Effect of Regulated Deficit Irrigation on Growth Characteristics, Fruit Yield and Quality of Japanese Plum (Prunus salicina Lindell cv. Friar)

Deficit irrigation is one of the effective methods for increasing water use efficiency in fruit orchards under arid and semiarid climates. In this study, the effects of deficit irrigation (50 and 75% ETc) during pit hardening and after harvest on growth characteristics and fruits yield and quality of Japanese plum trees cv. Friar were studied during two consecutive years. The results showed deficit irrigation reduced the number of nodes as well as the length of nodes and shoots. However, the effect of deficit irrigation on reducing shoot length was significantly high, when applied after fruits harvest. Flowering density and fruit set percentage in the following year were not affected by RDI. Total fruit yield and acceptable fruits of 50 ETc was significantly lower than control, but no significant difference was found for control and 75% ETc. Deficit irrigation have no significant impact on fruit dry matter but fruit firmness of 75% ETc (2.3 kg/cm2) at the end of the storage was significantly higher than 50% and control (1.2 and 1.85 kg/cm2). The lowest SSC and TA were found in fruits at the end of the storage when irrigated with 50% ETc. Overall, irrigation with 75 ETc is recommended because of saving water and without negative effect on fruit yield.