Effect of Nozzle Angle and Air-Jet Parameters in Air-Assisted Sprayer on Biological Effect of Soybean Asian Rust Chemical Protection

Abstract

Aiming at improving the efficiency control of Phakopsora pachyrhizi, this research evaluated different application techniques, using spray deposits and yield parameters of soybean crop. Two experiments were carried out in the experimental area of FCA/ UNESP -Botucatu, SP, Brazil, in the soybean crop, Conquista variety, in the 2006/2007 season. The first experiment was arranged in random blocks with eight treatments and four replications. The treatments were conducted in factorial arrangement 4x2 (four air levels 0, 9, 11 and 29 km/h combined at two nozzle angles 0 and 30°) using AXI 110015 nozzles. Ten plants on each plot were selected for sampling spray deposits. Artificial targets were fixed on plants, two in the top and another two in the bottom part of plants (abaxial and adaxial leaf surface each one). For deposit evaluations, a cupric tracer was used and the amount of deposits was determined by a spectrophotometer. The second experiment was carried out in the same place and the treatments were of the same arrangement as the previous experiment, including control treatment (untreated plants). The spraying with triazole fungicide was realized in R2 and R5.2 growth stages of soybean with 142 l/ha spray volume. The nozzle angled of 30° combined with maximum air speed promoted the highest spray deposits on the soybean crop and influenced positively the control of the soybean Asian rust as well in the productivity of this crop.

Enhancing Soybean Seed Coverage with Rhizobium Inoculation in Pneumatic Row Crop Planters: A Strategy for Improved Crop Yield

“…The results showed that a nozzle angle of 30° combined with the maximum air speed resulted in the highest spray deposits on the soybean crops, leading to an improved control of Asian soybean rust and increased productivity. It is important to note that the nozzle angle used in this study differs from that employed in the present research …”

“…It is important to note that the nozzle angle used in this study differs from that employed in the present research. 19…”

Distribución espacial de la pulverización generada por diferentes diseños de pastillas hidráulicas

“…Panneton et al, (2000), encontraron, en un ensayo con cortina de aire, que una velocidad de aire superior a 25 m s -1 acoplada con un ángulo de chorro de aire de +20° y una pulverización fina, aumenta tanto la cobertura de partes ocultas de las plantas como la penetración de rociado hacia el fondo del dosel. Souza Christovam et al, (2010) realizaron 2 ensayos con cuatro niveles de aire 0 m s -1 , 2,5 m s -1 , 3 m s -1 y 8 m s -1 combinados en dos ángulos de boquilla (0° y +30°) usando pastillas Delavan 80-3R a 3,9 bar para obtener gotas de 230 µm de DVM. El segundo experimento se llevó a cabo en el mismo lugar y los tratamientos fueron con la misma disposición que el experimento anterior, pero con pastillas Delavan 80-5R a 1,5 bar para obtener gotas de 400 µm de DVM, incluyendo como tratamiento de control plantas no tratadas.…”

“…En un análisis general de las posiciones verticales, se encuentran resultados contradictorios con los antecedentes de deposición de las caras delanteras y traseras de objetivos verticales de Wolf & Cadwell (2013), quienes informaron valores más altos en la cara delantera, o frontal, que en la cara trasera de los objetivos, explicados por la componente horizontal del abanico de pulverización en el sentido de avance de la máquina. En la búsqueda de alcanzar una mayor uniformidad de distribución entre ambas caras los trabajos de Ozkan et al, (2012), Wolf & Peng, (2011), Scudeler & Raetano (2006, Friesen & Wall (1991), Panneton et al, (2000), De Souza Christovam et al, (2010, Combellack & Richardson (1985), Richardson (1987) y Jensen & Nielsen (2008) muestran mejoras para las pastillas que poseen una proyección de abanicos simples o dobles con ángulos diferentes de 0° con respecto a la vertical, que para este ensayo fueron 3 de las pastillas CC, DD y DAP. Sin embargo, solo se observaron mejoras en la posición AdV.…”