IRRIGATION FREQUENCY AND DEPTH TO THE WATER-TABLE EFFECTS ON DRIP IRRIGATED TOMATOES

A field experiment was conducted for two crop seasons to investigate the effects of irrigation frequency and depth to the water table on growth and yield of tomatoes (Lycopersicon esculentum Mill.) grown on a sandy soil. Drip irrigation treatments were: 1) three irrigations per day, 2) one irrigation per day, and 3) interrupted irrigation (irrigation was withheld for 18 d). Plant height and above ground biomass were not affected by irrigation treatment. Average soil-water potential (SWP) and leaf-water potential (LWP) were reduced by withdrawing irrigation and lowering the depth to the water table. Root distribution was influenced by irrigation treatment with greater root-length density in 0-15 cm (0-6 in.) portion of the profile in the one irrigation per day treatment. Tomato yield was not affected by irrigation frequency nor was yield reduced by temporarily withholding irrigation for 18 d beginning at 5 wk after transplanting with the presence of a water table at 0.9 to 1.25 m from the top of the plant bed.