Effect of sowing density on yield and profitability of a hybrid corn under tropical conditions

A high sowing density in maize is a widely used management practice for increasing crop yield; this method increases intraspecific competition for solar radiation, nutrients and water, so yield per plant is reduced, but a greater number of plants is harvested. However, different corn hybrids present a differential behavior because some are tolerant and some are susceptible to this condition, as determined by their plasticity in adjusting their morphology and phenology. The aim of this study was to identify the optimum sowing density, in technical and economic terms, of a new hybrid corn named 30K73 YG RRFlex since no information is available for tropical conditions. This study was carried out in the province of Tolima, municipality of Valle de San Juan, Colombia, using a completely randomized block design in divided plots; five sowing densities determined by six spatial arrangements, two distances between rows (0.7 and 0.8 m) and three numbers of plants per linear meter (7, 8 and 9) were assessed. The treatments did not generate a nitrogen deficiency in the plants, and the evaluated hybrid developed morphological adjustments at the leaf level in order to maintain constant solar radiation interception. For yield, there were no significant variations, so the yield was similar for all of the evaluated treatments. The best treatment was 87,500 plants ha-1, with a yield of 9,916.66 ± 1,078 kg ha-1 and a profitability of 58%.