Crescimento de dois cultivares de soja submetidos a aplicações de herbicidas e fungicidas

Abstract

Effects of herbicide and fungicide applications on the growth of two soybean cultivarsPesticide application may change crop growth and metabolism, leading to negative or positive consequences. Strobilurin fungicides have been reported to increase soybean yield even without incidence of diseases, suggesting that physiological changes should be investigated. The objective of this study was to evaluate the growth of two soybean cultivars (MG/BR46 Conquista and BRS Valiosa RR) subjected to herbicide and fungicide (strobilurin and/or triazole) applications. Two field trials were carried out with treatments arranged in a split-plot in time design (5 x 12), with five herbicide combinations (glyphosate at 720 g ha -1 or sethoxydim (230 g ha -1 ) + bentazon + chlorimuron-ethyl (480 + 11,25 g ha , epoxiconazole a 50 g ha -1 or pyraclostrobin + epoxiconazole (66,5 + 25 g ha -1 )) in the plots; and the dates of evaluation were considered as the split-plots, varying between 30 and 120 days after sowing. Herbicide application did not affect the growth of soybean cultivars. Application of the strobilurin )); e como subparcelas foram consideradas as datas de avaliação entre 30 e 120 dias após semeadura. A aplicação de herbicidas não alterou o crescimento dos cultivares de soja. A aplicação de fungicidas do grupo das estrobilurinas associado a triazóis promoveu maior acúmulo de massa de matéria seca e área foliar. Ainda a aplicação desses fungicidas em R2 (pleno florescimento) e R5.1 (enchimento de grãos) resultou em maiores valores de taxas de crescimentos absoluto e relativo, assimilatória líquida e de crescimento da cultura em período próximo ao final do ciclo da cultura, diferenciando, inclusive, dos tratamentos com aplicação somente de triazóis. Palavras-chave:Glycine max (L.) Merr., estrobilurinas, triazóis, pyraclostrobin, TAL.

Análise de crescimento e partição de assimilados em plantas de tomateiro cv. Micro-Tom submetidas ao nitrogênio e piraclostrobina

“…Segundo Júnior et al (2013) a aplicação de piraclostrobina causa incremento na matéria seca, conforme verificado pela taxa de crescimento relativo. Conforme Tsumanuma et al (2010) a aplicação de estrobilurina associada a triazol em R2 e R5.1 em plantas de soja, resulta em maiores valores de taxas de crescimento absoluto, crescimento relativo e de crescimento da cultura.…”

Photoynthetic and productive increase in tomato plants treated with strobilurins and carboxamides for the control of Alternaria solani

“…All plants at the beginning of development (at 14 DAT) had the same developmental pattern, however, during treatment applications, it was generally observed that plants treated with strobilurin and carboxamides presented greater initial development and biomass accumulation when compared to controls. Several studies have reported the physiological effects of these substances on maize (Lima et al, 2009), soybean (Tsumanuma et al, 2010), common bean (Jadoski et al, 2015), carrot (Colombari et al, 2015), sunflower (Tsialtas et al, 2017) and Japanese cucumber (Amaro et al, 2018), where positive effects on biomass accumulation and productivity were observed. In Arabidopsis thaliana Van Dingenen et al (2017) observed that the application of strobilurins promoted greater plant growth, confirming the positive effects of these substances.…”

“…Since the advent of these molecules, primarily strobilurins in the 1980s and more recently carboxamides, many researchers have observed that in addition to effective disease control, there are simultaneous effects on plant physiology, increasing crop yield (Fagan et al, 2010;Diaz-Espejo et al, 2012;Kanungo and Joshi, 2014;Van Dingenen et al, 2017). Numerous studies have shown positive effects of the application of these molecules on different crops such as soybeans, beans, corn, bananas, carrots, sunflowers, cucumbers, melons, tomatoes and grapes (Lima et al, 2009;Tsumanuma et al, 2010;Lima et al, 2012;Diaz-Espejo et al, 2012;Colombari et al, 2015;Ramos et al, 2015;Jadoski et al, 2015;Tsialtas et al, 2017;Macedo et al, 2017;Amaro et al, 2018). As reported in these studies, the main effects observed are the activation of important enzymes in cell metabolism, such as NADHnitrate reductase enzyme, increasing the assimilation of nitrogen and its incorporation in different vital molecules of the plant, such as chlorophyll, also reducing ethylene production, justifying the green effect, since in addition to the higher content of pigments, senescence is delayed.…”

Efeito da aplicação de nitrogênio e de piraclostrobina em plantas de tomateiro cultivar Micro-Tom

“…Alguns autores reconhecem que, além da atuação como fungicida, a piraclostrobina tem demonstrado efeito de promoção do crescimento em certas espécies vegetais, como soja, banana, uva e milho (Lima et al, 2009;Tsumanuma et al, 2010;Diaz-Espejo et al, 2012;Lima et al, 2012). Esse efeito fisiológico positivo pode ser atribuído a uma série de fatores, como o aumento da eficiência do uso de água e de nitrogênio, a inibição da degradação da clorofila, o atraso da senescência foliar e o aumento da atividade da enzima redutase do nitrato (Venancio et al, 2003).…”