Efeito do acibenzolar-s-methyl (Benzothiadiazole), como indutor de resistência sistêmica em soja (Glycine max cv. FT-Cristalina), sobre heterodera glycines

Abstract

The systemic acquired resistance is an important self defense mechanism of plants against diseases and it can occur naturally or be induced with chemical products. The purpose of this work was to evaluate the effect of acibenzolar-S-methyl (benzothiadiazole) on the induction of resistance to soybean cyst nematode (Heterodera glycines). The experiment was carried out under greenhouse conditions, at Escola de Agronomia, Universidade Federal de Goias, in a completely randomized design with 5 treatments and 6 replications. Inoculum consisted of race 4 of H. glycines naturally infested soil, from Chapadão do Céu county. The soybean cv. FT-Cristalina was used for all experiment. Treatments were as follows: 1) control; 2) acibenzolar-S-methyl 0.15 g/l foliar spray; 3) acibenzolar-S-methyl 0.30 g/l foliar spray; 4) acibenzolar-S-methyl 0.15 g/l soil drench; 5) acibenzolar-S-methyl 0.30 g/l soil drench. Treatments were applied 3 times at 15, 30 and 45 days after sowing. At the end of the crop cycle, evaluations were made on number of H. glycines females on roots, number of cysts per 100 cm3 of soil, and number of eggs per cyst. Significatly differences were not observed between treatments although fewer females occurred when the product was applied as a soil drench and, when it was applied as a soil drench at the higher concentration, on viable cysts in soil.