Arbuscular mycorrhizal fungi activity in the rhizosphere of tree seedlings subjected to residual herbicides / Atividade de fungos micorrízicos arbusculares na rizosfera de mudas de árvores submetidas a herbicidas residuais

Trees occurring on the margins of agricultural areas can mitigate damage from residual herbicides. Rhizospheric microbial activity associated with trees is one of the main remedial capacity indicators. The objective of this study was to evaluate the rhizospheric microbiological activity in tree species subjected to the herbicides atrazine and sulfentrazone via the rhizosphere. The experiment was designed in four blocks and a 6 × 3 factorial scheme. The first factor consisted of six tree species from Brazil and the second of atrazine, sulfentrazone, and water solutions. Four herbicide applications were performed via irrigation. The total dry mass of the plants, mycorrhizal colonization, number of spores, basal respiration of the rhizospheric soil, and survival rate of bioindicator plants after phytoremediation were determined. Trichilia hirta had higher biomass when treated with atrazine and sulfentrazone. Herbicides decreased the microbial activity in Triplaris americana and did not affect the microbiological indicators of Myrsine gardneriana, Schizolobium parahyba, and Toona ciliata. Fewer bioindicator plants survived in soil with Triplaris americana and sulfentrazone. Microbiological indicators were influenced in different ways between species by the presence of herbicides in the rhizosphere.

As árvores que ocorrem nas margens das áreas agrícolas podem mitigar os danos dos herbicidas residuais. A atividade microbiana rizosférica associada às árvores é um dos principais indicadores de capacidade corretiva. O objetivo deste trabalho foi avaliar a atividade microbiológica rizosférica em espécies arbóreas submetidas aos herbicidas atrazina e sulfentrazone via rizosfera. O experimento foi estruturado em quatro blocos e esquema fatorial 6 × 3. O primeiro fator consistiu em seis espécies de árvores do Brasil e o segundo em soluções de atrazine, sulfentrazone e água. Quatro aplicações de herbicidas foram realizadas via irrigação. Foram determinados a massa seca total das plantas, colonização micorrízica, número de esporos, respiração basal do solo rizosférico e taxa de sobrevivência de plantas bioindicadoras após fitorremediação. Trichilia hirta apresentou maior biomassa quando tratada com atrazina e sulfentrazone. Os herbicidas diminuíram a atividade microbiana em Triplaris americana e não afetaram os indicadores microbiológicos de Myrsine gardneriana, Schizolobium parahyba e Toona ciliata. Menos plantas bioindicadoras sobreviveram no solo com Triplaris americana e sulfentrazone. Os indicadores microbiológicos foram influenciados de formas distintas entre as espécies pela presença dos herbicidas na rizosfera.

Normalized difference vegetation index for desiccation evaluation with glyphosate + 2, 4-D in magnetized spray solution / Índice de vegetação por diferença normalizada para avaliação de dessecação com glyphosate + 2, 4-D em calda magnetizada

Water magnetization and geoprocessing are increasingly utilized tools in weed management. Our objective was to study the influence of water magnetization on herbicide efficiency and to verify whether there is a relationship between control scores and the normalized difference vegetation index (NDVI). In the laboratory experiment, water was subjected to magnetization and evaluated with respect to four characteristics. In the field experiment, plots of Brachiaria grass were subjected to treatments in a factorial scheme (6 × 2 + 1). Six herbicidal factors (doses of glyphosate and glyphosate + 2,4-D) and the magnetization or absence of magnetization of the spray solution were evaluated and compared against the control treatment (without spraying). Weed control assessments were carried out six times. Images were obtained using an embedded multispectral camera to determine the NDVI values. Data related to water characteristics were analyzed using the t test. Weed control and NDVI data were subjected to analysis of variance and are presented in regression graphs. Dispersion analysis of NDVI data was performed according to the control scores. The magnetization process decreased the pH of the water and increased the surface tension, but it did not influence the control scores or the NDVI. As the glyphosate dose was increased, the control scores were higher and the NDVI values were lower. Magnetized water did not affect the biological efficiency of the herbicides, and there was a strong correlation between the control scores and the NDVI values.

