EXOGENOUS APPLICATION OF ABSCISIC ACID BY FOLIAR SPRAYING ON FICUS CARICA L.: ON-TREE RIPENING MONITORING UNTIL COMMERCIAL HARVEST

Presentación de poster en VI Simposio Internacional de Granada y Frutos Menores del MediterráneoExogenous application of abscisic acid by foliar spraying on Ficus carica L.: ontree ripening monitoring until commercial harvestAbstractFigs are an infructescence called a syconium, known for their appetising taste and high nutritional value. Their development and growth are divided into three phases, and ripening is a dual mechanism depending on abscisic acid (ABA) (non-climacteric part) and ethylene (climacteric part). In addition, figs have the disadvantage of not ripening simultaneously on the same shoot, which makes harvesting difficult. ABA has been extensively documented to affect ethylene production, ripening, and senescence processes. Moreover, it can stimulate adaptive responses to abiotic stress. On-tree ABA application in figs via the ostiole has been shown to stimulate growth and homogenise fruit ripening, thus facilitating harvesting. Therefore, this work aimed to study the effect of exogenous applications of ABA on fig ripening. For this purpose, during the 2024 season, under super-intensive conditions, two and three ABA applications (one per week) in two concentrations (2.27 and 2.84 mM) were carried out via foliar application on the ‘Calabacita’ cultivar once most fruits had physiological maturity. Fruits were monitored for colour, size, and chlorophyll index as they ripened on the tree. It was observed that ABA treatments improved colour, obtaining tones more associated with ripe fruit. In addition, fruit size increased with both treatments, especially ABA 2.27 mm. Fruits were also analysed after treatment with 2 or 3 applications at commercial harvest. In general, fruits that received two applications of ABA were less ripe, greener in colour, firmer, and had higher moisture content and titratable acidity. On the other hand, fruits with three applications showed a higher ripening index.Treatment-related variations in colour characteristics were noted in comparison to the control batch. Treated fruits also had lower firmness but a higher weight, size, and chlorophyll index. Consequently, ABA exhibits promising results as a preharvest treatment to modulate fig fruit ripening.Keywords: Preharvest treatment; on-tree monitoring; fruit maturity; DA-meter; fruit quality