INFLUENCE OF THE CROP WATER STATUS ON FRUIT SETTING AND FINAL FRUIT NUMBER IN A PROCESSING TOMATO CROP

The effects of crop water status on fruit setting and final fruit number of processing tomatoes were investigated in a sandy loam soil in Extremadura (Western Spain). Three irrigation treatments of 50, 90 and 130% of the crop evapotranspiration (ETc) were applied (R1 = 0.5 ETc, R2 = 0.9 ETc, R3 = 1.3 ETc). Canopy temperatures (Tc) were different in the three treatments along the season. The fruit setting was highly sensitive to water stress: fruit set was higher in R3 than in R2 and R1 and similar between R2 and R1. The highest differences among treatments in the fruit set occurred during the peak of fruit setting, between the day 10th and 30th after the first fruit set. The fruit setting next to harvest was also higher in the R3 treatment. Whereas differences in fruit setting where found among treatments, the total final fruit number (green, red and overripen) was similar in all the treatments. On the other hand the number of red fruits was lower in R₁, compared to R₂ and R₃ and similar between R₂ and R₃.