Water use efficiencies of maize cultivars grown under rain-fed conditions

Abstract

Enhancing water use efficiencies of rain-fed maize is a requirement for sustainable maize production, particularly in areas prone to low/ drought and erratic rainfall patterns. This study was conducted to assess the relationship be-tween total biomass/grain yield and water use efficiencies of three maize cultivars (Golden Crystal, Mamaba and Obatanpa) grown under rain-fed conditions in a coastal savannah agro- ecological environment of Ghana. Results of the study showed that a unified linear model, WUETDM = 0.03 TDM with R2 = 0.765 and P ≤ 0.001, described adequately the relation be-tween water use efficiency and total biomass (dry matter), which is applicable for the three maize cultivars for both the major and minor cropping seasons. A linear model could only, however, describe adequately well the relation between WUEGY and GY for the major (WUEGY = 0.001 GY – 0.67; R2 = 0.996; P ≤ 0.001) and minor (WUEGY = 0.002 GY + 0.289; R2 = 0.992; P ≤ 0.001) cropping seasons for all the maize cultivars. The linear models developed for the maize cul-tivars, relating WUEGY to GY, are specific to each of the crop growing seasons, indicating that seasonal rainfall impacts significantly on harvest index of the maize cultivars but diffe-rently in each of the crop growing seasons as a results of differences in seasonal rainfall. How- ever, the models could be used to estimate wa-ter use efficiencies of each of the three maize cultivars given the appropriate TDM and GY as inputs for the environment under which the study was conducted.