Enhancing sugar levels in winter-grown watermelon through strategic pruning: Sweetness beyond seasons

The study aimed to enhance the sweetness and fruit quality of winter-grown watermelon by evaluating the effects of distinct pruning methods on growth, yield and physiological and biochemical characteristics. The treatments were control, single stem pruning, double-stem pruning and fruit thinning, which were investigated during 2 consecutive winter seasons under pot and field conditions. Single stem pruning at 35 days after sowing showed the most pronounced improvement among all the tested treatments. This treatment strongly enhanced TSS (9.28 °Brix in pot-grown plants and 8.82 °Brix in field-grown plants) and increased reducing, non-reducing and total sugars compared with the other treatments. Sweetness enhancement is coupled with increased chlorophyll content, enhanced antioxidant enzyme activities and higher accumulation of primary and secondary nutrients in the fruit pulp. Fruit thinning greatly improved external colour; however, single stem pruning was superior in enhancing the internal quality and overall marketability of the fruits. The results indicate that single stem pruning is an effective management practice for increasing sweetness, physiological performance and yield of winter-grown watermelon under off-season production conditions.