Effects of row width and plant population on an early type of maize (Zea mays)

Abstract

Two field experiments conducted in Guaiba, Rio Grande do Sul State, Brazil, of three row widths (50, 80 and 110 cm) and four plant populations (30, 50, 70 and 90 thousands plants/ha) on an early maize hybrid. The first experiment (1969/70) had a long period of water stress just before tasseling and showed no row width effect on grain yield (1.250 kg/ha, average). High sterility (29% average) and a sharp decrease in leaf area were the main causes of the lack of responses. For the second experiment (1970/1971) when water was in good supply, the narrowest row (50 cm) outyielded the widest row (110 cm) only at the population of 70.000 and 90.000 plants/ha, mainly due to a greater ear weight. Plant sterility (3%) and the period between pollen shedding and silking were little affected. There was interaction beteween row width and plant population only for grain yield and ear weight.