Floral and pollination biology of dragon fruit reveals strategies for enhancing productivity through pollination management and reproductive window extension

Dragon fruit (Selenicereus undatus (Haw.) D.R. Hunt) is emerging as a high-value crop globally. However, its reproductive biology remains poorly characterized, with conflicting reports ranging from strict self-incompatibility (allogamy) to self-compatible and autogamy. This study presents a comprehensive two-year assessment (2023 and 2024) of reproductive phenology, pollination modes, and floral biology of commercially grown white-fleshed variety (NDFW-1) that belongs to S. undatus (Haw.) D.R. Hunt, under subtropical Indian conditions. Flowering exhibited inter-annual variation linked to early summer rains, which acted as floral inducers-highlighting the potential of microclimate manipulation (fogging, sprinklers, rain guns) to extend the reproductive window. Although the white fleshed variety (NDFW-1) was self-compatible, manual cross-pollination significantly enhanced fruit weight, indicating limitations in natural pollination. In contrast, the red fleshed variety (NDFR-1) clone exhibited strict self-incompatibility, necessitating cross-pollination for fruit set. Anthesis dynamics and post-anthesis floral bending suggest mechanisms of delayed autogamy but are insufficient for achieving commercial-grade fruit. Pollen viability and stigma receptivity data identified a well-synchronized broader pollination window from 4 h before to 12 h after anthesis. These findings advocate precise, time-targeted pollination preferably early evening or morning hours to improve fruit set and size, particularly under rain-induced pollination deficit, and offer a validated framework for optimizing dragon fruit production in emerging regions.