Regulated deficit irrigation (RDI) can be used as an effective strategy for increasing water use efficiency (WUE) under arid and semiarid climate. Therefore, in this study the effect of RDI (50 and 75% evapotranspiration of a crop under irrigation (ET_C)) as compared to control during pit hardening and after fruit harvest on vegetative growth, fruit yield and quality of Japanese plum 'Methly' was investigated during two consecutive years. The results showed that water available limitation in RDI 50% both during pit hardening and after fruit harvest significantly reduced shoot growth. RDI treatment during postharvest decreased both node number and internode length. The highest flowering rate and fruit set percentage was found when plum tree was irrigated 75% ETC during pit hardening in both years. In the first year, RDI decreased fruit yield, whereas, in the second year, RDI 75% during pit hardening even increased slightly fruit yields for 6 and 11% as compared to control and postharvest stage, respectively. Fruit weight was significantly reduced under RDI 50%. Fruit produced under 50% RDI showed higher firmness and lower soluble solids concentration (SSC) and titratable acidity (TA) than control and other treatment. Furthermore, RDI treated fruits had lower N, P, Mg content and N/Ca and Mg/Ca ratio and higher Ca content than control. Overall, moderate water stress (75% RDI) improved fruit yield and saved water without undesirable effect on plum fruit quality.

firmness, nutrient elements, pit hardening, vegetative growth and fruit quality

Published by University of Zagreb, Faculty of Agriculture, Zagreb, CROATIA
Sponsored by Ministry Science and Education of the Republic of Croatia