Effects of adjuvants, work pressure, spray volume and spraying nozzles on coverage, droplet deposition and severity of soybean rust in soybean crop

• Grant number: 10/02387-1
• Support Opportunities: Regular Research Grants
• Start date: June 01, 2010
• End date: May 31, 2012
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Marcelo da Costa Ferreira
• Grantee: Marcelo da Costa Ferreira
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil
• Associated researchers: Artur Franco Barrêto ; Lilian Lúcia Costa

Abstract

This study aims to evaluate the spectrum, deposition, and coverage of spray droplets as a function of adjuvants, spray volumes and spraying nozzles on the severity of the rust caused by Phakopsora pachyhizi in soybean. The experiments will be conducted in the laboratory of Particle Size and Research Farm and Extension Education of UNESP, Jaboticabal-SP, Brazil. At the laboratory will be assessing the droplet spectrum using three different models of spray nozzles (TT, TTJ and DLAD) at fifteen working pressures (200, 220, 240, 260, 280, 300, 320, 340, 360, 380, 400 , 420, 440, 460, 480 kPa) and six market adjuvants and water (control). To that will be used a particle size analyzer Mastersizer S (Malvern Instruments Ltd.). The field experiment will be carried out in a full randomized block design with four replications in a factorial (3 x 3 x 2) + 1: being three conditions (fungicide, fungicide + vegetable oil, fungicide + fosfatidilcoline and propionic acid), three spraying nozzles models (TT, TTJ and DLAD 11002), two spray volumes (150 and 200 L/ha), and an additional treatment without fungicide (control). Applications will be made at about 60 days after emergence of soybean plants on the field. Assessments of disease severity will be held weekly by the use of a diagrammatic and through the area under the curve of disease progress, as well as yield. The values obtained will be subjected to analysis of variance and means compared by Tukey test (P < 0.05). (AU)