REAÇÃO DE CULTIVARES DE SOJA À MANCHA PARDA SOB DIFERENTES TÉCNICAS DE MANEJO

Abstract

The objective of this study was to evaluate the reaction of soybean (Glycine max) cultivars to brown spot (Septoria glycines) under different crop management methods. In this study the effects of the following crop management techniques were evaluated on five soybean cultivars (Msoy9001; Msoy8411; Conquista; Emgopa313; A7002): (a) fungicides and hormones, and; (b) time of planting (October, November and December). The experiment was set in Cristalina, GO, Brazil, in a randomized complete block design with eight replications in a factorial scheme (5 x 3 x 4). The chemical control of brown spot was tested as following: 1) Tetraconazol (T) (0.35 L ha-1) Thiophanate methyl + (TM) (0.4 L ha-1); 2) Stimulate ® [indolbutiric acid 0.005%, kinetin 0009% and giberelic acid (GA3 0.005%) (0.10 L ha-1)] + T (0.35 L / ha) + TM (0.4 L ha-1); 3) T (0.5 L ha-1), and; 4) control without any product. For each plot was evaluated the disease severity and incidence, and yield of seeds. Msoy8411 and Emgopa-313 planted in November presented the lowest amount of disease, and the highest seed yield. Considering the analysis of all cultivars, the chemical treatments that significantly reduced disease were Tetraconazol (0.5 L ha-1) and the chemical combination [Stimulate ® (0.10 L ha-1) + Tetraconazol (0.35 L ha-1) + Thiophanate methyl (0.4 L ha-1)].