Evaluation of pyraclostrobin and acibenzolar-S-methyl on common bacterial blight of snap bean

Abstract

Assays were done under greenhouse conditions in order to evaluate the effect of pyraclostrobin (0.0375, 0.0750 and 0.150 mL.L -1 ) and acibenzolar-S-methyl (ASM) (0.025 g.L -1 ) in common bacterial blight on leaves of snap beans cultivar Bragança. These chemicals were sprayed at three different times: five days before; five days before + five days after; and five days after leaf inoculation with an isolate of Xanthomonas axonopodis pv. phaseoli. They were determinate the levels of polyphenoloxidase, peroxidase and total soluble proteins on inoculated and non-inoculated leaves of snap beans sprayed with pyraclostrobin (0.075 g.L -1 ) and ASM (0.025 g.L -1 ). All concentration of pyraclostrobin and ASM reduced the area under the disease progress curve (AUDPC) on leaves of snap beans, and the least AUDPC value was observed when this products were sprayed five days before + five days after inoculation. Higher levels of polyphenoloxidase, peroxidase and the total soluble proteins were observed on leaves sprayed with pyraclostrobin or ASM. Key words: Phaseolus vulgaris, Xanthomonas axonopodis pv. phaseoli, protein ResumoEnsaios foram conduzidos sob condições de casa-de-vegetação para avaliar o efeito de pyraclostrobin (0,0375; 0.0750 e 0,150 mL.L -1 ) e acibenzolar-S-methyl (ASM) (0.025 g.L -1 ) sobre o crestamento bacteriano comum em folhas de feijão-vagem cultivar Bragança. Os produtos foram pulverizados em três diferentes períodos: cinco dias antes, cinco dias antes + cinco dias após e cinco dias após a inoculação dos folíolos com um isolado de Xanthomonas axonopodis pv. phaseoli. Foram determinados os teores de polifenoloxidase, peroxidase e proteínas solúveis totais em folhas inoculadas e não-inoculadas de feijão-vagem pulverizadas com pyraclostrobin (0,075 g.L-1) e ASM (0,025 g.L-1). Todas as concentrações de pyraclostrobin e ASM reduziram os valores da área abaixo da curva do progresso da doença (AUPDC) e o menor valor da AUPDC foi observado para a aplicação dos produtos cinco dias antes + cinco dias após a inoculação. Altos teores de polifenoloxidase, peroxidase e proteínas solúveis totais foram observados nas folhas pulverizadas com pyraclostobin e ASM. Palavras-chave: Phaseolus vulgaris, Xanthomonas axonopodis pv. phaseoli, proteína

Control of Bacterial Spot of Tomato and Activation of Enzymes Related to Resistance by Chemicals Under Field Conditions

“…No influence on the production of phenylalanine ammonia-lyase, β-1,3-glucanase, or protease was observed when the other chemicals evaluated were used. Our results partially agree with those of Vigo et al (2012) on snap-bean plants where spraying acibenzolar-S-methyl and pyraclostrobin resulted in higher levels of polyphenol oxidase, peroxidase, and total soluble proteins, suggesting their involvement in the mechanisms of induction of resistance on the common bacterial blight caused by Xanthomonas axonopodis pv. phaseoli.…”

“…The physiological changes can be positive (Venancio et al, 2005) as they activate biochemical mechanisms that increase plant resistance to pathogens Venancio et al, 2003;Venancio et al, 2005;Vigo et al, 2012).…”

Plant health and yield of dry bean not affected by strobilurin fungicides under disease-free or simulated hail conditions

“…Even with the addition of a simulated hail stress, azoxystrobin and pyraclostrobin had no effect on pick value, seed weight, or dry bean yield. When environmental conditions were conducive for disease, strobilurins have been shown to protect dry bean plants as yield from treated plants tend to be greater than untreated controls (Rodrigues et al 2009;Pynenburg et al 2011;Demant and Maringoni 2012;Gillard et al 2012a, b;Vigo et al 2012;Gillard and Ranatunga 2013). However, the results of the current study indicate that dry bean management decisions, such as the application of azoxystrobin or pyraclostrobin when growing conditions are unfavourable for disease development (Kyveryga et al 2013), should be weighed against economic returns on investment (Henry et al 2011;Mahoney et al 2014b) and the potential risks associated with disease resistance development.…”

“…However, increased soybean yield due to strobilurin fungicides have been inconsistent across years and/or treatment combinations (Bradley and Sweets 2008;Swoboda and Pedersen 2009;Cruz et al 2010;Dorrance et al 2010;Nelson et al 2010;Nelson and Meinhardt 2011;Kyveryga et al 2013). For dry bean, the physiological effects of strobilurins have been investigated in South America (Rodrigues et al 2009;Demant and Maringoni 2012;Vigo et al 2012). However, to the best of our knowledge, little published information is available on the use of strobilurin fungicides for plant health effects on dry bean grown under Ontario climatic conditions.…”

Systemic Acquired Resistance of Soybean to Soybean Rust Induced by Shale Water

“…They suggest that the SAR induced genes include effector genes that confer resistance as well as regulatory genes such as transcription factors that confer that resistance is long lasting in the plant. Benzothiadiazole as a novel class of inducers of SAR, has been developed commercially as a plant activator, inducing SAR in wheat and conferring systemic protection against powdery mildew [5] [6]. Vigo et al, 2012 [6] reported that chemicals like pyraclostrobin and acibenzolar-S-methyl sprayed on snap bean induced systemic resistance against common bacterial blight caused by Xanthomonas axonopodis pv.…”