A magnetização da água e o geoprocessamento são ferramentas cada vez mais utilizadas no manejo de ervas daninhas. Nosso objetivo foi estudar a influência da magnetização da água na eficiência do herbicida e verificar se existe uma relação entre os escores de controle e o índice de vegetação por diferença normalizada (NDVI). No experimento de laboratório, a água foi submetida à magnetização e avaliada em relação a quatro características. No experimento de campo, parcelas de capim-braquiária foram submetidas a tratamentos em esquema fatorial (6 × 2 + 1). Seis fatores herbicidas (doses de glyphosate e glyphosate + 2,4-D) e a magnetização ou ausência de magnetização da calda foram avaliados e comparados com o tratamento controle (sem pulverização). Avaliações de controle de plantas daninhas foram realizadas seis vezes. As imagens foram obtidas usando uma câmera multiespectral incorporada para determinar os valores de NDVI. Os dados relacionados às características da água foram analisados por meio do teste t. O controle de plantas daninhas e os dados de NDVI foram submetidos à análise de variância e são apresentados em gráficos de regressão. A análise de dispersão dos dados NDVI foi realizada de acordo com os escores de controle. O processo de magnetização diminuiu o pH da água e aumentou a tensão superficial, mas não influenciou nos escores de controle ou no NDVI. Conforme a dose de glyphosate foi aumentada, os escores de controle foram maiores e os valores de NDVI foram menores. A água magnetizada não afetou a eficiência biológica dos herbicidas, e houve uma forte correlação entre os escores de controle e os valores de NDVI.

Perinatal exposure to an aromatase inhibitor glyphosate-base herbicide reduced male and female social behavior in juvenile age and the sexual behavior at adult female rats / Exposição perinatal ao inibidor da aromatase a base de glifosato reduz o comportamento social de machos e fêmeas e o comportamento sexual de ratas

Objectives: The herbicide glyphosate, a pesticide used in agriculture to control weeds, both in food crops and in other agricultural areas, has been identified as an endocrine modulator through the inhibition of aromatase activity and the activation of estrogen receptors. The present study examined the effects of a glyphosate-based herbicide (Roundup® (GLY-BH) on sexual dimorphism of rats after perinatal exposure to low and high GLY-BH in males and females offspring. Methods: Two groups of pregnant rats were treated with two doses of GLY-BH (50 or 150 mg/kg) from day 15 of gestation (GD15) to postnatal day 7 (PND7). Play fighting behavior was observed at the juvenile stage and during social and sexual behaviors in adulthood. Results: Perinatal GLY-BH exposure reduced male and female body weight at 28, 75, and 90 days of age. The play fighting behavior was decreased in both sexes, but female rats were more affected. The sexual behaviors were reduced only in females. Conclusions: Perinatal exposure to both doses of GLY-BH promoted sexually dimorphic effects in both juvenile and adulthood stages. These effects were attributed to the inhibition of aromatase activity induced by exposure to GLY-BH in the perinatal period.(AU)

Objetivos: O glifosato é um herbicida não seletivo, usado em muitas culturas alimentares e não alimentares e em áreas não agrícolas, sendo que os produtos a base de glifosato atuam como moduladores das funções endócrinas por meio da inibição da atividade da aromatase e da ativação de receptores de estrógeno. O presente estudo avaliou os efeitos do herbicida Roundup® (GLY-BH) à base de glifosato, em comportamentos sexualmente dimórficos de ratos após exposição perinatal a doses baixas e altas de GLY-BH no período perinatal. Métodos: Ratas prenhas foram tratadas com 50 ou 150 mg/kg de GLY-BH do 15º dia de gestação (GD15) ao 7º dia de lactação (LD7). O comportamento de luta/brincar foi observado na fase juvenil e os comportamentos social e sexual na idade adulta. Resultados: a exposição perinatal a GLY-BH reduziu o peso corporal de machos e fêmeas aos 28, 75 e 90 dias de idade. O comportamento de luta/brincar diminuiu em ambos os sexos, sendo as ratas foram as mais afetadas. O comportamento sexual foi reduzido apenas nas fêmeas. Conclusões: A exposição perinatal a ambas as doses do GLY- BH promoveu tanto na idade juvenil como na idade adulta, efeitos sexualmente dimórficos. Esses efeitos foram atribuídos à inibição da atividade da aromatase induzida exposição perinatal ao GLY-BH.(AU)

