GRAIN YIELD OF DIFFERENT SOYBEAN GENOTYPES CULTIVATED IN LOWLAND SOILS IN THREE SOWING TIMES

摘要

Soybean (Glycine max L. Merril) has been cultivated in regions of lowland soils in crop rotation with irrigated rice in order to reduce the infestation of red rice and due to the attractive soybean value in the world market. Soybean cultivation under this condition is subject to possible soil flooding, requiring recommendations of genotypes adapted to this environment. The aim of this study was to evaluate the grain yield of soybean genotypes grown in floodplain environment at three different sowing times. Cultivars used were A 6411 RG, A 7321 RG, BMX Apolo RR, BMX Ativa RR, BMX Energia RR, BMX Potência RR, BMX Turbo RR, IGRA RA 518 RR, IGRA RA 626 RR, IGRA RA 628 RR, NA 5909 RG , NS 6262 RR, NS 7100 RR, RA 728 RR and VMax RR; sown in October, November and December. The experimental design was 15 (cultivars) x 3 (times) factorial with 4 replicates. Significant differences were observed for sowing times and cultivars, as well as for the interaction between the two factors. Cultivars sown in November and December provided higher yields than those sown in October. BMX Turbo RR cultivar showed higher consistency for soybean yield in lowland, considering the sowing times evaluated. For early sowing (October and November), A 6411 RG cultivar presented higher grain yield compared to the other cultivars.