REGULATED DEFICIT IRRIGATION OF 'ROJO BRILLANTE' PERSIMMON (DYOSPYROS KAKI) YIELD, FRUIT QUALITY AND POST-HARVEST PERFORMANCE
Persimmon (Diospyros kaki) culture is gaining importance as a temperate fruit crop in the Mediterranean area. The main persimmon cultivar grown in Spain is Rojo Brillante, which produces an astringent fruit. This implies the need of a deastringency post-harvest treatment prior commercialization. Persimmon culture in Spain is concentrated in an area of water scarcity, but there is no information about tree water needs nor responses to deficit irrigation. With this in mind, an experiment was conducted over three consecutive seasons in order to determine yield responses to water restrictions applied during different stages of fruit growth. Moreover, the effects of timing of deficit irrigation on fruit quality at harvest and on the effectiveness of a postharvest deastringency treatment were evaluated. Four irrigation treatments were applied including watering at 100% of the estimated tree evapotranspiration (ETc) during the entire season, and other three treatments where irrigation inputs were reduced at 50% ETc only during certain periods (spring, summer or fall). In all three seasons, water deficit, when applied during spring, reduced June fruit drop. This effect could be either positive or negative depending on the tree crop level and the grower´s final fruit size target. However, water restrictions regardless of the period when they were applied, significantly affected (up to 22% reduction) fruit weight at harvest suggesting high sensitivity of Kaki trees to water stress. Fruit ripening was accelerated when water restriction were applied during fall; this is reflected in a higher external color and lower firmness of the fruit at harvest maintaining high quality. None of the deficit irrigation treatments affected the effectiveness of deastringency treatment with high CO2 concentration. It is concluded that, despite Diospyros kaki being a crop sensitive to water stress, deficit irrigation can still be used as a measure for increasing tree crop level and accelerating fruit ripening.
Intrigliolo, D.S., Bonet , L., Badal, E., Besada , C. and Salvador, A. (2014). REGULATED DEFICIT IRRIGATION OF 'ROJO BRILLANTE' PERSIMMON (DYOSPYROS KAKI) YIELD, FRUIT QUALITY AND POST-HARVEST PERFORMANCE. Acta Hortic. 1038, 415-422
astringency, color index, fruit growth, water relations, water use efficiency