental palm, Euterpe edulis (Assai palm and Areca catechu (areca palm. Induction of  SE has been achieved mainly through the use of auxins. Of these, 2,4-dichlorophenoxyacetic acid (2,4-D has been used most frequently, although in some cases (such as in peach palm and African oil palm picloram and dicamba have been employed also with good results. The most commonly used explants are young inflorescences, apical buds and leaf-basal segments. Explant size and culture medium also play an important role in obtaining good results. This review presents a compilation of the most important publications on SE in this plant family and the effect of various factors on induction and development of this pathway. Key words: Culture medium; explants; genotype; plant growth regulators; regeneration

  9. Induced chlorophyll variation in pineapple c v. 'queen' by gamma irradiation (60Cobalt)

    International Nuclear Information System (INIS)

    Valencia, Lolita DC.

    2012-01-01

    Irradiation using gamma rays ( 60 Cobalt) coupled with in vitro culture techniques was undertaken to induce variation or mutation in pineapple. Calli from crown meristem tips of pineapple cv 'Queen' [Ananas comosus (L.) Merr.] were initiated using Murashiege and Skoog's basal meduim supplemented with 10mg/liter 4-amino-3,5,6-trichloro-2-pyrodinecarboxylic acid (Picloram). High percentage of growth and shoot proliferation was observed in basal medium supplemented with 50 μM benzene adenine purine (BAP) and 10 μM gibberrelic acid (GA) after 8 weeks in vitro. Regenerants derived from shoots using different doses of gamma rays (0, 5, 10, 15, 20, 25 and 30 Gy) were evaluated under laboratory conditions. Of the different doses, 15 Gy produced the most variegation in young shoots (chlorophyll variants) maintained in vitro. The variants appeared to have yellow and green color combinations of the young leaves of pineapple 'Queen' variety. When transplanted inside the greenhouse, high percentage of plantlets survival was observed, ranging from 90-95%. Of the different irradiation doses, variegation in young leaves was observed at 15, 20, 25 and 30 Gy. Further assessment on the effect of irradiation is currently being unertaken under screen house conditions. The variants produced could serve a basis for selection of ornamental-type pineapple. In addition, protocols developed on the use of in vitro culture techniques could be utilized as a tool for induced mutation breeding in pineapple. (author)

  10. In vitro regeneration of Amazonian pineapple (Ananas comosus plants ecotype Gobernadora

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    Héctor Alexander Blanco Flores

    2017-01-01

    Full Text Available There are a number of pineapple (Ananas comosus cultivars and ecotypes of local commercial importance in Venezuela, among them the Amazonian ones, cultivated mainly by the aboriginal Piaroa, are of relevance. They sow the propagules, which restricts the availability of material for large-scale cultivation. This limitation was approached by plant tissue culture for in vitro propagation of Amazonian pineapple plants, Gobernadora ecotype, through somatic embryogenesis (ES and adventitious organogenesis (OA. Basal and intermediate sections of leaves were tested. Only the leaf base sections (FBS were morphogenically induced. The highest number of vitroplants (1.58 plants / explant was obtained from the embryogenic callus induced in MS medium with Picloram 10 mg.L-1 + Thidiazuron 2 mg.L-1, transferred to MS medium without hormones. In the organogenic process, the highest number of plants/explants (5 was obtained directly in MS with naphthaleneacetic acid 5 mg.L-1 + benzylaminopurine 0.25 mg.L-1, transferred to MS. The latter being the best in vitro culture system due to its productivity and for being a method that minimizes somaclonal variation.

