Planting date effects on maize (Zea mays L.) growth and development in the rainforest of southwestern Nigeria

摘要

This study was conducted to determine the optimum planting date for maize (Zea mays L.) to cope with the negative impacts of climate change in the marginal rainforest agro-ecology as typified at Ile-Ife, SW Nigeria. Five maize varieties were planted weekly, in 3-replicate randomized complete block design experiments at the Obafemi Awolowo University Teaching and Research Farm, throughout the 2016 and 2017 cropping seasons. The varieties were monitored for seedling and adult plant traits including grain yield with its components. Statistical analysis showed significant effect of planting dates (DOP) on all traits. The first few DOPs in March and April had the highest grain yield which reduced with delayed planting till June and increased again mid July/August before finally dropping off thereafter. The higher yield in the earlier dates each year, was due to early flowering and taller plants with higher ear placement. Planting after the first few rains in March/April was the optimum for the first cropping season, and late July to mid-August was best for the second cropping season in this agroclimatic zone. Planting beyond these periods results in poor grain yield and pre-disposes the crop to terminal drought, which could result in complete crop failure.