IInfluence of sowing times and plant populations on the agronomic performance of maize hybrids

Resumo

The sowing time, along with increased plant density and the choice of the hybrid, are among the main factors to obtain higher grain yields in second-season maize. The objective was to evaluate the agronomic performance of maize hybrids grown in different plant populations and sowing times. The experimental design was in randomized blocks with subdivided plots and four replicates. The main plots consisted of four sowing times (Jan/20/2014, Feb/07/2014, Feb/28/2014, and Mar/14/2014), the subplots consisted of the hybrids (BRS 1010 and DKB 390 VT PRO2), and the sub-subplots consisted of the plant populations (45,000; 55,000; 65,000 and 75,000 plants ha^-1). Regardless of plant population, the performance of hybrids BRS 1010 and DKB 390 VT PRO2 are similar regarding grain yield, plant height, and number of rows per ear. The development of maize was better in the sow­ings performed between Jan/20 and Feb/07, and very late sowings negatively affect yield. Among the hybrids studied, in a population ranging from 45,000 to 75,000 plants ha^-1 there is a reduction in ear diameter and hundred-grain weight, although without affecting yield.