Optimal dates for regulated deficit irrigation in ‘Algerie’ loquat (Eriobotrya japonica Lindl.) cultivated in Southeast Spain

To select the optimal period for regulated deficit irrigation (RDI) in ‘Algerie’ loquat, three RDI treatments incorporating a reduction of 66% (first season) or 75% (second season) of the water requirements either in June, July or August were compared with fully irrigated trees. RDI during June and July advanced flowering in both seasons. RDI during August had negligible effects or delayed bloom date, depending on the season. Earlier blooming led to an earlier harvest, which in turn improved fruit value. All RDI treatments produced greater bloom. RDI during August, especially with larger water savings, impaired flower development. Fruit set, size and yield did not change among treatments, despite the negative effects caused by RDI during August on the size of the flowers. July has been selected for ongoing research as the most promising date for RDI in ‘Algerie’ loquat due to its greater effects on the advancement of bloom and harvest date and its harmlessness for flower development.