Spray nozzles for application of fungicides in common bean

Abstract

common beans (Phaseolus vulgaris) are one of the staple foods for Brazilians. Production can be reduced by the action of unwanted factors, including the occurrence of diseases. In the integrated management of diseases there is the strategy of chemical control. The objective of the study was to evaluate the influence of spray nozzles on the chemical control of diseases in common bean. The experimental design used was in randomized blocks with six treatments and four replications. The treatments consisted of control (without fungicide application on bean plants) and application of fungicides with spray nozzles hollow cone jet, double flat jet, extended range flat jet, wide angle flat jet and air induction flat jet. The sprayer used was the backpack pressurized by CO₂. The experiment was conducted in the region of Campos Gerais (Paraná, Brazil) during the 2016, 2017 and 2018 crop seasons. The variables analyzed were the incidence and severity of diseases, spray quality (covered area, density, and relative amplitude) and common bean yield components. It is concluded that the chemical control of fungal diseases in bean plants reduced the action of diseases and losses in productivity. There were significant changes in spraying quality in all variables analyzed. There were no differences among the nozzles regarding the analysis of incidence, severity and yield components of the bean crop.