Plant Growth Regulators Applied During Cultivation and Their Impacts on the Postharvest Quality of Tropical Fruit Crops: A Review

Tropical fruit crops are of high economic, social, and nutritional importance. However, the high perishability of these fruits, characterized by accelerated metabolism and sensitivity to ethylene, results in significant losses during storage, transportation, and commercialization. In this context, plant growth regulators (PGRs) have gained prominence not only for their role in agronomic field management but also for their potential to modulate postharvest quality attributes. This review critically examines whether plant growth regulators applied during cultivation influence postharvest effects in tropical fruit crops, highlighting the main mechanisms involved, possible interactions between regulators and other molecules, and existing gaps in the literature. The synthesis indicates that plant growth regulators applied in the field have high potential to improve fruit development, delay ripening, enhance physicochemical attributes, and reduce the incidence of physiological disorders. However, most studies focus their evaluations at harvest, without monitoring the effects of PGRs throughout storage, transportation, and commercialization. Methodological gaps are therefore evident, reinforcing the need for more integrated and long‐term studies capable of elucidating the real impact of PGRs on the postharvest conservation of tropical fruits. Moreover, there remains a scarcity of information on potential synergies between PGRs and other preservation technologies, as well as a lack of clarity regarding the origin of the observed effects, whether they result from direct residual action of the regulators or from indirect effects associated with physiological and morphological changes in the plant, such as enhanced root development or alterations in nutrition, which subsequently influence fruit quality. These aspects point to relevant and still underexplored opportunities for future research.