  11. Simultaneous analysis of pesticides from different chemical classes by using a derivatisation step and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Raeppel, Caroline; Nief, Marie; Fabritius, Marie; Racault, Lucie; Appenzeller, Brice M; Millet, Maurice

    2011-11-04

    This work presents a new method to analyse simultaneously by GC-MS 31 pesticides from different chemical classes (2,4 D, 2,4 MCPA, alphacypermethrin, bifenthrin, bromoxynil, buprofezin, carbaryl, carbofuran, clopyralid, cyprodinil, deltamethrin dicamba, dichlobenil, dichlorprop, diflufenican, diuron, fenoxaprop, flazasulfuron, fluroxypyr, ioxynil, isoxaben, mecoprop-P, myclobutanil, oryzalin, oxadiazon, picloram, tau-fluvalinate tebuconazole, triclopyr, trifluralin and trinexapac-p-ethyl). This GC-MS method will be applied to the analysis of passive samplers (Tenax(®) tubes and SPME fiber) used for the evaluation of the indoor and outdoor atmospheric contamination by non-agricultural pesticides. The method involves a derivatisation step for thermo-labile or polar pesticides. Different agents were tested and MtBSTFA (N-(t-butyldimethylsilyl)-N-methyltrifluoroacetamide), a sylilation agent producing very specific fragments [M-57], was retained. However, diuron could not be derivatised and the isocyanate product was used for identification and quantification. Pesticides which did not need a derivatisation step were not affected by the presence of the derivatisation agent and they could easily be analysed in mixture with derivatised pesticides. The method can be coupled to a thermal-desorption unit or to SPME extraction for a multiresidue analysis of various pesticides in atmospheric samples. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Antimicrobial activity of Anonna mucosa (Jacq. grown in vivo and obtained by in vitroculture

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    Thiago José de Souza Barboza

    2015-09-01

    Full Text Available Brazilian flora includes numerous species of medicinal importance that can be used to develop new drugs. Plant tissue culture offers strategies for conservation and use of these species allowing continuous production of plants and bioactive substances. Annona mucosa has produced substances such as acetogenins and alkaloids that exhibit antimicrobial activities. The widespread use of antibiotics has led to an increase in multidrug-resistant bacteria, which represents a serious risk of infection. In view of this problem, the aim of this work was to evaluate the antibacterial potential of extracts of A. mucosa obtained by in vitro techniques and also cultured under in vivo conditions. Segments from seedlings were inoculated onto different culture media containing the auxin picloram and the cytokinin kinetin at different concentrations. The calluses obtained were used to produce cell suspension cultures. The materials were subjected to methanol extraction and subsequent fractionation in hexane and dichloromethane. The antimicrobial activity against 20 strains of clinical relevance was evaluated by the macrodilution method at minimum inhibitory and minimum bactericidal concentrations. The extracts showed selective antimicrobial activity, inhibiting the growth of Streptococcus pyogenes and Bacillus thuringiensis at different concentrations. The plant tissue culture methods produced plant materials with antibacterial properties, as well as in vivo grown plants. The antibacterial activity of material obtained through biotechnological procedures of A. mucosa is reported here for the first time.

  13. Development of California Public Health Goals (PHGs) for chemicals in drinking water.

    Science.gov (United States)

    Howd, R A; Brown, J P; Morry, D W; Wang, Y Y; Bankowska, J; Budroe, J D; Campbell, M; DiBartolomeis, M J; Faust, J; Jowa, L; Lewis, D; Parker, T; Polakoff, J; Rice, D W; Salmon, A G; Tomar, R S; Fan, A M

    2000-01-01

    As part of a program for evaluation of environmental contaminants in drinking water, risk assessments are being conducted to develop Public Health Goals (PHGs) for chemicals in drinking water, based solely on public health considerations. California's Safe Drinking Water Act of 1996 mandated the development of PHGs for over 80 chemicals by 31 December 1999. The law allowed these levels to be set higher or lower than federal maximum contaminant levels (MCLs), including a level of zero if data are insufficient to determine a specific level. The estimated safe levels and toxicological rationale for the first 26 of these chemicals are described here. The chemicals include alachlor, antimony, benzo[a]pyrene, chlordane, copper, cyanide, dalapon, 1,2-dichlorobenzene, 1,4-dichlorobenzene, 2,4-D, diethylhexylphthalate, dinoseb, endothall, ethylbenzene, fluoride, glyphosate, lead, nitrate, nitrite, oxamyl, pentachlorophenol, picloram, trichlorofluoromethane, trichlorotrifluoroethane, uranium and xylene(s). These risk assessments are to be considered by the State of California in revising and developing state MCLs for chemicals in drinking water (which must not exceed federal MCLs). The estimates are also notable for incorporation or consideration of newer guidelines and principles for risk assessment extrapolations.

