Water Use Efficiencies of Selected Indigenous Vegetables in Southwestern Nigeria.

Water Use Efficiencies of Seleted Indigenous Vegetables in Southwestern Nigeria Oyedele, D.J. and Shittu, K. A. Department of Soil Science and Land Resources Management, Obafemi Awolowo University, Ile-Ife, Nigeria Dry season is the most profitable period for production of vegetables in southwestern Nigeria. Availability of water is the most critical factor limiting vegetables production in this period. However, information on the water use characteristics of most under-exploited vegetables of southwestern Nigeria are not documented. This is required for effective water management and profitable production of these vegetables. The study was therefore aimed at determining the crop coefficients and the water use efficiencies of selected under-utilized vegetables in two agro-ecological zones of southwestern Nigeria in response to different rates of urea-N fertilizer application. Field and lysimeter studies were conducted in late 2013 and early 2014. Urea-N at the rates of 0, 40, 80 and 160 kg/ha N were applied to Odu (Solanum nigrum), Ogunmo (Solanum scabrum) and Igbagba (Solanum macrocarpon). The study was had a randomized completed block design with four replicates. The soil water content was monitored daily with the aid of a TDR soil moisture sensor, while the ambient weather conditions were measured with the Watchdog automatic weather station. The optimum fresh leaf harvest for the three vegetables at was between 40 and 80 kg/ga N. On the average, the crop coefficients (Kc) for odu, ogunmo and igbagba at the middle stage of growth were 1.05, 1.15 and 1.05. The study showed that Odu, Ogunmo and Igbagba required 125, 102 and 50 mm of water per kg of fresh vegetables. The vegetables were more efficient in the use of available water in the dry season than in the wet season.