Resistência de cultivares de soja a oídio

Abstract

Since the disease called powdery mildew (Microsphaera diffusa) has caused a relatively high damage to the soybean crop, the damage can be severe when not controlled or controlled too late and as it is considered a biotrophic fungus, the best way to contain its advance is through resistant cultivars, in addition to the application of fungicides at the right time and dose. For this, the resistance of different soybean cultivars to powdery mildew was analyzed in order to reduce the economic damage that has occurred more frequently due to the presence of the disease in the field. Therefore, to carry out the work, six soybean cultivars were sown and analyzed in the municipality of Pato Branco, namely: BMX RAIO, BMX ZEUS, NS 4823 RR, M 6410 IPRO, TMG 7063 IPRO and TMG 7260 IPRO. During the experiment, the appearance of the disease was monitored, 60 days after planting, and then the severity of the disease every 15 days, and the productivity of each cultivar was also calculated. The present work was carried out in randomized blocks with 6 treatments and 4 replications, totaling 24 plots. In this way, the application was only of herbicides and insecticides, when pests and weeds were present, thus enabling the evaluation of productivity in relation to resistance and susceptibility of the selected cultivars to the disease causing powdery mildew. The cultivar that presented the highest productivity was M 6410 IPRO, and the one that presented the lowest productivity, and consequently, the highest incidence of the disease was BMX 50I52 RSF IPRO (RAIO). The cultivar that showed the highest resistance to powdery mildew was TMG 7260 IPRO.