  14. Induksi Mutasi Kalus Embriogenik Gandum (Triticum aestivum L. melalui Iradiasi Sinar Gamma untuk Toleransi Suhu Tinggi

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    Ryan Budi Setiawan

    2015-06-01

    Full Text Available Mutation techniques through gamma ray irradiation is useful to support breeding programs for genetic improvement of wheat. Genetic improvement on tolerance to high temperatures is necessary for development of wheat in Indonesia. The purpose of this study was to determine the level of radiosensitivity to be used as the basis for the induction of mutations by gamma ray irradiation on embryogenic callus to obtain putative mutants with high temperature tolerance. Explants used were embryogenic callus cultured on MS medium containing 30 g L-1 sukrosa, 2 g L-1 gelrite, 2 mg L-1 2.4D and 1 mg L-1 picloram. Culture incubated for 6 weeks with temperature 20±4 oC in the room culture. Five irradiation doses (10, 20, 30, 40 and 50 Gy were used in radiosensitivity testing. A factorial, completely randomized design was applied to the experiment. The first factor was selection temperature with three levels (25, 30 and 35 oC, and the second factor was doses of gamma ray iradiation with three levels (10, 20, and 30 Gy. The result showed that radiosensitivity levels varied among varieties, LD20: 7.79 to 18.96 Gy and LD50: 24.29-33.63 Gy. Selayar variety which has highest sensitivity value compared with Dewata and Nias. Increasing doses of iradiation and temperature decrease survival of embryogenic callus, number of embryos, and percentage of germinated plantlets. Based on in vitro selection using high temperature (25, 30, and 35 oC, the obtained 19 putative mutants were derived from embryos that appear on the surface of embryogenic callus survival after irradiation and high temperature selection.Keywords: in vitro selection, putative mutant, radiosensitivity, somatic embryo

  15. Experimental control of Spanish broom (Spartium junceum invading natural grasslands

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    Cristina Sanhueza

    2012-12-01

    Full Text Available A group of legumes generically known as brooms are among the most successful shrubs invading grasslands in South America and otherregions. These species share a set of biological features that enhance their invasiveness, such as abundant and long-lasting seed banks,aggressive root systems and rapid growth, combined with their ability for re-sprouting after cutting or burning and for avoiding herbivores.They grow in dense stands that exclude native vegetation and are able to change ecological processes, increasing fire frequency and intensity,and fixing atmospheric nitrogen. The Spanish broom (Spartium junceum is a shrub native form the Mediterranean that was introduced intothe Argentine Pampas grasslands where it spreads over remnants of pristine ecosystems, threatening their biodiversity. This paper reports theresults obtained after an adaptive management strategy aimed at controlling this species in a nature reserve, and compares the efficiency ofdifferent mechanical and chemical control techniques in terms of the number of plants killed and the effects on surrounding vegetation andon the recruitment of broom seedlings. Control was implemented in two phases, the first included three treatments: i cut at the base of theplant, ii cut followed by the immediate application of Togar (Picloram 3% + Triclopyr 6%, at a 5% dilution in diesel oil on top of the cut stump, and iii foliar spraying with Togar. The follow-up treatments, implemented one year later, consisted of spraying the re-sprouts with Togar (5% in diesel oil or Glyphosate 36% (2% in water. The best option in terms of controlling Spanish broom was spraying the resprouts with Togar which gave 100% mortality of the treated plants, compared with values of 40% - 100% re-sprouting for the other optionstested. None of the methods was associated with an increase in seedling recruitment, nor with significant changes in the vegetation in the immediate vicinity of the controlled brooms.

