Growth phenology and thermal accumulation patterns of yellow dragon fruit (Selenicerus magalanthus Haw.) in Indian tropics

Dragon fruit, an exotic tropical fruit, is rapidly gaining popularity in India due to its nutritional value and increasing consumer demand. Among the various species, Selenicereus megalanthus Haw. (yellow dragon fruit) stands out for its unique genetic composition (tetraploid), distinctive morphological traits and superior pulp quality. However, the phenological development of S. megalanthus has not yet been systematically characterized. Recognizing the importance of phenological studies in optimizing crop management, the present study conducted during 2022–23 at the Central Horticultural Experiment Station (CHES), ICAR-IIHR, Hirehalli, Tumkur, Karnataka-provides a detailed description of the vegetative and reproductive growth stages of yellow dragon fruit using the extended Biologische Bundesanstalt, Bundessortenamt and Chemische Industrie (BBCH) scale. While the methodology followed established BBCH frameworks, this research expanded upon prior work by incorporating additional mesostages, capturing nuanced growth variations and refining degree-day calculations. Results revealed staggered vegetative flushes, extended reproductive bud emergence and a higher cumulative degree-day requirement (817.34 DD) for fruit maturation compared to other species previously studied. By highlighting these distinct developmental patterns, the study presents an improved phenological framework that will enhance precision in agronomic management and breeding programs. The findings offer valuable insights into optimizing crop management practices specific to S. megalanthus under tropical conditions.