Pepper (Capsicum annuum L.) responses to surface and drip irrigation in southern Tunisia

Field experiments were performed to study the impact of two different irrigation systems (surface drip and surface) on water use efficiency and yield components of a pepper crop (Capsicum annum. L). Irrigation scheduling was carried out based on estimated crop evapotranspiration (ETc) using crop coefficients for pepper and reference evapotranspiration ETo calculated using the Penman-Monteith equation (Allen et al., 1998). The crop received total water needs computed according to Veirmeiren and Jobling (1983) procedure for surface drip irrigation. Border irrigation was scheduled by Cropwat model (Smith, 1992). Experimental plots were irrigated simultaneously during the appropriate duration for each one and received the same nutrients (N, P, and K) ratio. Comparison was made on fruit number per plant, fruit weight, fruit weight by harvest and yield per unit surface. The results showed that compared with surface irrigation, drip irrigation presented a significant difference in total fruit yield and water use during cropping season (May to September). With drip irrigation, average yield was 19.73 kg m2 which was 68% greater than that irrigated with surface irrigation (11.90 kg m2). Applied water volume by unit production (m3/kg) was 0.38 for drip and 1.05 for border, respectively. Drip irrigation increased fresh pepper fruit yield with a reduction of 60% in water use compared to traditional surface irrigation.