  16. Water-quality assessment of the Trinity River Basin, Texas - Review and analysis of available pesticide information, 1968-91

    Science.gov (United States)

    Ulery, R.L.; Brown, M.F.

    1995-01-01

    In 1991 the Trinity River Basin study unit was among the first 20 study units in which work began under full-scale program implementation of the National Water-Quality Assessment Program. A retrospective assessment was undertaken to review and analyze existing pesticide data and related environmental factors. Population and land-use data indicate human modifications to the landscape and hydrologic system of the study area during the period 1968–91. A variety of crops treated with pesticides were identified, with wheat and cotton accounting for the largest number of acres treated annually (541,250 and 519,870 acres, respectively). Agricultural-use estimates for the later period covered by this report (1988–90) indicate that 105 different pesticides were used and that 24 pesticides accounted for 75 percent of average agricultural use in the study area. Sorghum was treated by the largest number of the 24 mostused pesticides, and cotton was treated by the second largest number of those pesticides. Dimethoate and methyl parathion were the most heavily used of the organophosphate class pesticides. The herbicide 2,4–D was the most heavily used chlorophenoxy pesticide. Carbamate pesticides are used extensively in the study area, with carbaryl, carbofuran, methomyl, and thiodicarb accounting for the majority of the use of this class of pesticide. Miscellaneous pesticides included alachlor, arsenic acid, picloram, and glyphosate, among others. The data indicate that herbicide use generally is proportionally higher in the study area than in the Nation, and that insecticide use in the study area generally is proportionally lower than in the Nation.

  17. The pea branching RMS2 gene encodes the PsAFB4/5 auxin receptor and is involved in an auxin-strigolactone regulation loop.

    Science.gov (United States)

    Ligerot, Yasmine; de Saint Germain, Alexandre; Waldie, Tanya; Troadec, Christelle; Citerne, Sylvie; Kadakia, Nikita; Pillot, Jean-Paul; Prigge, Michael; Aubert, Grégoire; Bendahmane, Abdelhafid; Leyser, Ottoline; Estelle, Mark; Debellé, Frédéric; Rameau, Catherine

    2017-12-01

    Strigolactones (SLs) are well known for their role in repressing shoot branching. In pea, increased transcript levels of SL biosynthesis genes are observed in stems of highly branched SL deficient (ramosus1 (rms1) and rms5) and SL response (rms3 and rms4) mutants indicative of negative feedback control. In contrast, the highly branched rms2 mutant has reduced transcript levels of SL biosynthesis genes. Grafting studies and hormone quantification led to a model where RMS2 mediates a shoot-to-root feedback signal that regulates both SL biosynthesis gene transcript levels and xylem sap levels of cytokinin exported from roots. Here we cloned RMS2 using synteny with Medicago truncatula and demonstrated that it encodes a putative auxin receptor of the AFB4/5 clade. Phenotypes similar to rms2 were found in Arabidopsis afb4/5 mutants, including increased shoot branching, low expression of SL biosynthesis genes and high auxin levels in stems. Moreover, afb4/5 and rms2 display a specific resistance to the herbicide picloram. Yeast-two-hybrid experiments supported the hypothesis that the RMS2 protein functions as an auxin receptor. SL root feeding using hydroponics repressed auxin levels in stems and down-regulated transcript levels of auxin biosynthesis genes within one hour. This auxin down-regulation was also observed in plants treated with the polar auxin transport inhibitor NPA. Together these data suggest a homeostatic feedback loop in which auxin up-regulates SL synthesis in an RMS2-dependent manner and SL down-regulates auxin synthesis in an RMS3 and RMS4-dependent manner.

