PREHARVEST IRRIGATION CUTOFFS DURING STAGE II INCREASES WATER SAVINGS AND PROFITS IN 'ALGERIE' LOQUAT
The price of loquat fruit depends on earliness and size. The imposition of a regulated deficit irrigation (DI) after harvest is a profitable strategy for producing loquats due to its effects on promoting earlier flowering and harvest for the next season. In the optimization of this postharvest DI strategy, a shortening of the deficit irrigation period has led to greater harvesting advancement and profitability, but lesser water savings. Aiming to increase the water savings and to improve even more fruit earliness and quality, we have now explored Algerie loquat response to five treatments, some of them combining pre- and postharvest deficit irrigation: T1, postharvest DI during eight weeks in June-July; T2, same postharvest DI plus no irrigation for twelve weeks from rapid fruit growth to harvest; T3, postharvest DI plus no irrigation for seven weeks in the period from color break to harvest; T2-3, postharvest DI plus seven weeks of DI from rapid fruit growth to color break, when we reestablished the irrigation until harvest. A control treatment of fully irrigated trees along the season was also established. Water savings differed among treatments resulting greatly increased by the adoption of a preharvest period of DI. T2 saved more water than the other DI treatments (46% less irrigation than controls). Both, T3 and T2-3 treatments, allowed 37% less of watering in comparison to controls. T1 saved 26% of water respect to controls. The single sigmoid curve described for loquat fruit growth was unmodified by watering restriction. Fruit growth rates were not significantly diminished by preharvest DI. Fruit size at harvest was not reduced either, perhaps because rainfall during DI prevented severe water stresses. Finally, pre¬harvest DI failed to further increase fruit earliness, since the harvest advancement (between 9-11 days) was only due to the effects of an early bloom produced by post-harvest DI (T1). T2-3 treatment increased the most water productivity (WP) and water use efficiency (WUE). These results have to be verified in drier seasons.
Stellfeldt , A., Cuevas , J. and Hueso, J.J. (2011). PREHARVEST IRRIGATION CUTOFFS DURING STAGE II INCREASES WATER SAVINGS AND PROFITS IN 'ALGERIE' LOQUAT. Acta Hortic. 922, 303-309
Eriobotrya japonica, regulated deficit irrigation, water stress, reproductive phenology