INSECTICIDE APPLICATION SPEED IN THE CONTROL OF LEPIDOPTERAN PESTS IN SOYBEAN1

Lenio Cesar Moraes De Camargo,Carlos Tadeu Dos Santos Dias,Danilo De Brito Garcia,Danilo Augusto Sarti,Amarildo Pasini,Otávio Jorge Grígoli Abi Saab

doi:10.1590/1983-21252020v33n108rc

Lenio Cesar Moraes De Camargo, Carlos Tadeu Dos Santos Dias + Show 4 more

Open Access

https://doi.org/10.1590/1983-21252020v33n108rc

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Abstract

ABSTRACT During the chemical control of pests, diseases and weeds, great importance is given to the phytosanitary product and little attention to the application technology. The control of soybean pests did not escape the general rule and, therefore, some pests known as secondary, and even nonexistent, became responsible for great damage to the soybean crop. The objective of this work was to test the application of insecticide at different speeds (5 and 16 km h-1) by varying the rates of application in 108 to 110 and 199 to 216 L ha-1 to quantify the difference in the coverage percentage of the applied insecticide in the canopy of soybean plants, and to verify the interaction of these factors with efficacy parameters for the control of caterpillars (Helicoverpa armigera and Chrysodeixis includens). In general, the highest leaf coverage by the insecticide was observed in the upper part of the canopy, regardless of the rate and speed of application, resulting in lower leaf damage. For the middle and lower thirds of the plant, the decrease in speed influenced more the decrease in leaf damage by the caterpillars than the increase in the spray volume.

Highlights

In order to achieve success in an application, the spray drops need to be deposited on the desired target
The objective of this study was to test the application of insecticide at different speeds (5 and 16 km h-1) and application rates (108 to 110 and 199 to 216 L ha-1) to quantify the difference in the percentage of coverage for the insecticide applied in the canopy of soybean plants and, to verify the influence of these factors on efficacy parameters for the control of caterpillars (Helicoverpa armigera and Chrysodeixis includens)
In regard to the damage caused by Chrysodeixis includens in the leaves collected at 1 days after insecticide application (DAA) (Table 4), in the upper third there was no significant difference in damage due to the good coverage for the lowest application rate, regardless of the speeds adopted

Summary

Introduction

In order to achieve success in an application, the spray drops need to be deposited on the desired target. With the increase in displacement speed, the operational capacity increases Factors such as operating pressure, flow rate and nozzle outlet orifice should be regulated in such a way to satisfy the quality of applications, adjusting the application technology to the required conditions (WEBER et al, 2017). Energy, economic and operational costs associated with their use, applications in liquid form tend to use less and less water volume per area. This trend is mainly linked to the cost of transport to the field and the waste of time due to interruptions, displacement and refill of the sprayers (BALAN et al, 2008). The higher the application rate, the greater the increase in the percentage of coverage on the applied target (ROMÁN et al, 2009) and the higher the tendency of penetration of the drops in the canopy of crops

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