  18. Evaluation of haemoglobin (erythrogen): for improved somatic embryogenesis and plant regeneration in cotton (Gossypium hirsutum L. cv. SVPR 2).

    Science.gov (United States)

    Ganesan, M; Jayabalan, N

    2004-10-01

    Somatic embryogenesis in cotton (Gossypium hirsutum L.) is accelerated when the plant regeneration medium is supplemented with haemoglobin (erythrogen). In cotton SVPR 2 lines, a higher frequency of embryoid formation was observed when the medium contained 400 mg/l haemoglobin. Fresh weight of the callus, rate of embryoid induction, number of embryoids formed and the percentage of plant regeneration from somatic embryos were increased. Among the two different cultivars tested, MCU 11 showed no response to the presence of haemoglobin when compared to SVPR 2, and embryogenic callus formation was completely absent in the former. Medium containing MS salts, 100 mg/l myo-inositol , 0.3 mg/l thiamine-HCL, 0.3 mg/l Picloram (PIC), 0.1 mg/l kinetin and 400 mg/l haemoglobin effected a better response with respect to embryogenic callus induction. After 8 weeks of culture, a high frequency of embryoid induction was observed on medium containing MS basal salts, 100 mg/l myo-inositol, 0.3 mg/l PIC , 0.1 mg/l isopentenyl adenine, 1.0 g/l NH4NO3 and 400 mg/l haemoglobin. Plant regeneration was observed in 75.8% of the mature somatic embryos, and whole plant regeneration was achieved within 6-7 months of culture. The regenerated plantlets were fertile and similar to in vivo-grown, seed-derived plants except that they were phenotypically smaller. A positive influence of haemoglobin was observed at concentrations up to 400 mg/l at all stages of somatic embryogenesis. The increase in the levels of antioxidant enzyme activities, for example superoxide dismutase and peroxidase, indicated the presence of excess oxygen uptake and the stressed condition of the plant tissues that arose from haemoglobin supplementation. This increased oxygen uptake and haemoglobin-mediated stress appeared to accelerate somatic embryogenesis in cotton.

  19. In-vitro regeneration of castor bean (ricinus communis, L) and physic nut (jatropha curcas, L.)

    International Nuclear Information System (INIS)

    Afful, N. T.

    2008-06-01

    Investigations were conducted on in vitro regeneration of physic nut (Jatropha curcas, 1.) and castor bean (Ricinus communis, 1.) using zygotic embryo culture, shoot tip and meristem culture as well as somatic embryogenesis. Zygotic embryos from different stages of fruit maturity cultured on Murashige and Skoog (MS) medium supplemented with benzylaminopurine (BAP), kinetin and 2-isopentyl (2iP) produced vigorous seedlings with roots. However the optimal concentration of cytokinin for seedling development depended on the type cytokinin as well as the maturity stage of the fruit. Embryos from yellow fruits of Jatropha had the highest germination (100%) on an MS medium supplemented with 0.5 mg/L kinetin or 1 mg/L BAP while in Ricinus embryos from black fruits had the highest percentage germination (97%) on an MS medium modified with I mg/L 2iP or 0.5 or I mg/L BAP. Decrease in embryo viability especially in Jatropha as the seed matured may be due to high oil content in matured (black) fruit. Oil content in both Jatropha and Ricinus increased as the fruit matured from green to black and this may have effect on germination of zygotic embryos. In vitro culture response of shoot tip or meristem was significantly influenced by the concentration of growth regulators in the culture medium as well as the plant species. In both plant species, 2iP resulted in highest percentage shoot regeneration. The optimal concentration of 2iP was 0.5 mg/L for Ricinus shoot tip and 1.5 or 2.0 mg/L for Jatropha, indicating genotypic difference between the species. However excessive callus formation and browning in Ricinus led to the loss of all the regenerants. Shoot regeneration from meristem explants was also influenced by growth regulators with 2iP again being the best. Cultures of cotyledon and leaf lobe explants on MS medium supplemented with 2, 4-D and picloram resulted in callus induction with the exception of cotyledons obtained from black fruits. However transfer of calli onto fresh

