Chemical Control of Asian Soybean Rust and Its Effect in the Yield and Quality of Soybean Seeds

The objective of this study was to evaluate the effect of a foliar fungicide commonly used to control Asian soybean rust (Phakopsora pachyrhizi) in the physiological and sanitary quality of soybean seeds. The experiment was carried out during the 2012/13 field season, with six treatments and four replications arranged in a randomized complete block design. The following treatments were evaluated: T1 (no fungicide application); one application at R1 stage; two applications at R1 and R3 stages; three applications at R1, R3, and R5 stages; four applications at R1, R3, R5, and R6 stages and five applications at R1, R3, R5, R6 and R7 stages. Seeds yield, seed weight, viability and vigor assessments were used to measure the impact of foliar fungicide applications on soybean yield and seed quality. The results indicated that four fungicide applications provide higher grain yield, increased seed weight, and germination percentages within commercial standards. In contrast, the number of fungicide applications did not correlate with the sanitary quality of the seeds.