The timing, duration and intensity of olive tree water restrictions during summer differentially influence olive growth and production, based on fruit development processes.
For this, the morphogenetic response of tissues to different irrigation strategies during summer were examined in a Spanish olive grove.
Control (CON) trees were irrigated to maintain the root zone near field capacity during fruit growth.
From budbreak to 4 weeks after full bloom (WAFB) (Period 1) and from 14 WAFB to harvest (at 23 WAFB) (Period 4) trees in all treatments were watered at the control level.
Two severe water deficit treatments were applied during summer by irrigating 30% CON 4 to 9 WAFB (Period 2) in DI-P2 or 9 to 14 WAFB (Period 3) in DI-P3.
Moderate water deficit was applied in periods 2 and 3 by irrigating at 50% in DI-P2 and 3.
The growth and development of the fruit and its component tissues (exocarp – peel, mesocarp – pulp and endocarp – stone), the composition of the olives, the cell area of the mesocarp and the cell number and the characteristics of the cells were evaluated. were measured at the end of each period.
Water deficits significantly reduced olive volume at the time they were applied.
Pulp size was more sensitive to water deficit than endocarp size and showed high resilience after irrigation.
Although most cells were developed in period 1, a considerable number of mesocarp cells formed later. While pulp cell number was not affected by water reduction in any of the deficit periods, cell size was strongly affected, but with high recoverability.
Endocarp size was reduced when water restriction was applied in DI-P2 and its effect continued until harvest.
The oil content of the olives at harvest was not significantly affected by the applied water restrictions. The thickness of the skin, the size of the oil-containing cells and their number at harvest appear to respond to both the irrigation regime and the expansion pressures of the olives.
Of RT