  20. Assessment of Envi-Carb™ as a passive sampler binding phase for acid herbicides without pH adjustment.

    Science.gov (United States)

    Seen, Andrew; Bizeau, Oceane; Sadler, Lachlan; Jordan, Timothy; Nichols, David

    2014-05-01

    The graphitised carbon solid phase extraction (SPE) sorbent Envi-Carb has been used to fabricate glass fibre filter- Envi-Carb "sandwich" disks for use as a passive sampler for acid herbicides. Passive sampler uptake of a suite of herbicides, including the phenoxyacetic acid herbicides 4-chloro-o-tolyloxyacetic acid (MCPA), 2,4-dichlorophenoxyacetic acid (2,4-D) and 3,6-dichloro-2-methoxybenzoic acid (Dicamba), was achieved without pH adjustment, demonstrating for the first time a suitable binding phase for passive sampling of acid herbicides at neutral pH. Passive sampling experiments with Duck River (Tasmania, Australia) water spiked at 0.5 μg L(-1) herbicide concentration over a 7 d deployment period showed that sampling rates in Duck River water decreased for seven out of eight herbicides, and in the cases of 3,6-dichloro-2-pyridinecarboxylic acid (Clopyralid) and Dicamba no accumulation of the herbicides occurred in the Envi-Carb over the deployment period. Sampling rates for 4-amino-3,5,6-trichloro-2-pyridinecarboxylic acid (Picloram), 2,4-D and MCPA decreased to approximately 30% of the sampling rates in ultrapure water, whilst sampling rates for 2-(4,6-dimethylpyrimidin-2-ylcarbamoylsulfamoyl) benzoic acid, methyl ester (Sulfometuron-methyl) and 3,5,6-Trichloro-2-pyridinyloxyacetic acid (Triclopyr) were approximately 60% of the ultrapure water sampling rate. For methyl N-(2,6-dimethylphenyl)-N-(methoxyacetyl)-D-alaninate (Metalaxyl-M) there was little variation in sampling rate between passive sampling experiments in ultrapure water and Duck River water. SPE experiments undertaken with Envi-Carb disks using ultrapure water and filtered and unfiltered Duck River water showed that not only is adsorption onto particulate matter in Duck River water responsible for a reduction in herbicide sampling rate, but interactions of herbicides with dissolved or colloidal matter (matter able to pass through a 0.2 μm membrane filter) also reduces the herbicide sampling

  1. The mortality and cancer experience of New Zealand Vietnam war veterans: a cohort study.

    Science.gov (United States)

    McBride, David; Cox, Brian; Broughton, John; Tong, Darryl

    2013-09-03

    The aim was to observe the patterns of mortality and cancer incidence in New Zealand Vietnam veterans. The objectives were to assess whether the patterns of disease observed were consistent with those associated with military service in Vietnam, and similar to the patterns identified in other groups of Vietnam veterans. A historical cohort study. Veterans, identified from service records, with Vietnam service between 1964 and 1972. Of the 3322 survivors of Vietnam service, we followed up 2783 (84%). Standardised mortality and incidence ratios (SMRs and SIRs, respectively) were calculated based on the number of deaths and cancer registrations observed, those expected being based on New Zealand national rates. All cause mortality was significantly reduced (SMR 0.85, 95% CI 0.77 to 0.94) and cancer incidence non-significantly increased (SIR 1.06, 95% CI 0.97 to 1.16). The risk of mortality from cancers of the head and neck (SMR 2.20, 95% CI 1.09 to 3.93); oral cavity pharynx and larynx (SMR 2.13, 95% CI 1.06 to 3.81) and the incidence of chronic lymphatic leukaemia (CLL) (SIR 1.91, 95% CI 1.04 to 3.20) were, however, significantly increased. Other lymphohaematopoietic disorders, specifically multiple myeloma and Hodgkin disease, showed non-significant mortality excesses, reflected by a similar increase in incidence. Service in the Vietnam war was associated with defoliant herbicide exposure, including 2,4,5-trichlorophenoxyacetic acid, 2,4-dichlorophenoxyacetic acid, picloram and cacodylic acid. Subsequent reviews of mechanistic, animal and epidemiological evidence led to certain conditions being deemed compensable. The pattern of mortality and cancer incidence is not at odds with the list of compensable conditions and consistent with that found in Australian veterans serving in the same area of Vietnam, but also consistent with smoking and the healthy soldier effect. In common with the Australian experience, this is the only veterans group to show a significant

