COMPARATIVE ANALYSIS OF GROWTH AND YIELD RESPONSES OF OPEN AND HYBRID MAIZE VARIETIES TO PLANTING DENSITIES IN NIGERIA'S RAINFOREST-SAVANNA ZONE

Sub-optimal plant density is a major factor limiting profitable maize (Zea mays. L) Production in Nigeria. Over the years, the maize planting density recommendation has remained at 53,333 plants per hectare across maize genotypes and agroecologies of the country. However, increasing plant density has the potential to enhance maize resource utilisation and productivity. Two open-pollinated (DMRLSR-W & SUWAN-1) and two hybrids (OBASUPER-1 & OBASUPER-2) maize were grown on the field under two plant densities; 80,000 and 53,333 plants/ha arranged in split-plots using Randomised Complete Block Design and three replications at the Institute of Agricultural Research and Training, Ibadan in 2017 and 2018 growing seasons. Data were collected on maize growth parameters, yield components and grain yield (GY) and subjected to Analysis of Variance at 95% level. Plant density (80,000) was significantly (P<0.05) higher in GY (3.29 t ha-1) than in 53,333 plants / ha (2.83 t ha-1). The two maize varieties showed no significant differences in grain yield at P<0.05. Maize varieties OBASUPER-1 (189.21 cm) and SUWAN-1 (191.85 cm) showed higher plant heights than OBASUPER-2 (175.04 cm) and DMRLSR-W (176.57 cm). Maize variety OBASUPER-1 (30.38 g) had higher 100-seed weight than OBASUPER-2 (27.58 g), DMRLSR-W (27.08 g) and SUWAN-1(27.42 g). Planting maize at an increased plant density of 80,000 plant stands ha-1 significantly enhanced the yield of maize compared to 53,333 plants ha-1. This study therefore suggests further exploration of these varieties and others across high plant densities and agroecologies for optimal resource utilization and output benefits