Selectivity of herbicides applied to Brazilian tree species at post-emergence

The presence of weeds in silvicultural systems has been considered one of the main obstacles to the success of projects designed to recover degraded areas. The aim of this study was to evaluate the selectivity of herbicides applied at post-emergence in the initial growth of seedlings of capixingui (Croton floribundus), açoita-cavalo (Luehea divaricata), and guaritá (Astronium graveolens), in the municipalities of Jaboticabal and Junqueirópolis, state of São Paulo. The experimental design was completely randomized, with four replications, and the treatments consisted of herbicides (g a.i.·ha-1) clethodim + phenoxaprop-p-ethyl (50 + 50), sethoxydim (184), quizalofop-p-ethyl (75), nicosulfuron (50), fluazifop-p-butyl (125), fomesafen (225), haloxyfop-methyl (48), bentazon (720), chlorimuron-ethyl (15), in addition to control without herbicide. The characteristics analyzed were: plant height increase and visual phytointoxication at 7, 14, 21, 28, 35, and 42 days after herbicide application. At the end of the experiment, the shoots of the plants were removed to assess shoot dry matter. The herbicides clethodim + fenoxaprop-p-ethyl, fluazifop-p-butyl, and quizalofop-p-ethyl showed selective potential for the species capixingui, açoita-cavalo, and guaritá. The herbicide chlorimuron-ethyl caused mild intoxication symptoms when applied to seedlings of capixingui and açoita-cavalo; also, it was not selective for the guaritá species grown in Jaboticabal. All species showed selectivity to the herbicides sethoxydim, fomesafen, haloxyfop-methyl, and nicosulfuron, as their growth and initial development were not influenced. The herbicide bentazon caused high percentages of injury to açoita-cavalo plants in both cultivation places, but it did not influence the growth and development of the species.

Mixture compatibility of Anticarsia gemmatalis nucleopolyhedrovirus (AgMNPV) with pesticides used in soybean / Compatibilidade da mistura de nucleopoliedrovírus de Anticarsia gemmatalis baculovírus (AgMNPV) com agrotóxicos utilizados na soja

Anticarsia gemmatalis (Hübner: 1818) (Lepidoptera: Erebidae) is one of the main pests that affect soybean crops, causing defoliation. In the vegetative stages, defoliation occurs together with weeds, and in the reproductive stages with pathogens. In this sense, to maintain plant health, it is necessary to carry out the combined use of pesticides. Thus, this research determined the compatibility of the entomopathogenic virus AgMNPV with the main herbicides and fungicides used in soy at different times of the mixture. The artificial diet was immersed in the solutions of the pesticides and their mixtures and supplied to A. gemmatalis caterpillars, immediately and after one and two hours of mixing. The evaluation was performed by quantifying the number of dead caterpillars by mixing the AgMNPV virus with herbicides and fungicides, even after two hours of mixing if compatible. The observed scenarios showed a compatibility of the virus with the herbicides and fungicides, with mortality rates between 70 to 99% for A. gemmatalis.

Anticarsia gemmatalis (Hübner: 1818) (Lepidoptera: Erebidae) é uma das principais pragas que acometem a cultura da soja, causando desfolha. Nos estágios vegetativos a desfolha ocorre juntamente com ervas daninhas, e no reprodutivo com patógenos. Nesse sentido, para manter a fitossanidade, é necessário realizar a utilização combinada de pesticidas. Assim, o objetivo do presente trabalho foi determinar a compatibilidade do vírus entomopatogênico AgMNPV com os principais herbicidas e fungicidas utilizados na soja em diferentes tempos de mistura. A dieta artificial foi imersa nas soluções dos pesticidas e suas misturas e fornecida às lagartas de A. gemmatalis, imediatamente e após uma e duas horas de mistura. A avaliação foi realizada quantificando o número de lagartas mortas. A mistura do vírus AgMNPV com herbicidas e fungicidas, mesmo após duas horas de mistura se mostrou compatível. Os cenários observados mostram a compatibilidade do vírus com os herbicidas e fungicidas, com percentuais de mortalidade entre 70 a 99% para A. gemmatalis.

Use of the imazapic herbicide applied alone or tank mix with imazapyr as growth regulator of lawns

Successive mowing are the major maintenance costs of lawns. Thus, both the expenditure with mowing and the visual and physiological aspect of the lawn have led to the search for alternatives to mechanical management. Thus, this work aimed to study the effects of different rates of imazapic herbicide applied alone or combined with imazapyr as a growth regulator of Bahiagrass (Paspalum notatum) and St. Augustine grass (Stenotaphrum secundatum). The experimental design was a randomized block with four replicates, and the treatments consisted of six rates of imazapic herbicide (35; 70; 105; 140; 175 and 210 g a.i. ha-1) for both species, three rates of imazapic + imazapyr in tank mix (15.57 + 5.25; 23.625 + 7.875; 32.5 + 10.5 g a.i. ha-1) for Bahiagrass and four rates of imazapic + imazapyr mixture (7.875 + 2.625; 15.57 + 5.25; 23.625 + 7.875; 32.5 + 10.5 g a.i. ha-1) for St. Augustine grass. The effect of the treatments was evaluated by observing visible injury symptoms, canopy height, height and number of inflorescences and total dry matter of clippings. Applications of imazapic alone or combined with imazapyr were effective in reducing plant height, number and height of inflorescences and total amount of dry matter of clippings produced by Bahiagrass plants. Imazapic provided satisfactory control of St. Augustine growth, but its utilization caused an increase in the number of inflorescences present in the lawns.

