The effect of water deficits during the postharvest season is substantially influenced by preharvest conditions, particularly by how much water trees received during the preharvest period, and how much water is applied the rest of the season.
Flower bud differentiation continues until mid-September, which means that next year’s bloom and the following crop are formed in the middle of this year’s harvest. Severe moisture stress during bud differentiation should be avoided to protect the fruit set of the following season.
Growers on a limited water budget should optimize irrigation at critical stages, such as during bud differentiation, rather than irrigate with frequent small doses. This will minimize surface evaporation losses. A properly maintained irrigation system that operates with maximum efficiency is critical to minimize water losses.
During postharvest irrigation, it is important to keep the leaves active and functioning until normal leaf drop, which usually happens in mid-November. This prevents premature defoliation and allows the tree to transition its nutrients from the leaves to the fruiting spurs.
If the orchard prematurely defoliates due to lack of water, irrigate to encourage re-growth. This may reduce yields in the following year, but yield loss will be minimal compared to not watering at all. If watering does not occur, the fruit bud differentiation will be poor and the orchard will suffer from premature flower drop in late winter.
Water Irrigation Management
Water Quality Laws & Regulations