Effect of irrigation regime and application of kaolin on yield, quality and water use efficiency of tomato

Modern agriculture is faced with two tasks: (1) to produce enough food for a growing global population, and (2) to ensure satisfactory crop quality while using water resources efficiently. A study of the effect of kaolin on the yield, quality and water use efficiency of tomato (Lycopersicon esculentum Mill.), grown under different irrigation regimes, is reported in the paper. The research was conducted in an open field with carbonate chernozem soil, at Stara Pazova (40 km north of Belgrade, Serbia). It lasted for three years (2011, 2012, and 2013). The experimental setup was a two-factorial, completely random block system, with three replications. The first factor was the irrigation regime and the second the application of kaolin. Two irrigation treatments were studied: (a) full irrigation (F), covering 100% of ETc (crop evapotranspiration), and (b) deficit irrigation (D) at 50% of ETc. The kaolin treatments were: (a) control treatment, without kaolin (C) and treatment with a 5% suspension of kaolin (K). On average, the highest fresh tomato fruit yields were achieved under full irrigation, with kaolin (FK) (21.0 kg m(-2)). The FK treatment also resulted in the greatest dry weight of the fruits (1.1 kg m(-2)). The average fruit weight was rather uniform and ranged from 71.7 g with DC to 75.4 g with DK. The average sugar and lycopene content was quite uniform over the study period, while the irrigation regime had a significant effect on the average organic acid content and total antioxidant activity. Deficit irrigation treatments resulted in a higher organic acid content and higher total antioxidant activity than full irrigation. The application of kaolin had a greater effect of the water use efficiency of tomato than the irrigation treatment