Responses of some local tomato genotypes to water deficit

This study was conducted to determine the effects of irrigation programs on some local tomato genotypes under unheated greenhouse conditions. For this purpose 17 tomato genotypes collected from different provinces of Turkey and one commercial hybrid cultivar (‘Lapçin’) were tested in an open soilless system. Perlite was used as the growing medium as 9 L plant^‑1. Three irrigation treatments based on indoor integrated solar radiation of 1, 2 and 4 MJ m^‑2 were used to trigger irrigation. Irrigation was started automatically by the GP1 data logger-control unit and the amount of nutrient solution was adjusted according to the ratio of drain water to the applied volume. Marketable yield and some fruit quality parameters were measured, and irrigation water use efficiency (IWUE) and water use efficiency (WUE) was calculated. The highest marketable yield, IWUE and WUE was obtained from 1 MJ m^‑2, however, the response of genotypes showed difference. Marketable yield, average fruit weight, IWUE and WUE decreased with decreasing amount of water applied. Fruit quality parameters were affected by genotypes and irrigation treatments. The dry weight, titratable acidity, total soluble solids and EC of fruit juice increased under water deficit compared with control. It was concluded that yield, IWUE and WUE were affected negatively and decreased with decreasing amount of water applied in the irrigation programs based on the integrated indoor solar radiation level. However IWUE and WUE values of some genotypes (such as 26, 60, 67, 79) in 2 and 4 MJ m^‑2 were found promising for further breeding researches.