Postharvest regulated deficit irrigation in early- and intermediate-maturing loquat trees

Postharvest deficit irrigation (DI) strategies have been proven to advance bloom, harvest dates and economic return in loquat 'Algerie' trees because an early harvest results in higher loquat fruit prices. This fact poses the question of whether postharvest DI strategies could have a similar effect on more precocious cultivars than cv. Algerie, providing thus a more profitable option to farmers. In this work, the response of an early- and intermediate-maturing loquat cultivars (cv. Cardona and Algerie, respectively) to a summer early (DIearly) and late (DIlate) DI strategy was assessed in two parallel studies during three consecutive years. The effects of the DIearly and DIlate strategies on bloom date, percentage of fruit picked at harvest per picking date and yield of both loquat varieties were studied. Moreover, fruit quality of cv. Cardona at harvest was also assessed. Plant water status was monitored by midday stem water potential (Ψstem) measurements. Results showed that DIearly and DIlate strategies advanced bloom in both cultivars although a higher effect was observed with the DIearly than with the DIlate treatment. Water restrictions did not increase the percentage of fruit picked at any of the picking dates and did not affect yield or fruit quality in the early-maturing cultivar. In 'Algerie' trees, a higher percentage of fruit was generally picked during the first picking dates in the DIearly and DIlate treatments than in the control although differences were only statistically significant during the last experimental season. Yield was significantly higher in 'Algerie' DIlate trees than in control or DIearly trees two out of the three experimental seasons. Overall, results showed that the DIearly and DIlate strategies tested here did advance bloom in the early-maturing cultivar but did not have an effect on the percentage of fruit picked per picking date at harvest. Nevertheless, the fact that substantial water savings (>30%) were obtained with no detrimental effect on yield presents the use of postharvest DI strategies as an interesting option to be followed in early-maturing cultivars for a more efficient crop production.