The Influence of Irrigation Strategies on Tomato Fruit Yield and Leaf Nutrient Contents

In order to assess the effect of deficit irrigation (DI) on fruit yield and leaf nutrient contents of tomatoes in the Mediterranean climate, an open-field experiment was carried out in Bursa, Western Turkey. Experiments were conducted in randomized complete block design with three replications. Five irrigation treatments (IT) were studied: 100% (IT1, control), 75% (IT2) or 50% (IT3) evapotranspiration throughout the entire irrigation season; 100% of IT1 during the first half of the irrigation season (during 45 days from plantation) and 75% (IT3) or 50% (IT4) of IT1 during the second half of the irrigation season (about 45 days). The greatest fruit yield was obtained from IT1 treatment and significant decreases were observed in fruit yields with increasing water deficits. As compared to the control, IT4 treatment offered about 15% saving in irrigation water and a low level of reduction in yield (2.11%). Relatively high irrigation water productivity and water productivity values were obtained from IT2 and IT4 treatments. Effects of DI on water potential are also reflected in leaf nutrients. Reductions in water uptake resulted in reduced nutrient uptakes. The greatest leaf nutrient contents were observed in the IT4 treatment. Except for Mn and Cu, significant decreases in leaf nutrients with increasing water deficits were observed.