Effects of planting date, environments and their interaction on grain yield and quality traits of maize hybrids.

Maize is one of the most important staple food crops for most low-income households in the Southern African region. Erratic and inconsistent rainfall distribution across maize-growing areas is a major threat to maize production. Late rains in recent years have forced farmers to plant later than the optimal planting dates, leading to poor maize quality being reported by industry, which raised the question of the influence of later planting dates on grain yield and quality traits of maize. Three yellow and three white maize hybrids were evaluated at three planting dates in three different production environments for three consecutive seasons using a randomized complete block design with three replications. The second and third planting dates caused a significant yield decrease of 23.37 % and 53.73 % from the first planting date across environments, respectively. Planting date three was associated with decreased grain yield, starch content, and increased protein but no significant change in fat and fiber content. Some hybrids yielded relatively well at all planting dates. In conclusion, the early planting date was the most suitable for maize grain yield and starch production in the maize-growing areas of the country. However, planting in January should be avoided at all costs, as it leads to very low yield and poor grain quality.