Antioxidant activities, dietary nutrients, and yield potential of bitter gourd ( L.) lines in diverse growing environments.

The biotic and abiotic stresses cause a significant decline in the yield and fruit quality traits, including antioxidants and minerals, of bitter gourd when grown in open fields. Protected cultivation technology has emerged to minimize such stresses. We investigated the effect of diverse environments (hi-tech greenhouse, naturally ventilated polyhouse, insect-proof net-house, and open field) and breeding lines on earliness, yield potential, antioxidant activities, and dietary nutrients. In the GYT analysis, 12 treatment combinations involving four growing environments and three breeding lines of bitter gourd were examined. The 3-year study suggested that the cultivation of bitter gourd crops in an insect-proof net house (NH) showed superior performance in earliness, yield-attributing traits, antioxidant activities, and dietary nutrients, followed by a naturally ventilated polyhouse (NP). However, NH was on par with NP and significantly better than the open-field-grown crop. The GYT biplot analysis highlighted that the combinations of NH and Pusa Rasdar outperformed and were the most stable treatments for all the traits investigated, followed by NH in conjunction with S32 and S57 lines. This study suggests that growing bitter gourd in protected environments is the optimal strategy to achieve early market prices and improve the yield and nutritional quality of the fruits.