Efecto de la n-acetilcisteina inhalada en el desarrollo de fibrosis pulmonar de ratas intoxicadas con paraquat / Effect of n-acetylcisteine inhaled in the development of pulmonary fibrosis of intoxicated rats with paraquat

El Paraquat (PQ) es un herbicida de contacto bipiridilico ampliamente utilizado en agricultura. La intoxicación en humanos por este agente ocasiona fibrosis pulmonar. Evaluamos los cambios histológicos pulmonares de ratas intoxicadas con PQ y tratadas con N-aceticisteina (NAC) administrada vía inhalatoria. Realizamos un estudio experimental descriptivo con 25 ratas adultas, machos cepa Wistar, divididas en cinco grupos. Al grupo I no se les administro ni PQ ni NAC. Grupo II, recibió NAC inhalada a 15mg/kg diaria c/12 horas. Grupo III, PQ vía oral (VO) 15mg/kg. Grupo IV, PQ a 15mg/kg, por VO y a la hora NAC 150mg/kg. Grupo V, PQ a 15mg/kg, por VO y a las seis horas NAC dosis de 150mg/kg. Los pulmones fueron extraídos y se evaluaron mediante cortes histológicos. Resultados: Los grupos I y II (supervivencia del 100%, n=10) no desarrollaron sintomatología de intoxicación. Grupos III, IV y V predominaron síntomas respiratorios, diversos grados de edema pulmonar, enfisema, congestión vascular y hemorragia intra-alveolar focal. La eficacia de la NAC sobre la intoxicación por PQ en términos de sobrevivencia al primer día, fue del 100% y al segundo día, fue del 80% (p= 0,005; prueba Chi-cuadrado). El PQ indujo un proceso inflamatorio (agudo-crónico) por infiltrado de segmentados neutrófilos y linfocitos, lo cual fue revertido parcialmente por la administración inhalada de NAC. Conclusión: Los cambios histopatológicos observados a nivel pulmonar fueron aminorados por el tratamiento con NAC, lo que sugiere un posible efecto protector de este fármaco sobre el daño oxidativo inducido por el herbicida

Paraquat (PQ) is a bipyridyl contact herbicide widely used in agriculture. Intoxication in humans by this agent causes pulmonary fibrosis. We evaluated pulmonary histological changes of rats intoxicated with PQ and treated with N-acetycysteine (NAC) administered via inhalation. We conducted a descriptive experimental study with 25 adult rats, male Wistar strain, divided into five groups. Group I was not administered PQ or NAC. Group II, received NAC inhaled at 15mg/kg daily c/12 hours. Group III, PQ orally (VO) 15mg/ kg. Group IV, PQ at 15mg/kg, by VO and at hour NAC 150mg/ kg. Group V, PQ at 15mg/kg, by VO and at six hours NAC dose of 150mg/kg. The lungs were extracted and evaluated by histological sections. Results: Groups I and II (100% survival, n=10) did not develop intoxication symptoms. Groups III, IV and V predominantly respiratory symptoms, various degrees of pulmonary edema, emphysema, vascular congestion and focal intra-alveolar hemorrhage. The efficacy of NAC on PQ poisoning in terms of survival on the first day was 100% and on the second day it was 80% (p = 0.005, Chi-square test). The PQ induced an inflammatory process (acute-chronic) by infiltration of segmented neutrophils and lymphocytes, which was partially reversed by the inhaled administration of NAC. Conclusion: The histopathological changes observed at the pulmonary level were reduced by the treatment with NAC, which suggests a possible protective effect of this drug on the oxidative damage induced by the herbicide.

