Photothermal sensitivity, adaptability and nutritional profiling of winged bean (Psophocarpus tetragonolobus (L.) DC.)

Abstract The present study evaluated ten winged bean genotypes across eight environments comprising three locations, Bhubaneswar, Bengaluru and Chettalli, to assess environmental effects, genotype × environment (G × E) interactions, adaptability and nutritional quality. Significant G × E interaction variances were observed for pods per plant, pod yield per plant and tuber yield per plant. Flowering and pod set were highly environment-dependent, and no flowering and fruiting occurred during the spring–summer (SS) seasons at Bhubaneswar. The daily average temperature (29.9 °C) and Photo Thermal Units (PTU) (22,477 °C day h) were identified as maximum threshold limits for flowering in winged bean. Pods per plant (600.6 in 2024 and 574.4 in 2025) and pod yield per plant (8662.5 and 9020.5 g) were high under the Bengaluru summer–rainy (SR) environments. High temperatures and high PTUs had suppressed pod production in Bhubaneswar-SS environments. In contrast, low pod numbers in Autumn-Winters (AW) of Bhubaneswar and Chettalli could be attributed to low daily minimum temperatures. Tuber production was highest in Chettalli-AW-2025 (256.82 g plant −1 ), whereas negligible yields were recorded under the Bhubaneswar spring–summer seasons (0.06–0.54 g plant −1 ). Cumulative Diurnal Variation in Temperature and short days had a positive effect on tuber yield per plant. BLUP and WASSB analysis identified IIHR-WB-07 as the highest-yielding genotype, with fairly stable pods per plant, pod yield per plant and tuber yield per plant across the growing seasons. Nutritional profiling showed considerable variation among genotypes, with pod ascorbic acid ranging from 0.43–0.74 mg 100 mg −1 DW, seed protein from 16.11–25.73 mg 100 mg −1 DW, and tuber carbohydrate from 8.78–29.77 mg 100 mg −1 DW. The study identified superior genotypes, such as IIHR-WB-07, and demonstrated the influence of the environment on flowering, pod production, and tuberization in winged bean.