AlmondBeat #10: Post-harvest irrigation will define 2021 yields

Your next season's yields depend on how well you maximize post-harvest through irrigation. As always, it all starts with listening to your trees.

AlmondBeat report #10, Here we go

Now is the time to invest in the future For some, post-harvest may seem to imply that the season is over and it's time for a vacation. But a farmer's job is never done, and the foundations laid during post-harvest will determine next year's yields. 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 peak season highs, this is a dangerous assumption to make, and one which might have a significant influence on productivity!

More than 70% reduction in fruit load Research by David A. Goldhamer & Mario Viveros from the University of California (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".

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 also during September. 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.

Taking the guesswork out of irrigation management

The bottom line is clear cut: You should not automatically cut irrigation during post-harvest. But since water is scarce and precious, leaving those valves open isn't an option either. That's exactly where Phytech's impact is felt.

Getting real-time readings from the trees and translating them into a visual map of each block's water demand, helps you deliver water surgically (quantity, duration, timing) to maximize growth and future productivity while also avoiding stress and saving water.

By letting you track trees' growth and status, Phytech is taking the guesswork out of post-harvest irrigation.

Maximize growth, by optimizing irrigation What the research above found is clearly seen when you look at what the trees are telling you: Although post-harvest water demand is relatively lower due to the reduction in fruit demand, trees still need water for their growth, especially with the high ETo during August-September. Does it automatically mean you need to deliver more precious water to the block? Not necessarily. In the example below, stress is avoided and positive growth is maintained by increasing frequency:

Phytech's irrigation reference and the plant status indicators help you fine-tune irrigation by giving a clear picture of the actual water demand, and the effect of irrigation on trees' growth. Are the trees' starting to slow down and is plant status shifting into the orange spectrum? Maybe it's time to increase the frequency and get them back on the growth track. Are the trees showing strong growth and weather conditions are improving? Perhaps you can take your foot off the pedal and monitor the result. The art of optimizing irrigation is never a fixed set of rules, but the ability to adapt water delivery (quantity, frequency, duration, timing) according to what the trees are communicating right now, and is crucial for future production.

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