Influence of Emulsifiable Concentrate Formulation on the Physical Properties of the Fluid, Spray Characteristics, and Insecticide Deposits on Stored Grains

Abstract

In stored grains, smaller depositions and great variations with regard to theoretical insecticide doses are frequently found. The objective of this work was to evaluate the influence of the emulsifiable concentrate formulation on the physical properties of the liquid, volumetric distribution, droplet spectrum, and insecticide deposits on stored grains. To determine its physical properties, the applied mix was prepared at a concentration of 0.4% of commercial product. Volumetric distribution was used as an evaluation parameter in a model TJ-60 8002EVS hydraulic nozzle study, and clean water and insecticidal mix were used as test fluids. After the effective swath width (esw) had been determined for both fluids, an application system was built to apply theoretical concentrations of 10 and 0.5 mg kg-1 of fenitrothion and esfenvalerate, respectively. Mix viscosity was 82% higher than water viscosity; conversely, surface tension in the mix corresponded to 49% of the water surface tension value. For water and mix, esw values were 0.425 and 0.60 m, respectively. Deposits of both insecticides at the 0.60 m esw were significantly higher (P<0.05) than deposits at the 0.425 m esw. The results obtained demonstrate the great influence of emulsifiable concentrate formulation on the physical properties of the fluid, spray characteristics, and insecticide deposits on stored grains.

Surface tension, hydrogen-ion potential and electrical conductivity in spray solutions of plant protection products and adjuvants

“…Ainda segundo o autor, se as propriedades da gota pulverizada não forrem otimizadas, grande parte da pulverização pode se perder, demonstrando a importância do conhecimento da tensão superficial das caldas. Vásquez-Castro et al (2007), avaliando propriedades físicas de caldas inseticidas, observaram que a mistura entre produto e adjuvante resultou em redução de 49% na tensão superficial em relação à água. De maneira semelhante, Cunha, Alves e Reis (2010), também concluíram que todos os adjuvantes avaliados reduziram a tensão superficial da calda em relação á água, corroborando com os resultados deste trabalho.…”

Impact of resistance to fenitrothion and esfenvalerate on the control of Rhyzopertha dominica (Coleoptera: Bostrichidae) in stored wheat

“…Grains were treated in order to obtain the theoretical concentration of 10 and 0.5 mg.kg -1 fenitrothion and/or esfenvalerate, respectively, as recommended by the manufacturer on the labels. The method of application in use was proposed by (Vásquez-Castro et al 2007a, 2007b. Three replications were performed for each insecticide.…”

Insecticidal Effect and Residual Action of Fenitrothion and Esfenvalerate onSitophilus oryzaeandS. zeamais(Coleoptera: Curculionidae) in Stored Maize and Wheat

“…The method of application would be grounds for such contradicting results as these authors treated a small amount of grains within glass vials, which were then scrambled to distribute the insecticide as uniformly as possible. In the present experiment, grains were not revolved after treatments so that avoidance invalidates the studies as to applicationtechniques, responsible for the uniform distribution of insecticides [19,38,39].…”