Assessment of Water-use Efficiency of Drought Tolerant Maize (Zea mays L.) Varieties in a Rainforest Location

Abstract

Aims: To evaluate drought-tolerant (DT) maize varieties for water use efficiency at the seedling and grain filling stages and determine the relationship between water use efficiency and grain yield of the DT maize varieties since information about the water use efficiency of these DT maize varieties is limited in literature. Study Design: The experiment was laid out in a Randomized Complete Block Design (RCBD) in three replicates. Place and Duration of Study: The planting was carried out just at the beginning of the early cropping season (March) (Drought) as well as the peak of rain for early cropping season (June)(Rain-fed) of 2015 at the Teaching and Research Farm of Obafemi Awolowo University, Ile–Ife (7º28ˈN 4º33ˈE and 244 m above sea level), Nigeria. Methodology: Water Use Efficiency traits and grain yield data were obtained from each plot. Daily values of evapotranspiration, rainfall, minimum and maximum temperatures were also taken from the meteorological station of the Teaching and Research Farm, Obafemi Awolowo University, Ile-Ife. Data collected were subjected to Analysis of variance (ANOVA) and correlation among Water Use Efficiency (WUE) traits and grain yield data were carried out. Results: The varieties that recorded the highest cumulative water used for grain filling are 2012TZE-WDTC4STRC5 and 2014TZE-WDTSTR with 177.60 mm while the varieties with lowest cumulative water used are 2004TZE-WDTSTRC4 (164.93 mm) and Obatanpa (Local Check) (158.93 mm) under drought, On the contrary, Obatanpa (204.58 mm) was among the varieties with the highest grain-filling cumulative water used under rain-fed condition. The varieties with the highest grain-filling cumulative water used for growth rate are 2014TZE-WDTSTR and 2012TZE-WDTC4STRC5  under drought (13.74 g/day and 11.31 g/day respectively) and rain-fed conditions (10.13 g/day and 10.82 g/day respectively) while the lowest grain-filling growth rate was obtained by variety 2004TZE-WDTSTRC4 (7.02 g/day) under drought and (7.05 g/day) under rain-fed conditions. Conclusion: The highest grain-filling water use efficiency was obtained in varieties 2012TZE-WDTC4STRC5 and 2014TZE-WDTSTR. There was no significant relationship between the water use efficiency traits and grain yield of the DT maize varieties used in this study.