Assessing the Effects of Deficit Irrigation Techniques on Yield and Water Productivity of Processing Tomato

Abstract

Given the current water scarcity and aiming at sustainable agricultural development, it is necessary to identify and apply the most appropriate practices for water saving, also considering yield and water productivity improvement. Tomato is a high-water-demand vegetable crop, and excessive use of irrigation water generally leads to overexploitation of groundwater resources and deterioration of the environment. In addition, excess irrigation water leads to low water productivity (yield/water use ratio). Thus, there is an urgent need to increase crop yield with concomitant conservation of water resources. This study aimed to identify the effect of regulated deficit irrigation on the yield and water productivity of tomato cultivar N-901 for industrialization purposes. Deficit irrigation was carried out during the vegetative growth stage, considering different seedling transplanting periods. The experiment was conducted in a greenhouse at the School of Agronomy of the Federal University of Goiás (UFG). The experimental design was a randomized complete block with five replicates, in a 2 x 4 factorial arrangement. The plots were made by combining two periods of irrigation deficit (10 and 20 days after transplanting - DAT) and four soil water tension thresholds (30; 40; 60; and 70 kPa). The results showed that the studied cultivar responded significantly to the water deficit, providing different agronomic development profiles. The tensions of 30 and 60 kPa applied at 10 DAT were the ones that most intensified yield and water productivity without significantly affecting the agronomic development of the crop. Deficit irrigation at 60 kPa was shown to reduce the total volume of water applied during the cycle without significantly reducing crop production compared to the tension of 30 kPa. Keywords: irrigation strategy, limited irrigation, water saving, morphology and physiology.