Influence of the main stem pruning and fruit thinning on quality of melon

ABSTRACT Among many management practices used in melon crops, those that change source: sink relationship, such as pruning and fruit thinning, directly influence production, affect fruit size and its composition, including sugar and vitamin contents. The objective of this study was to evaluate the influence of pruning of the main stem and time of fruit thinning in melon postharvest quality. Thus, two experiments were set up in Mossoró, state of Rio Grande do Norte, each with a melon hybrid (Amaregal and Banzai). Each experiment was conducted in a randomized block, in a (2 x 4) + 1 factorial design, 2 pruning management (with and without pruning), 4 levels of fruit thinning (3, 6, 9 and 12 DARB - days after removal agro textile blanket) and a control (without pruning and thinning), and four replications. Fruits were harvested at commercial maturity and transported to the Laboratory of Food Technology of UFERSA, where they were evaluated for the following characteristics: weight, diameter, length, flesh thickness, flesh firmness, soluble solids, pH, and titratable acidity, soluble solids: titratable acidity ratio and vitamin C. No interaction between factors in any of the experiments was found. Titratable acidity (0.077%) and vitamin C content (3.4 mg/100 g) in Amaregal melon and soluble solids (10.2%) in Banzai melon were lower in the treatments with stem pruning. In Amaregal melon, fruits showed longer length (134 mm) and greater flesh firmness (40 N) when thinning was carried out on 6 DARB, and as thinning was delayed, it found a decrease in the values of soluble solids, SS: TA ratio and pH. In Banzai melon, fruits showed greater flesh thickness (33.5 mm) and SS: TA (247.5) ratio when thinning was carried out on 6 DARB. However, delay in thinning promoted an increase in pH and vitamin C content of the fruits. Pruning of the main stem and thinning season had effect on the quality of Amaregal and Banzai melons in different ways.