Las malezas, plantas incomprendidas / Weeds, misunderstood plants

Etiquetadas por la agricultura moderna como pestes, las plantas de origen espontáneo, en los campos de cultivos son conocidas como malezas. Una denominación que denota una influencia negativa derivada de la conceptualización del ser humano sobre algunas especies vegetales. Nombrar maleza a una planta es, a juicio de los autores, un criterio sesgado. Un estado del arte poco robusto, sobre las bondades de una especie la condena a ser clasificada como una especie no deseada. En la agricultura moderna lo no deseado es eliminado. Las malezas han sido condenadas desde el inicio mismo de las labores agrícolas. No se les ha dado la oportunidad de mostrar que también pueden proveer bondades a los sistemas de producción. La erradicación de malezas no ha funcionado de forma permanente en los campos de cultivo. Las especies espontaneas se han abierto paso en la agricultura moderna. Han superado adversidades en toda la historia de la agricultura. Siempre presentes en los campos de cultivo las malezas nos desafían a convivir con ellas desde un enfoque diferente. Se han dado ya pasos importantes en la investigación del uso alternativo de estas especies. La investigación que implique la convivencia en detrimento de la eliminación es necesaria. Es momento de dejar de odiar a las malezas e iniciar a comprenderlas como parte importante del ecosistema agrícola.

Designated by modern agriculture as pests, the spontaneous plants, in the croplands are known as weeds. A denomination that denotes a negative influence on the conceptualization of the human being over some plant species. Naming a plant as weed is according to the authors a biased criterion. A weak state of art, on the kindness of a species condemns it to be classified as an unwanted species. In modern agriculture the unwanted is eliminated. Weeds have been doomed since the beginning of agriculture. They have not been given the opportunity to show that they can also provide benefits to production systems. The eradication of weeds has not been permanently effective in the fields. The spontaneous species have made their way in modern agriculture. They have overcome adversity throughout the history of agriculture. Always present in the fields, weeds challenge us to live with them from a different perspective. Important steps have already been taken in the investigation of the alternative use of these species. Research that implies coexistence to the detriment of elimination is necessary. It is time to stop hating weeds and begin to understand them as an important part of the agricultural ecosystem.

Does the sequence of addition of herbicide and adjuvants to the spray solution influence sicklepod control? / A sequência de adição de herbicida e adjuvantes à calda influencia no controle de fedegoso?

The use of adjuvants associated with herbicides aims at improving the performance of application and the consequent increase in the biological effect of the treatment. However, the sequence of product added to the sprayer tank can influence the phytosanitary spray solution. Thus, this study aimed to evaluate the control of Senna obtusifolia as a function of the sequence of addition of the herbicide aminopyralid + fluroxypyr and adjuvants in the preparation of spray solution. Two herbicide doses (1 and 2 L c.p. ha-1) associated with the adjuvants mineral oil (MO), silicone polyether copolymer (SIL), and a mixture of phosphatidylcholine and propionic acid (LEC), all in the proportion of 0.3% v v-1, with alternate addition to the spray solution to evaluate the effects of the preparation sequence. The spray solution volume considered was 150 L ha-1. Evaluations of spray solution stability were performed from the visual evaluation of homogeneity, electrical conductivity, and pH. The effect of treatment on S. obtusifolia control was measured using a scoring scale and dry matter. Correlation coefficients between the evaluations were also determined. No difference of the preparation sequence of spray solution was observed for stability, pH, and electrical conductivity, but an influence was observed on S. obtusifolia control, without changing dry matter accumulation. The treatment with the adjuvant LEC previously added to the herbicide provided a higher control rate at the highest dose, while the adjuvant SIL had the opposite effect.(AU)

O uso de adjuvantes associados a herbicidas visa melhorar o desempenho da aplicação e o consequente aumento do efeito biológico do tratamento. Porém, a ordem de adição dos produtos ao tanque do pulverizador pode trazer importantes influências à calda fitossanitária. Assim, o objetivo desta pesquisa foi avaliar o controle de Senna obtusifolia em função da sequência de adição do herbicida aminopiralide + fluroxipir e de adjuvantes no preparo das caldas. Foram utilizadas duas dosagens de herbicida (1 e 2 L p.c. ha-1), associadas aos adjuvantes óleo mineral (OM); copolímero de poliéter e silicone (SIL); mistura de fosfatidicolina e ácido propiônico (LEC), todos na proporção de 0,3% v v-1, com adição alternada à calda para avaliar os efeitos da sequência de preparo. O volume de calda considerado foi de 150 L ha-1. Foram realizadas avaliações da estabilidade da calda a partir da avaliação visual de homogeneidade, condutividade elétrica e pH. O efeito do tratamento no controle de S. obtusifolia foi mensurado por meio de uma escala de pontuação e pela massa seca. Também foram determinados os coeficientes de correlação entre as avaliações. Verificou-se que não houve diferença da sequência de preparo da calda para a estabilidade, o pH e a condutividade elétrica. Porém, a sequência de preparo influenciou o controle inicial de S. obtusifolia, sem efeito sobre a massa seca. O tratamento com o adjuvante LEC adicionado ao herbicida proporcionou maior taxa de controle na maior dosagem, enquanto o adjuvante de SIL teve o efeito oposto.(AU)

