Espaçamentos de semeadura de soja, cv. bmx ativa, e interferência sobre o progresso de ferrugem asiática e rendimento da cultura

Abstract

The adoption of different plant arrangements in soybean can promote morphological changes in plants, influencing grain yield. The objective of this work was to evaluate the severity of Asian soybean rust, and the productivity components of cv. BMX Ativa RR, depending on different sowing spacings. The experiment was carried out in the experimental area of the Universidade Federal da Fronteira Sul, campus Erechim, in the 2020/21 crop season, under a completely randomized design, with four replications, in a 4x2 factorial arrangement, as follows: four spacings between lines (17; 34; 51; and 68 cm); and two managements of fungicide application (with and without). The following were evaluated: disease severity to estimate the area under the disease progress curve (AUDPC); the control (%) of Asian rust; number of pods per plant; number of grains per pod; thousand grain weight (g); and productivity (kg ha-1 40 ). The application of fungicides provides less disease progress and ensures control of Asian soybean rust by up to 79%, regardless of the sowing spacing used; however, the spacings did not interfere with the higher incidence of the disease. There is no influence of sowing spacing on the thousand-grain weight variable. The strategy of increasing the sowing spacing (68 cm) resulted in a reduction in crop productivity, contradicting the initial expectation of the research.