  2. Efectividad de métodos de control de malezas en la producción de forraje del pasto Pangola (Digitaria decumbens Stent.

    Directory of Open Access Journals (Sweden)

    Valent\\u00EDn Alberto Esqueda-Esquivel

    2007-01-01

    Full Text Available Efectividad de métodos de con trol de ma le zas en la producción de forraje del pasto Pangola (Digitaria decumbens Stent. En el periodo de agosto de 1998 a agosto de 1999 se condujo un experimento en Emilio Carranza, municipio de Ve ga de Alatorre, Ve racruz, México, con el objeto de determinar el efec to de tra ta mien tos de con trol quí mi co y ma nual de ma le zas en la pro duc ción de fo rraje de zacate Pangola y en la den si dad de po bla ción de ma le zas presentes al inicio del siguiente ciclo de lluvias. Se utilizó el diseño experimental de blo ques completos al azar con cua tro re pe ti cio nes. Los tra tamien tos evaluados fueron: 1. Mezcla for mulada de picloram + 2,4-D (64 + 240 g/100 l agua 2. Mez cla for mu la da de pi cloram + flu ro xi pir (40 + 40 g/100 l agua 3. Con trol ma nual mediante chapeo con machete y 4. Testigo enhierbado. Las parcelas experimentales tuvieron 30 m de longitud y 10 m de anchura. Los tra ta mien tos 1, 2 y 3 se apli ca ron el 17 de agos to de 1998, cuan do la zar za de lo ma (Mimosa albida, que fue la es pe cie de ma le za do mi nan te te nía en tre 40 y 60 cm de al tu ra y la cobertura promedio de malezas del lote experimental, era de 57,9%. Se eva luó la co ber tu ra de ma le zas y pas to y el control de ma le zas a los 29, 60, 80, 114 y 154 días des pués de la aplicación de los tratamientos (DDA. También se determinó la producción de forraje de za ca te Pan go la a los 45, 80, 143 y 178 DDA. Con pi clo ram + flu ro xi pir y pi clo ram + 2,4-D, se controló más eficientemente a M. albida y el com ple jo de ma le zas her bá ceas que con el cha peo y se ob tu vo una produc ción significativamente mayor de ma teria seca de pas to. Ambos tratamientos herbicidas presentaron menor densidad de po bla ción de ma le zas en el si guien te ci clo de llu vias que el tratamiento con chapeo.

  3. Somatic embryogenesis and embryo culture coupled with gamma irradiation for generating avocado (Persea americana Miller) mutants in the Philippines

    Energy Technology Data Exchange (ETDEWEB)

    Avenido, R. A. [Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines Los Baños (Philippines); Crop Science Cluster, College of Agriculture, University of the Philippines Los Baños (Philippines); Galvez, H. F.; Dimaculangan, J. G.; Welgas, J. N.; Frankie, R. B.; Damasco, O. P. [Crop Science Cluster, College of Agriculture, University of the Philippines Los Baños (Philippines)

