INFLUENCE OF PRE-HARVEST SALICYLIC AND SOME AMINO ACIDS TREATMENTS ON QUALITY ATTRIBUTES OF PEAR FRUITS CV. LE-CONTE DURING COLD STORAGE AND SHELF LIFE

Abstract

This study aimed to determine the relationship between preharvest treatments by salicylic acid, Larginine and L-tryptophan with fruit quality of pear cv. Le-Conte during cold storage at 0◦C and 9095% RH for 12 weeks followed by shelf life at 22◦C for 12 days. Treatments included L-arginine at 100 and 200 ppm, L-tryptophan at 50 and 100 ppm, salicylic acid at 100 and 200 ppm and water as control, all treatments were sprayed on mature trees until run off twice; at full bloom stage and at initial fruit set stage. All conducted treatments were effective in maintaining fruit quality compared with control. Tryptophan at 100 ppm showed the highest significant TSS values, while salicylic acid at 200 ppm showed the lowest significant TSS values during cold storage and shelf life circumstances. Salicylic acid at 100 and 200 ppm showed the lowest weight loss percentages, salicylic at 200 ppm decreased the rate of decay incidence, showed the lowest significant respiration rates, also it was effective in alleviating core browning. In addition, salicylic acid at 200 ppm significantly maintained firmness of fruits, and showed higher h° value of fruits peel, ascorbic acid concentrations, total phenols content and antioxidant capacity values of LeConte pear fruits. Preharvest treatments by salicylic acid, L-arginine and L-tryptophan positively influenced postharvest fruit quality, salicylic acid at 200 ppm effectively maintained fruit quality during cold storage and shelf life.