Phenological Development and Shoot Growth of Calamansi (Citrus x microcarpa) Under Pruning and Waterlogging Conditions in a Tropical Agroforestry Context

Abstract

This study investigated the shoot growth and phenological development of containerized grafted calamansi (Citrus × microcarpa) seedlings under three cultivation treatments: control, waterlogging, and pruning. Conducted in the Philippines, a tropical country where calamansi is a high-value fruit crop, the experiment aimed to evaluate how abiotic stress and canopy management influence plant development. Using the BBCH scale for standardized phenological monitoring, the plant growth parameters such as the height, shoot length, and number of leaves were measured biweekly over a 54-day observation period. Results showed that pruned seedlings significantly exhibited enhanced vegetative growth, while waterlogged seedlings progressed more rapidly to reproductive stages. Control plants followed a moderate developmental trajectory. Early flowering and fruiting under waterlogging appeared to be a stress-induced survival response, whereas pruning delayed phenological progression but promoted vigorous vegetative growth. These findings highlight the potential of pruning as a management tool for off-season calamansi production and underscore the detrimental long-term effects of waterlogging. Overall, the study demonstrates the importance of phenological monitoring in guiding orchard management practices to improve crop resilience and productivity in tropical agroforestry systems.