    2009-05-15

    Plant regeneration through somatic embryogenesis from immature zygotic embryos and embryo cultures from mature fruits were achieved in select avocado accession ‘Semil’ and other seedling trees in the Philippines. Embryogenic cultures were induced from immature zygotic embryos of eight (8) avocado genotypes using either SE1 medium (MS + 30 g/l sucrose + 5 mg/l 2, 4-D + 0.5 mg/l BAP) or SE2 medium (MS + 30 g/l sucrose + 0.1 mg/l picloram). Embryogenic cultures of 2 genotypes namely ‘Semil’ and ‘Mainit’ developed into somatic embryos after repeated subcultures in SE2, SE3 (MS + 30 g/l sucrose + 0.1 mg/l TDZ + 0.5 mg/l GA{sub 3}) and SE4 (MS + 30 g/l sucrose + 2 mg/l BAP + 1 mg/l IBA) media. Plant/shoot regeneration from ‘Semil’ somatic embryos was recorded in 3 trials at 16.3, 23.0 and 20.7%, and was affected by culture age, light treatment and media used. R4 regeneration medium (B5 macro salts + MS minor salts and vitamins + 60 g/l sucrose + 400 g/l glu + 2 mg/l BAP + 4.5 g/l Phytagel was found to be the best. Gamma irradiation (10 to 30 Gy) of embryogenic cultures of ‘Semil’ resulted in reduced proliferation and formation of cotyledonary stage somatic embryos. However, shoot regeneration from somatic embryos from gamma-irradiated cultures was comparable or even higher (17.8 to 26.9%) as compared to the control (18.3%). Over 200 somatic embryo-derived putative variant/mutant lines from tissue culture and gamma irradiation experiments are being maintained as shoot cultures. Due to slow growth and other related problems, micrografting and in vitro rooting were used to rescue and ensure the greenhouse establishment of putative mutant shoots, and fast-track mutant confirmation by genetic analysis. Preliminary genetic analyses by SSR revealed that (a) the 3 asexually propagated ‘Semil’ mother trees are genetically similar, and (b) mutations marked by the generation of a new allele (band) at the SSR locus was evident among the somatic embryo

  4. Occurrence of Pesticides in Ground Water of Wyoming, 1995-2006

    Science.gov (United States)

    Bartos, Timothy T.; Eddy-Miller, Cheryl A.; Hallberg, Laura L.

    2009-01-01

    . Considering only detections using the CAL, triazine pesticides were detected much more frequently than all other pesticide classes, and the number of different pesticides classified as triazines was the largest of all classes. More pesticides were detected at concentrations greater than the CSALs in water from wells sampled in the fall (28 different pesticides) than in the spring (21 different pesticides). Many pesticides were detected infrequently as nearly one-half of pesticides detected in the fall and spring at concentrations greater than the CSALs were detected only in one well. Using the CSALs for pesticides analyzed for in 11 or more wells, only five pesticides (atrazine, prometon, tebuthiuron, picloram, and 3,4-dichloroaniline, listed in order of decreasing detection frequency) were each detected in water from more than 5 percent of sampled wells. Atrazine was the pesticide detected most frequently at concentrations greater than the CSAL. Concentrations of detected pesticides generally were small (less than 1 microgram per liter), although many infrequent detections at larger concentrations were noted. All detected pesticide concentrations were smaller than U.S. Environmental Protection Agency (USEPA) drinking-water standards or applicable health advisories. Most concentrations were at least an order of magnitude smaller; however, many pesticides did not have standards or advisories. The largest percentage of pesticide detections and the largest number of different pesticides detected were in samples from wells located in the Bighorn Basin and High Plains/ Casper Arch geographic areas of north-central and southeastern Wyoming. Prometon was the only pesticide detected in all eight geographic areas of the State. Pesticides were detected much more frequently in samples from wells located in predominantly urban areas than in samples from wells located in predominantly agricultural or mixed areas. Pesticides were detected distinctly less often in sa