2022 AlmondBeat #5: The Trees' Guide for a Successful Post-Harvest Irrigation

The AlmondBeat Post-harvest guide is here.

Here we grow!

More Than 70% Reduction In Fruit Load

Research by David A. Goldhamer & Mario Viveros from the University of California on "effects of pre-harvest irrigation cutoff durations and post-harvest water deprivation on almond tree performance" found out the following: "Depriving trees of post-harvest irrigation had a greater impact on tree productivity than the pre-harvest irrigation cutoffs, even though the amount of post-harvest-deprived water was less than that which occurred with the more severe pre-harvest cutoffs. In the season following post-harvest water deprivation, bloom density and fruit set were reduced by up to 52.2% and 94.3%, respectively. This resulted in fruit load and kernel yield reductions of up to 76.7% and 73.6%, respectively".

The researchers bottom line: post-harvest irrigation critically affects the return bloom potential for the following spring.

Now Is The Time To Invest In The Future

A common misconception is that after harvest, trees' water demand drops relatively low, allowing for some water savings potential.

Though it does drop off from its peak season highs, this is a dangerous assumption to make, and one which might have a significant influence on future yields.

A Sensitive Time What makes post-harvest a sensitive time for almond trees, is that it coincides with flower bud-differentiation which usually takes place around this time of year. The tree needs to create and store up carbohydrates to support bud-differentiation, which will directly affect next season's yields. The creation of sugar depends on photosynthesis and water availability. With less sugars available to the tree due to stress, less energy can be allocated towards flower formation.