Long-term effects of irrigation regime on fruit development pattern of the late-maturing 'Angeleno' Japanese plum

摘要

A regulated deficit irrigation (RDI) strategy can be used to ensure efficient water use in fruit orchards under different agro-ecological conditions. However, adapting RDI to specific crop conditions is essential for its successful implementation. To date, very few studies have provided information on its long-term effects. This paper presents an 8 year study assessing the fruit development pattern of Japanese plum cv. 'Angeleno' under two different water regimes: a control (C) treatment with crop evapotranspiration (ETc) replacement, and an RDI treatment which had no irrigation in the middle of the fruit growth stage. This unirrigated period was executed for 60 days from 2009 to 2012 and for 30 days from 2013 to 2016; a 30% reduction in ETc was also applied during the post-harvest period in both cases. The results obtained in this study allowed characterisation of the fruit growth pattern of this cultivar under non-water stress conditions and an assessment of the effects of the duration and severity of water stress on the fruit. The swiftness and intensity of the water stress were crucial factors in terms of final fruit size, whereas precise determination of the initiation of RDI played only a secondary role. After eight years applying these RDI strategies, no carry-over effects on orchard yield were observed. Based on these results, RDI appears to be a sustainable practice for this cultivar and growing conditions.