Sowing Dates and Soybean Cultivars Influence Seed Yield, Oil and Protein Contents in Subtropical Environment

The sowing date is the crop management practice with higher interference on soybean grain yield, although this interference is dependent on the genotype by environment interaction. This study was carried out to evaluate how soybean genotypes behave at different sowing times in a subtropical environment. We evaluated the grain yield, yield components, plant morphology and grain oil and protein content of four soybean cultivars (FPS Urano RR, BMX Apolo RR, BMX Energia RR and BRS 284) at three sowing dates (early, mid, and late sowing in 2010/2011 season) in Mid-South of Parana State, Brazil. Early cultivars at late sowing may have problems with mechanical harvest. The number of pods and grains differed among cultivars, and the cultivar “BRS 284” showed the best results. As an exception, the cultivar “BRS 284” showed yield stability among sowing dates. Higher amount of grain protein content occurs in middle and late sowing dates. The grain yield decreased with delay of sowing due to the reduction of the grains mass and in Southern Brazil is very important to assure high mass of seed to obtain high grain yields.