Effects of managed pollination by stingless bee (Tetragonula iridipennis Smith) on productivity and fruit quality of sponge gourd (Luffa cylindrica)

Pollination is a critical ecosystem service that directly influences fruit set, yield and quality in cucurbit crops. The present study evaluated the pollination efficiency of the stingless bee, Tetragonula iridipennis Smith, in sponge gourd (Luffa cylindrica) under protected cultivation conditions at the experimental farm of AICRP on Honeybees and Pollinators, Nagaland. Floral biology observations revealed that sponge gourd is monoecious and protandrous, with peak anthesis occurring between 0500 and 0700 h and stigma receptivity lasting up to 9 hours. A diverse assemblage of pollinators was recorded, among which stingless bees were the most dominant visitors. Pollinator abundance was highest during the morning hours, particularly between 0800 and 1000 h, indicating optimal conditions for pollination activity. Managed pollination using T iridipennis significantly enhanced fruit yield and quality compared to open pollination and pollinator exclusion treatments. The highest fruit yield (3.68 ± 0.11 kg/ plant), fruit length (25.60 ± 0.14 cm), fruit diameter (7.83 ± 0.09 cm) and fruit weight (0.621 ± 0.11 kg) were recorded under stingless bee pollination. This treatment also resulted in the lowest percentage of crooked fruits (9%), highest number of healthy fruits (91%), maximum seed number per fruit (214 ± 21) and highest 100-seed weight (150.14 g). In contrast, pollinator exclusion significantly reduced yield and fruit quality. The findings demonstrate that T iridipennis is an efficient and reliable pollinator for sponge gourd under protected conditions and offers a sustainable alternative to manual pollination for improving crop productivity and fruit quality.