Interação entre nematicidas e herbicidas pré-emergentes no desenvolvimento inicial da cultura da cana-de-açúcar / Interaction between nematicides and pre-emergent herbicide in the initial development of sugar cane / Interacción entre nematicidas y herbicidas pre emergentes en el desarrollo inicial de la cultura de caña de azúcar

O objetivo do trabalho foi avaliar a interação do herbicida tebuthiuron (Combine® 500 SC), com nematicidas carbofuram (Furadan® 350 SC) e benfuracarbe (Pottente®), aplicados no plantio da cultura da cana-de-açúcar (RB 867515). O experimento foi conduzido em casa de vegetação da Universidade Paranaense, em Umuarama ­ PR, no período de abril a agosto de 2014. Foi instalado em vasos com capacidade para 4,5 L, contendo uma planta por vaso, em delineamento inteiramente casualizado, com seis tratamentos e quatro repetições, sendo os tratamentos testemunha (T1), sem aplicação de produtos; aplicação isolada de carbofuran (T2); aplicação isolada de benfuracarbe (T3); aplicação isolada de tebuthiuron (T4); aplicação combinada de carbofuran e tebuthiuron (T5) e aplicação combinada de benfuracarbe e tebuthiuron (T6). O experimento foi submetido a duas avaliações, 45 e 90 dias após o plantio (DAP) sendo que na primeira, as variáveis avaliadas foram altura da parte aérea, número de folhas e número de plantas daninhas por vaso, e, na segunda, altura da parte aérea; número de folhas; número de plantas daninhas; massa fresca e seca da parte aérea; massa fresca do sistema radicular; população final total de nematoides por vaso, calculada pelo somatório de nematoides nas raízes e solo. Quanto ao número de folhas, o tratamento T4 demonstrou fitotoxicidade aos 45 DAP. Os tratamentos T3, T5 e T6 apresentaram as maiores massa fresca e seca da parte área da cana, demonstraram ausência de interação antagônica entre as combinações do herbicida com os nematicidas aos 90 DAP. Os tratamentos T3 e T5 foram eficientes no controle populacional de P. zeae.(AU)

The aim of the study was to evaluate the interaction of the herbicide tebuthiuron (Combine® SC 500), with the following nematicides: carbofuran (350 Furadan® SC) and benfuracarb (Pottente®) applied during the planting of cane sugar (RB 867515). The experiment was conducted in a greenhouse at Universidade Paranaense in Umuarama - PR, from April to August 2014. The crop was started in 4.5-L vases containing one plant per vase, in a completely randomized design with six treatments and four replications, namely control treatments (T1), with no application of products; isolated application of carbofuran (T2); isolated application of benfuracarb (T3); isolated application of tebuthiuron (T4); combined application of carbofuran and tebuthiuron (T5) and combined application of benfuracarb and tebuthiuron (T6). The experiment was submitted to two assessments, at 45 and 90 days after planting (DAP). On the first assessment, the variables analyzed were shoot height, number of leaves and number of weeds per vase. The second assessment analyzed shoot height; number of leaves; number of weeds; fresh and dry weight of shoot; fresh weight of the root system; total final population of nematodes per vase, calculated by the sum of nematodes in the roots and soil. Regarding the number of leaves, the T4 treatment showed phytotoxicity at 45 DAP. The T3, T5 and T6 treatments had the highest fresh and dry weight of the aerial part of the sugar cane; with absence of antagonistic interaction between the combinations of herbicide and nematicides at 90 DAP. The T3 and T5 treatments were effective in controlling the population of P. zeae.(AU)

