Spray solution deposition and Asian rust control in soybean cultivars

Izidro Dos S De Lima Júnior,Karina De J E Martins,Bruno F Bertoncello,Antonio L Viegas Neto,Lígia M M Da S Piletti,Cristiano M A De Souza

doi:10.1590/1807-1929/agriambi.v25n12p862-867

Abstract

ABSTRACT The control of Asian soybean rust depends on fungicide efficacy and the application technology; however, the leaf architecture of soybean cultivars may also interfere in disease control. This study aimed to evaluate Asian rust control and fungicide deposition using spray nozzles in three soybean cultivars. A randomized block design was used, with treatments arranged in a split-plot scheme; the plots were three soybean cultivars (SYN 1561 IPRO, M6410 IPRO, and M6210 IPRO) and the subplots three spray nozzles (11002 BD, AIXR 110015 and TTJ60 11002), in addition to a control with no fungicide application, and four replicates. The volume median diameter, droplet coverage, leaf area index, area under the disease progress curve, 1,000-grain weight and crop yield were evaluated. The 11002BD and AIXR11005 nozzles provided better spray deposition in cultivars with lower leaf area indexes at the R1 phenological stage. Nozzles 11002BD, AIXR110015 and TTJ60 ensured better management of Asian rust than that of the control treatment, regardless of leaf area index. Cultivar SYN1561 obtained the largest grain yield and highest leaf area index in the season with the highest rainfall, regardless of the spray nozzle used.

Highlights

Asian rust is the main disease in most soybean-growing [Glycine max (L.) Merrill] countries
This study aimed to evaluate fungicide deposition and Asian rust control in three soybean cultivars, using three different spray nozzles
A randomized block design was used, with treatments arranged in a split-plot scheme in which the plots were the three soybean cultivars (SYN 1561 IPRO, M6410 IPRO and M6210 IPRO) and the subplots the spray nozzles (Table 1), in addition to a control with no fungicide application, and four replicates

Summary

Introduction

Asian rust is the main disease in most soybean-growing [Glycine max (L.) Merrill] countries. Sydow & Sydow, the first symptoms of the disease are small brown-to-dark brown lesions on the abaxial portion of the leaves (Godoy et al, 2018; Nascimento et al, 2018). Chemical control with fungicides is the primary means of controlling this pathogen, supported by other practices such as nutrition, sowing time, row spacing and biological vacuum (Stefanello et al, 2016; Godoy et al, 2018). Chemical control is only carried out with knowledge of the application technology. The choice of spray nozzles for fungicide application is an important decision, aimed at producing the most homogeneous droplets possible (Vieira et al, 2019). The nozzles must provide efficient coverage of the target to ensure minimum fungicide wastage (Prado et al, 2015)

Objectives

Methods

Results