Effects of a temporary water and nitrogen deficit in the soil on tomato yield and quality.

The effects of temporary water and nitrogen stress were investigated on tomato plant (Lycopersicon esculentum Mill) in a field experiment carried out in Southern Italy. The plants were stressed at different times during the cropping cycle; at 0, 50, and 100% flowering in the control treatment. Leaf area index, and the fresh and dry weights of tomato plants were determined at maximum development. In addition, total nitrogen and nitrate concentrations in stems, leaves and fruits were determined at the intermediate and final harvests. The results indicated that temporary stresses for water and nitrogen have significant influences on leaf area index, and the fresh and dry weights of tomato plants. Temporary stresses influenced nitrate accumulation by the intermediate harvest only, but did not influence nitrate content in the plant at the end of cropping cycle. On the other hand, total nitrogen and nitrate concentration behaved differently in the several different tissues (leaves, stems and fruits). This is evidence that water and nitrogen stresses influence plant development and nitrogen dynamics in tomato cropped in Southern Italy. [ABSTRACT FROM AUTHOR]