13 research outputs found
MANEJO QUÍMICO DE ESPÉCIES DE CORDA-DE-VIOLA (Ipomoea e Merremia) EM ÁREAS DE PRODUÇÃO DE CANA-DE-AÇÚCAR
Nos últimos anos verificou-se um aumento no sistema de colheita mecanizada e sem queima da cana-de-açúcar. Esse sistema modificou algumas características da colheita, uma vez que deixa sobre o solo diferentes quantidades de palha, que influem na incidência de luz no local e conseqüentemente na ocorrência e nas formas de manejo das plantas daninhas, favorecendo a infestação de espécies do gênero Ipomoea e Merremia. O crescimento de focos de cordas-de-viola e Merremias nas plantações de cana-de-açúcar é motivo de preocupação constante dos produtores brasileiros. A planta daninha diminui a produtividade nas áreas infestadas e atrapalha a colheita mecanizada. Objetivou-se com este trabalho estudar a eficácia dos herbicidas sulfentrazone, diuron + hexazinone, metribuzin e ametryn + clomazone utilizados em áreas de cana crua no controle de espécies do gênero Ipomoea e Merremia. Para isto foi realizado um levantamento das áreas com aplicação destes herbicidas e realizada avaliação visual de controle dos 70 a 90 DAA com relação à testemunha de cada talhão. Os dados foram tabulados e analisados com a utilização de histogramas e polígono de freqüência. Os resultados permitiram concluir que todos os herbicidas obtiveram controle maior ou igual a 90%. Não foram observadas áreas com problemas evidentes após aplicação, principalmente para diuron + hexazinone, cujo menor controle foi de 90%
Comparative dose-response curves between sourgrass (Digitaria insularis) resistant and susceptible biotypes to glyphosate
A utilização frequente do glyphosate em sistemas de produção da cultura do citros tem selecionado no Brasil populações resistentes de capim-amargoso (Digitaria insularis) a este herbicida, sendo importante caracterizar os níveis desta resistência para fundamentação de recomendações de medidas racionais de manejo. Sendo assim, foi conduzido um ensaio para elaboração de curvas de dose-resposta comparativa entre dois biótipos da planta daninha capim-amargoso, um resistente (R) e outro suscetível (S) ao herbicida glyphosate. O ensaio foi conduzido em casa-de-vegetação no período de fevereiro a maio de 2012, com cinco doses, do herbicida glyphosate, tendo como base a dose recomendada do herbicida, 900 g e.a. ha-1 (0,0; 450; 900; 1.800; 3.600 e 7.200 g e.a. ha-1), e a planta daninha com 3 a 4 perfilhos no momento da aplicação. Avaliou-se porcentagem de redução da biomassa seca em relação a dose 0,0 e porcentagem visual de controle, aos 14 dias após a aplicação do herbicida. O fator de resistência R/S foi de 16,66, quando baseado na redução percentual da biomassa seca, e de 20,26 quando baseado na porcentagem de controle. Sendo assim, o biótipo R tem um alto grau de resistência, maior que os já relatados na literatura, que estão em dimensões menores que 10. Alto grau de resistência pode indicar que os mecanismos de resistência ao glyphosate neste biótipo são resultantes de alteração no sítio de ação ou super expressão gênica, e não do metabolismo, como geralmente ocorre em plantas daninhas com baixos valores do fator R/S. Para determinação destes mecanismos há necessidade de novos estudos. Conclui-se também que o manejo deste biótipo deve estar fundamentado em herbicidas alternativos ao glyphosate, pois incrementos na dose de glyphosate provavelmente não são viáveis economicamente.The frequent use of glyphosate in citrus cropping systems of citrus in Brazil has selected resistant populations of sourgrass (Digitaria insularis) to this herbicide, and it is important to characterize this resistance levels for reasons of rational recommendations for management measures. Thus, an assay was conducted to elaborate comparative dose-response curves between two biotypes sourgrass weed, one resistant (R) and one susceptible (S) to glyphosate. The assay was conducted in a greenhouse from February to May 2012, with five doses of the herbicide glyphosate, based on the recommended dose of the herbicide 900 g ae ha-1 ( 0.0, 450, 900, 1,800, 3,600 and 7,200 g ae ha-1) , and the weed with 3-4 tillers at time of application. It was evaluated the percentage of the dry matter in relation to dose 0.0 of glyphosate, percentage of visual control, 14 days after herbicide application. The resistance factor R/S was 16.66, when based on dry matter and 20.26 when based on the percentage of control. Thus, the R biotype has a high degree of resistance, higher than those previously reported in the literature that are smaller than 10. High degree of resistance may indicate that the mechanisms of glyphosate resistance in this biotype are the result of changes at the site of action or super gene expression, and not to metabolism, as usually occurs in weeds with low values of R/S factor. Further studies are necessary to determine these mechanisms. It was also concluded that the management of this biotype should be based on alternative herbicides to glyphosate, because increments in the dose of glyphosate are probably not economically viable
