IMPROVEMENT OF GREENHOUSE TOMATO FRUIT QUALITY BY MANIPULATION OF ROOT SIZE, NUTRIENT SOLUTION COMPOSITION, AND FRUIT THINNING

摘要

Fruit quality is a crucial factor in the production of greenhouse tomatoes Impaired fruit quality such as smaller fruit in the upper trusses, blotchy ripening and blossom end rot (BER) are common tomato fiuit disorders in Israel. The objective of thisstudy was to improve fruit quality of greenhouse tomato by agrotechnical methods; root pruning and restriction in combination with variations of N-NO_3, K and Ca solution concentrations, and fruit thinning. Although root pruning reduced shoot growth, fruit yield, and average fruit weight, it increased the percentage of fruits free of internal and external blotchy ripening Root restriction increased total soluble sugars (TSS) in the fruit and decreased the percentage of fruit affected by BER Increasingthe nutrient solution concentration of K from 2.5 to 10 mM increased the occurrence of BER, whereas increasing Ca concentration from 3 to 7 mM reduced it. Root restriction decreased K concentration in the leaves and fruit. Increasing NO_3 solution concentration from 1 to 9 rnM did not compensate for the pruned or restricted roots reduction sin tomato yield, alter either TSS content or the occurrence of blotchy ripening, but did increase the incidence of BER. Thinning to four fruits per truss reduced fruit yield by 40%, but increased the average fruit weight of the trusses above the fourth truss by 50%.