El objetivo del estudio ha sido evaluar la interacción del herbicida tebuthiuron (Combine® 500 SC), con nematicidas carbofuram (Furadan® 350 SC) y benfuracarbe (Pottente®), aplicados en plantío de caña de azúcar (RB 867515). El experimento ha sido dirigido en el área de vegetación de la Universidad Paranaense, en Umuarama - PR, en el período de abril a agosto de 2014. Se ha instalado en floreros con capacidad para 4,5 L, conteniendo una planta por florero, en delineamiento enteramente casualizado, con seis tratamientos y cuatro repeticiones, siendo los tratamientos testigo (T1), sin aplicación de productos; aplicación aislada de carbofuran (T2); aplicación aislada de benfuracarbe (T3); aplicación aislada de tebuthiuron (T4); aplicación combinada de carbofuran y tebuthiuron (T5) y aplicación combinada de benfuracarbe y tebuthiuron (T6). El experimento ha sido sometido a dos evaluaciones, 45 y 90 días después del plantío (DAP) siendo que en la primera, las variables evaluadas fue la altura de la parte aérea, número de hojas y el número de plantas dañinas por florero, y, en la segunda, altura de la parte aérea, número de hojas, número de plantas dañinas; masa fresca y seca de la parte aérea; masa fresca del sistema radicular; población final total de nematodos por florero, calculado por la suma de nematodos en las raíces y suelo. Cuanto al número de hojas, el tratamiento T4 demostró citotoxicidad a los 45 DAP. Los tratamientos T3, T5 y T6 presentaron mayor masa fresca y seca en la parte aérea de la caña, demostraron ausencia de interacción antagónica entre las combinaciones de los herbicidas con los nematicidas a los 90 DAP. Los tratamientos T3 y T5 fueron eficientes en el control poblacional de P. zeae.(AU)

Efeito de diferentes herbicidas, doses e volume de calda na dessecação de milheto [Pennisetum Glaucum (L. Leek)] / Effect of different herbicides, doses and spray volume in the chemical management of pearl millet [Pennisetum Glaucum (L. Leek)]

Objetivou-se nesse trabalho avaliar a eficácia de diferentes herbicidas aplicados em pósemergência na de secação do milheto com diferentes doses e volumes de calda de aplicação. Para a dessecação do milheto foram utilizadas doses de 0, 25, 50 e 100% dos herbicidas glyphosate (1.440 g ha-1), em três formulações comerciais (Round up Original, Round up Transorb e Round up WG), paraquat + diuron (500 + 250 g ha-1) e amônio-glufosinato (800 g ha-1). Em todos os tratamentos foram utilizados dois volumes de aplicação (200 e 400 L ha-1). Manteve-se uma testemunha sem aplicação de herbicidas. Os efeitos dos tratamentos foram avaliados visualmente aos 3, 7, 14, 21 e 28 dias após aplicação. Ao final das avaliações foi determinada a massa seca das plantas. O estudo de campo foi instalado no delineamento em blocos casualizados. No final do estudo, aos 28 DAA, todos os tratamentos apresentaram controle total das plantas de milheto, independente da dose e do volume de aplicação, exceto para os tratamentos com paraquat + diuron e amônio-glufosinate na menor dose (25% da dose), nos dois volumes de aplicação, que apresentaram ainda controles considerados bons a muito bom, sendo que para esses dois herbicidas houve efeito do volume de calda, na qual o controle foi superior com o uso de volume menor.

The objective of this work was to evaluate the efficacy of different herbicides applied in post-emergence in the desiccation of pearl millet with different doses and spray volumes. For the desiccation, doses at 0, 25, 50 and 100% of the herbicide glyphosate (1,440 g ha-1) were used in 3 formulations (Original Round up, Round up Transorb and Round up WG), paraquat + diuron (500 + 250 g ha-1) and glufosinateammonium (800 g ha-1). In all treatments, 2 spray volumes (200 and 400 l ha-1) were used, and there was 1 treatment (control) without the application of herbicides. The treatment effects were evaluated visually at 3, 7, 14, 21 and 28 days after application (DAA). At the end of the evaluations, the dry mass of the plants was determined. The field trial was carried out in randomized block design. At the end of the study, at 28 DAA, all treatments presented total control of plant pearl millet, regardless of the dose and spray volume, except the treatments with paraquat + diuron and glufosinate-ammonium at the lower dose (25%), in 2 spray volumes, which nevertheless showed good and very good control, these two herbicides presenting an effect of volume, in which the control was higher with the use of smaller volume.