Automatically controlled deficit irrigation of lettuce in “organic potponics”
Concerns with water crisis involve all sectors of society and irrigated agriculture remains the main water consumer. This study evaluated an agricultural production system for lettuce cultivation in greenhouse, “organic potponics”, to economize water and manure use, using a Simplified Irrigation Controller (SIC), based on soil matric potential monitoring. Five irrigation volumes were evaluated in pots with 4.8 L, fertilized with 200 g of vermicompost. One of the volumes was controlled with the SIC. The other volumes represented 130, 80, 60 and 33 % of that controlled by the SIC and all treatments received water at the same time. Shoot fresh weight, head diameter and stomatal conductance (gs) increased linearly with irrigation volumes. For shoot dry weight, number of leaves and water use efficiency (WUE), the regression was quadratic with maximum values at 126, 114 and 83 %, respectively. Leaf relative water content did not show variation among treatments and changes in some fluorescence parameters (Reo/RC, Sm, N and φR0) were much more remarkable to drought compared with the FV/ FM ratio, one of the most commonly used stress indicators. The data indicated a tradeoff between WUE and plant growth thus the economic values of water and lettuce should be taken into account to indicate the best SIC irrigation volume. Organic potponics is promising and should be further improved to save on water, labor and fertilizer use
Aspects of the biology of Digitaria insularis resistant to glyphosate
A utilização frequente de glyphosate em sistemas de produção envolvendo as culturas de soja e milho, resistentes ao glyphosate, tem selecionado populações resistentes de plantas daninhas a este herbicida, sendo comum no Brasil a ocorrência de populações resistentes de capim amargoso (Digitaria insularis). Para manejo racional destas populações, há necessidade de medidas alternativas envolvendo herbicidas e práticas culturais, as quais somente podem ser empregadas adequadamente com o conhecimento da biologia da planta daninha, porém atualmente pouco se sabe sobre a biologia do capim amargoso. Portanto, este trabalho teve como objetivo obter informações básicas da biologia das populações de capim-amargoso suscetíveis e resistentes ao herbicida glyphosate. Para isso, foram conduzidos três ensaios no Departamento de produção Vegetal da ESALQ/USP, em Piracicaba - SP, durante o ano de 2012. Para isso foram coletadas sementes do biótipo resistente no município de Matão, São Paulo, e as sementes do biótipo suscetível no município de Piracicaba, São Paulo. A determinação do fator de resistência entre estes biótipos ao glyphosate foi determinas a partir da elaboração de curvas de dose-resposta no estádio de desenvolvimento de 3 a 4 perfilhos do capim amargoso. Em seguida, foram conduzidos experimentos para avaliar a germinação e quantificação de massa seca produzida sob efeito de diferentes volumes da cobertura do solo com resíduos de milheto. Também foram desenvolvidos ensaios para avaliar a longevidade das sementes dos biótipos resistentes e suscetíveis, conduzidas em diferentes profundidades no solo. Através do modelo de curva dose-resposta foi possível quantificar o fator de resistência (GR50) a partir do programa estatístico R obtendo o valor de 16,66, comparando-se o biótipo resistente ao suscetível. O aumento da quantidade de palha de milheto sobre as sementes proporciona diminuição do peso de matéria seca de plântulas de Digitaria insularis, tanto resistente como suscetível ao glyphosate, sendo percebida de forma mais acentuada nos tratamentos 4,0 e 8,0 ton ha-1. O biótipo resistente apresenta número de plântulas significativamente maior que o biótipo suscetível, independentemente da quantidade de palha. Não é possível concluir que as sementes dos biótipos resistentes possuem maior longevidade que as sementes dos biótipos suscetíveis, sendo que a presença de luz é indiferente para a sua germinação.The frequent use of glyphosate in production systems that involve the crops soybean and corn, resistant to glyphosate, have selected weed populations resistant to this herbicide, being very common in Brazil the occurrence of resistant populations of bitter grass (Digitaria insularis). For the rational management of these populations, there is a need of alternative measures, that involve herbicides and cultural practices, which can be applied only with the knowledge of the weed biology, however little is known about the bitter grass biology. Therefore, this study aimed to obtain basic information of the biology of populations of bitter grass