Growth, Yield, and Fruit Quality of Two Hydroponic Melon Cultivars under Varying Topping Management
Abstract
Melon (Cucumis melo L.) is an economically important horticultural crop in Indonesia, and its growth, yield, and fruit quality are strongly influenced by the balance between vegetative and reproductive growth. Excessive vegetative growth after fruit set can reduce fruit size and quality by competing with developing fruits for assimilates. Topping to regulate the number of leaves retained above the fruit may improve fruit development; however, information regarding the appropriate leaf retention level under hydroponic conditions remains limited, particularly for cultivars with contrasting leaf morphologies. [EA1.1][L1.2]This study evaluated whether broad- and narrow-leaf hydroponic melon cultivars respond differently to leaf retention level and identified a practical topping strategy for hydroponic melon production. Two cultivars, Sweet Hami (broad-leaf) and Dalmatian (narrow-leaf), were grown using a Dynamic Root Floating Technique (DRFT) system and subjected to four topping levels equivalent to retaining 8, 12, 16, and 20 leaves above the fruit. Sweet Hami showed a stronger response to leaf retention in terms of leaf area development and fruit weight, while Dalmatian exhibited a more gradual response. Retaining 16 leaves above the fruit resulted in favorable fruit weight and total soluble solids without excessive vegetative growth in both cultivars. These findings suggest that topping at the 17th internode may serve as a practical shoot management strategy for improving yield and fruit quality, while providing a useful reference for optimizing source-sink balance in hydroponic melon production across cultivars with different leaf morphologies.