Effect of Glutathione Administration on Serum Levels of Reactive Oxygen Metabolites in Patients with Paraquat Intoxication: A Pilot Study

BACKGROUND/AIMS: Based on preliminary in vitro data from a previous study, we proposed that 50 mg/kg glutathione (GSH) would be adequate for suppressing reactive oxygen species in patients with acute paraquat (PQ) intoxication. METHODS: Serum levels of reactive oxygen metabolites (ROM) were measured before and after the administration of 50 mg/kg GSH to each of five patients with acute PQ intoxication. RESULTS: In one patient, extremely high pretreatment ROM levels began to decrease prior to GSH administration. However, in the remaining four cases, ROM levels did not change significantly prior to GSH administration. ROM levels decreased significantly after GSH administration in all cases. In two cases, ROM levels decreased below that observed in the general population; one of these patients died after a cardiac arrest at 3 hours after PQ ingestion, while the other represented the sole survivor of PQ intoxication observed in this study. In the survivor, ROM levels decreased during the first 8 hours of GSH treatment, and finally dropped below the mean ROM level observed in the general population. CONCLUSIONS: Treatment with 50 mg/kg GSH significantly suppressed serum ROM levels in PQ-intoxicated patients. However, this dose was not sufficient to suppress ROM levels when the PQ concentration was extremely high.

Novel s-triazine-degrading bacteria isolated from agricultural soils of central Chile for herbicide bioremediation

s-Triazine-degrading bacterial strains were isolated from long-term simazine-treated agricultural soils of central Chile. The number of culturable heterotrophic bacteria of these agricultural soils (7 x 10(6) CFU/g of dry soil) was not affected by simazine application on field. The simazine-degrading bacterial strains P51, P52 and C53 were isolated by enrichment in minimal medium using simazine as the sole nitrogen source. Resting cells of strains P51 and P52 degraded >80 percent of simazine within 48 hrs, whereas strain C53 was able to remove >60 percent of the herbicide. The atzA and atzD genes of the s-triazine upper and lower catabolic pathways were detected in strains P51 and C53, while only atzD gene was observed in strain P52. To compare the bacterial 16S rRNA gene sequence structure, ARDRA were performed using the restriction enzymes Msp1 and Hha1. ARDRA indicated that strain P52 was a different ribotype than C53 and P51 strains. For further characterization the novel isolates were identified by 16S rRNA gene sequencing. Strains C53 and P51 belong to the genus Stenotrophomonas and the strain P52 belongs to the genus Arthrobacter . s -Triazine-degrading bacterial strains isolated from contaminated soils could be used as biocatalysts for bioremediation of these herbicides.

Effect of isoproturon on male reproductive system: clinical, histological and histoenzyonological studies in rats.

Isoproturon, a nonhalogenated substituted phenylurea herbicide, was evaluated for its cumulative toxic effects on testicular histomorphology., steroid hormone biosynthesis-related enzymes, spermatogenesis and sperm cells in adult albino rats. The compound, suspended in refined groundnut oil, was administered (po) to rats for 10 weeks @ 0,200, 400 and 800 mg/kg/day for 6 days/week. Isoproturon, at 800 mg/kg dose, decreased epididymal sperm count and percentage of motile sperms and increased the percentage of morphologically abnormal sperm cells. At the same dose, diameter of seminiferous tubules was reduced, number of tubules per microscopic field was increased and the percentage of tubules with evidence of spermatogenesis decreased. However, the percentage of damaged tubules was increased with 400 and 800 mg/kg doses. Histoenzymological observations revealed dose-related reduction in the activities of glucose-6-phosphate dehydrogenase and delta 5-3 beta-hydroxy steroid dehydrogenase. Activity of 17 beta-hydroxy steroid dehydrogenase was not affected appreciably. Overall findings suggest that isoproturon, at high dose, impairs androgen biosynthetic process, affects spermatogenesis and induces maturational anomalies of sperm cells in rat.

Subacute toxicity of urea herbicide, isoproturon, in male rats.

Isoproturon, a substituted phenylurea herbicide, was evaluated for its cumulative toxic effect on growth, organ weight and histomorphology of different organs in adult male rats. The compound (200, 400 and 800 mg/kg/day for 6 days/week), suspended in refined groundnut oil, was administered to rats p.o. for 7 and 10 weeks. There were no definite signs and symptoms of toxicity in treated rats but the herbicide significantly decreased the weekly body weight of rats at 800 mg/kg dose. Isoproturon, in all the three doses, increased the weight of liver in a dose-dependent manner. At 800 mg/kg dose, isoproturon increased the weight of kidney and heart, and decreased the weight of epididymis. Histopathological alterations in the organs were dose-dependent. Salient microscopic changes induced by isoproturon were hepatocellular degenerative changes and focal necrosis in liver, glomerular and tubular degeneration in kidney and haemosiderosis in spleen. Testis showed degeneration and desquamation of cells of germinal layers. Tubular lumens of testis and epididymis exhibited reduced number of spermatids and spermatozoa, respectively, indicating retardation of spermatogenesis.