susceptible and resistant to the herbicide glyphosate. For that, three assays were conducted in the Department of Crop Science at ESALQ / USP, in Piracicaba - SP, during the year 2012. For that, it was collected seeds of the resistant biotype in Matão, São Paulo and seeds of the susceptible population in Piracicaba, São Paulo. The determination of the resistance factor for glyphosate between the biotypes was performed using dose-response curves at stage 3-4 tillers of bitter grass. Following, it was evaluated the germination and quantification of dry matter produced under the effect of different amounts of coverage with millet straw. It was also developed trials to see longevity of the resistant and susceptible biotypes, conducted at different soil depths. With the model of dose-response curve, it was possible to quantify the resistance factor (GR50) from the R statistical program by obtaining the value of 16.66, compared to the susceptible biotype resistant. The increased amount of millet straw on seed caused reduction in dry weight of seedlings of Digitaria insularis, for both biotypes, being more evident in treatments of 4.0 and 8.0 ton ha-1. The resistant biotype showed significantly higher number of seedlings than susceptible population, regardless of the amount of straw. It is not possible to conclude that the seeds of resistant biotypes have greater longevity than the seeds of the susceptible biotype, and the presence of light is indifferent to its germination
Drug interactions between antineoplastic and antidepressant agents: analysis of patients seen at an oncology clinic at a general hospital
Objectives: To determine the prevalence of depressive symptoms among oncology patients and identify simultaneous use of antineoplastic and antidepressant agents.Methods: This was a cross-sectional study that interviewed 56 oncology patients using two data collection instruments: a questionnaire covering clinical and sociodemographic data and the Beck Depression Inventory-II (BDI-II), for assessment of depressive symptoms. For data analysis, descriptive statistics were used to determine the prevalence of depressive symptoms and the chi-square test was used to evaluate associations between sociodemographic and clinical variables and depressive symptoms.Results: A 26.7% (15 patients) prevalence of depression was detected. Just eight of these 15 patients (53.3%) were receiving treatment for depression. In the sample as a whole, 13 of the patients interviewed (23.2%) were taking antidepressants and 11 of these 13 patients (19.6%) were taking antidepressive and antineoplastic agents simultaneously. A total of five (8.9% of the sample) contraindicated drug interactions were detected.Conclusions:Depressive symptoms are more prevalent among cancer patients than in the general population, but they are generally under-diagnosed and under-treated. Simultaneous use of antidepressant and antineoplastic agents is common and so, in order to reduce the number of harmful adverse effects, possible drug interactions must be identified before antidepressants are prescribed to cancer patients
Curvas de dose-resposta comparativas entre os biótipos resistente e suscetível de capim-amargoso (Digitaria insularis) ao herbicida glyphosate
A utilização frequente do glyphosate em sistemas de produção da cultura do citros tem selecionado no Brasil populações resistentes de capim-amargoso (Digitaria insularis) a este herbicida, sendo importante caracterizar os níveis desta resistência para fundamentação de recomendações de medidas racionais de manejo. Sendo assim, foi conduzido um ensaio para elaboração de curvas de dose-resposta comparativa entre dois biótipos da planta daninha capim-amargoso, um resistente (R) e outro suscetível (S) ao herbicida glyphosate. O ensaio foi conduzido em casa-de-vegetação no período de fevereiro a maio de 2012, com cinco doses, do herbicida glyphosate, tendo como base a dose recomendada do herbicida, 900 g e.a. ha-1 (0,0; 450; 900; 1.800; 3.600 e 7.200 g e.a. ha-1), e a planta daninha com 3 a 4 perfilhos no momento da aplicação. Avaliou-se porcentagem de redução da biomassa seca em relação a dose 0,0 e porcentagem visual de controle, aos 14 dias após a aplicação do herbicida. O fator de resistência R/S foi de 16,66, quando baseado na redução percentual da biomassa seca, e de 20,26 quando baseado na porcentagem de controle. Sendo assim, o biótipo R tem um alto grau de resistência, maior que os já relatados na literatura, que estão em dimensões menores que 10. Alto grau de resistência pode indicar que os mecanismos de resistência ao glyphosate neste biótipo são resultantes de alteração no sítio de ação ou super expressão gênica, e não do metabolismo, como geralmente ocorre em plantas daninhas com baixos valores do fator R/S. Para determinação destes mecanismos há necessidade de novos estudos. Conclui-se também