Physiological Basis of Yield Differences in Quality Protein Maize Genotypes of Different Maturity Groups

Yield performance of early maturing maize (Zea mays L.) varieties in the rainforest agroecology of southwest Nigeria, is lower than that of intermediate varieties and that there was no yield advantage in the late varieties over the intermediate maturing varieties. However, the physiological basis of yield differences is yet to be fully investigated. This study was carried out to investigate the physiological basis underlying yield differences in quality protein maize genotypes of different maturity groups. Field experiment was conducted as randomized complete block design (RCBD) with three replicates at Institute of Agricultural Research and Training, Obafemi Awolowo University, Moor Plantation, Ibadan during 2013 and 2014 cropping seasons. The results indicated that season influenced days to 50% Anthesis (DTA), days to 50% silking (DTS), anthesis silking interval (ASI), plant height (PLHT), ear height (EHT), ear per plant (EPP), ear aspect (EASP), kernel width (KWDT) and grain yield (GYD). Maturity groups also influenced DTA, DTS, PASP, PLHT, EHT, and with no effect on GYD. The overall mean grain yields across seasons were 4.44, 4.16, 3.64 and 3.36 t/ha for season 1, 2, 3 and 4, respectively. It was concluded from this study that all the maturity groups used had similar grain yield.