Effect of Deficit Irrigation Levels on Yield and Water Productivity of Some Maize Varieties in a Semi-arid Environment

The aim of this research is to determine the appropriate irrigation scheduling under three different maize varieties in Northern Guinea Savanna agro ecological zone of Nigeria. The trial was conducted during the 2015 and 2016 dry seasons at the Institute for Agricultural Research (IAR) field in Samaru (Latitude 11.11° N and Longitude 7.38°E). The experiment was laid out as a split – plot design replicated three times. Planting dates and supplementary Irrigation levels were in the main plots while maize varieties formed the sub-plots with the planting dates at 10days interval starting from March and February respectively. Three levels of irrigation were imposed based on levels of cumulative pan evaporation (Epan ) values of 1.0 Epan (EI1), 0.70 Epan (EI2) and 0.40 Epan (EI3). Results from the two trials, revealed more efficient utilization of soil moisture by crops irrigated with 70 CU irrigation regime (6.91 and 6.97 kg grain/mm water respectively for the two seasons) while the least efficient water use was recorded by the full CU treatment (6.63 and 6.93 kg grain/mm water respectively) with relatively higher grain yields of 14% and 20% more than the 70 CU and 40 CU regimes respectively in 2015. Similar trends were recorded in the case of cob weight, 100 seed weight, seed/cob, shelling percentage and harvest index. In 2016 season, the similar trend was observed indicating the highest grain weight (3348.0 kg/ha) recorded by the full irrigation treatment which was statistically higher than (2724.0 and 2072.0 kg/ha) respectively for the 0.70 and 0.40 CU regimes. The best performing variety in terms of efficient water use and relatively high yield was the medium maturing variety (V3).