Spray volumes for agrochemicals applied to soybean and wheat crops

The question of the spray volume for applying agrochemicals to plants has and still demands studies to continuously search for guiding parameters for technicians due to the several variables involving application technology. This experiment aimed to determine the best spray volume for applying pesticides with a boom sprayer to soybean (Glycine max) and wheat (Triticum aestivum) crops. The experiment had a completely randomized blocks design with five treatments and five replications. In soybean (crop year 2011/12), the treatments were the control (no pesticide application) and spray volume applications of 50, 100, 150, and 200 L ha-1. For wheat (crop year 2012), the treatments were the control and spray volumes of 75, 100, 125, and 150 L ha-1. The variables analyzed were the yield components. The study concluded the need for applying foliar fertilizers and performing the chemical control of diseases and pests in soybean and wheat crops. The spray volumes of 50 L ha-1 for soybeans and 75 L ha-1 for wheat were satisfactory for spraying agrochemicals with a ground bar sprayer on plants.

Deposição e uniformidade de distribuição da calda de aplicação em plantas de café utilizando a pulverização eletrostática / Deposition and distribution uniformity of spray in coffee plants using electrostatic spraying

No âmbito da tecnologia de aplicação de agrotóxicos, a pulverização eletrostática é um sistema disponível comercialmente, no entanto, pouco empregado, devido à existência de algumas divergências quanto à eficiência desse sistema, razão pela qual o entendimento dessa tecnologia e suas interações com a planta tornam-se necessários. Nesse contexto, objetivou-se avaliar a utilização da pulverização eletrostática na cultura do café quanto à eficiência de deposição e a uniformidade de distribuição da calda de aplicação. Utilizou-se um pulverizador eletrostático, marca Electrostatic Spraying Systems, modelo ESS MBP 4.0. O experimento foi instalado no delineamento de parcelas subsubdivididas (2x3x6), com dois sistemas de pulverização (sistema eletrostático ligado e desligado), três partes da planta (superior, médio e inferior) e seis posições de coleta das folhas, com quatro repetições. Quanto à uniformidade de distribuição, observou-se que houve maior variabilidade na deposição, quando o sistema eletrostático permaneceu ligado, com maior deposição na parte externa do dossel. Os valores de coeficiente de variação para o sistema eletrostático ligado e desligado foi de 40,3 e 33,08%, respectivamente. O sistema eletrostático foi eficiente na pulverização em plantas de café e proporcionou aumento de 37% na deposição da calda de aplicação em relação ao sistema eletrostático desligado.

In the scope of the application technology of pesticides, electrostatic spraying is a system commercially available, however, little used because there is some disagreement as to the efficiency of this system, so understanding this technology and its interactions with the plant become necessary. In this context, the aim of this study was to evaluate the electrostatic spraying on coffee as to the deposition efficiency and distribution uniformity of spray. We used an electrostatic sprayer, manufactured by Electrostatic Spraying Systems Co., model ESS MBP 4.0. The experiment was set on split plot design, (2x3x6), with two spraying systems (electrostatic system on and off), three parts of the plant (top, medium and bottom) and six positions of leaves collection, with four replications. As for the distribution uniformity of spray, it was observed there was more variability in the deposition when the electrostatic system remained on, with higher deposition in the outer canopy. The coefficients of variation for the electrostatic system on and off were 40.3 and 33.08%, respectively. The electrostatic spraying system was effective in coffee plants and increased spray deposition of 37% compared to when the electrostatic system was off.