Godwin O. Chukwu
Poor knowledge of water requirements of sweet potato (Ipomoea batatas [L.] Lam) limits irrigation water management to produce the crop throughout the year. Crop evapotranspiration and irrigation water requirement of sweet potato were therefore assessed theoretically at Umudike (05° 29’N; 07° 33’E), southeastern Nigeria, using Blaney-Criddle equation. Seasonality comprised dry season (December, January, February and March) and wet season (May, June, July and August). Climatic period comprised 10 years (1984-1993) and 63-year average. There were no significant differences in crop evapotranspiration between seasons, climatic periods and their interactions. Mean seasonal crop evapotranspiration were 557.1 and 538.2 mm for the dry and wet seasons respectively. Mean seasonal irrigation water requirements were 454.9 mm in the dry season and zero in the wet season to enhance judicious use of water resources to produce sweet potato throughout the year in southeastern Nigeria.