que o manejo deste biótipo deve estar fundamentado em herbicidas alternativos ao glyphosate, pois incrementos na dose de glyphosate provavelmente não são viáveis economicamente.The frequent use of glyphosate in citrus cropping systems of citrus in Brazil has selected resistant populations of sourgrass (Digitaria insularis) to this herbicide, and it is important to characterize this resistance levels for reasons of rational recommendations for management measures. Thus, an assay was conducted to elaborate comparative dose-response curves between two biotypes sourgrass weed, one resistant (R) and one susceptible (S) to glyphosate. The assay was conducted in a greenhouse from February to May 2012, with five doses of the herbicide glyphosate, based on the recommended dose of the herbicide 900 g ae ha-1 ( 0.0, 450, 900, 1,800, 3,600 and 7,200 g ae ha-1) , and the weed with 3-4 tillers at time of application. It was evaluated the percentage of the dry matter in relation to dose 0.0 of glyphosate, percentage of visual control, 14 days after herbicide application. The resistance factor R/S was 16.66, when based on dry matter and 20.26 when based on the percentage of control. Thus, the R biotype has a high degree of resistance, higher than those previously reported in the literature that are smaller than 10. High degree of resistance may indicate that the mechanisms of glyphosate resistance in this biotype are the result of changes at the site of action or super gene expression, and not to metabolism, as usually occurs in weeds with low values of R/S factor. Further studies are necessary to determine these mechanisms. It was also concluded that the management of this biotype should be based on alternative herbicides to glyphosate, because increments in the dose of glyphosate are probably not economically viable
Translation and cross-cultural adaptation of the Rating Scale for Countertransference (RSCT) to American English
Abstract Introduction: The Rating Scale for Countertransference (RSCT) - originally, Escala para Avaliação de Contratransferência (EACT) - is a self-administered instrument comprising questions that assess 23 feelings (divided into three blocs, closeness, distance, and indifference) that access conscious countertransferential emotions and sentiments. This paper describes the process of translation and cross-cultural adaptation of the RSCT into American English. Methods: This study employed the guidelines proposed by the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) Task Force for Translation and Cultural Adaptation which define 10 steps for translation and cross-cultural adaptation of self-report instruments. Additionally, semantic equivalence tools were employed to select the final versions of terms used. The author of the RSCT gave permission for translation and took part in the process. The instrument is available for use free of charge. Results: Analysis of the back-translation showed that just seven of the 23 terms needed to be adjusted to arrive at the final version in American English. Conclusions: This study applied rigorous standards to construct a version of the RSCT in American English. This version of the RSCT translated and adapted into American English should be of great use for accessing and researching countertransferential feelings that are part of psychodynamic treatment
Automatically controlled deficit irrigation of lettuce in “organic potponics”
ABSTRACT: Concerns with water crisis involve all sectors of society and irrigated agriculture remains the main water consumer. This study evaluated an agricultural production system for lettuce cultivation in greenhouse, “organic potponics”, to economize water and manure use, using a Simplified Irrigation Controller (SIC), based on soil matric potential monitoring. Five irrigation volumes were evaluated in pots with 4.8 L, fertilized with 200 g of vermicompost. One of the volumes was controlled with the SIC. The other volumes represented 130, 80, 60 and 33 % of that controlled by the SIC and all treatments received water at the same time. Shoot fresh weight, head diameter and stomatal conductance (gs) increased linearly with irrigation volumes. For shoot dry weight, number of leaves and water use efficiency (WUE), the regression was quadratic with maximum values at 126, 114 and 83 %, respectively. Leaf relative water content did not show variation among treatments and changes in some fluorescence parameters (Reo/RC, Sm, N and φR0) were much more remarkable to drought compared with the FV/ FM ratio, one of the most commonly used stress indicators. The data indicated a tradeoff between WUE and plant growth thus the economic values of water and lettuce should be taken into account to indicate the best SIC irrigation volume. Organic potponics is promising and should be further improved to save on water, labor and fertilizer use