By Travis Goldman
Irrigation Management Advisor
Irrigation scheduling in late spring can be challenging, but there has been a pattern to balance cultural practices and applying water to almond orchards.
With this year’s below-average nut sets in some regions it has become even more important to save the remaining crop and strive for size and quality. My biggest point to customers has been to minimize high tension stress as we go through drying fields for mowing and spraying. With proper irrigation timing we can push cell expansion and maintain size without rutting up our fields and compacting our soils.
In the San Joaquin Valley, we are reaching that time where traps are getting to counts that require an insecticide application. To combat potential damage to our orchards, spring sprays for peach twig borer and navel orangeworm will be applied. Due to the weight of our tractors and tanks we must dry down the orchards to prevent rutting and compaction. Additional time is also needed for reentry before any employee can enter the orchard to turn valves. The speed of applications are also limited to the availability of spray rigs and how fast they can move through each block. With all of these factors we have to predict when the orchard will be dry enough for tractors and when we can get back to apply the water.
In the above example, this orchard was set up at the beginning of May to regain moisture back to the deeper profile. From previous irrigation at the end of April we can see that it takes five days to move from field capacity to our upper tension threshold. Knowing that the orchard would need water within five days there was a conscious decision to spray the field three days after the previous irrigation. After three days, the soil on the surface floor was dry for equipment and the soil tension remained within the tree’s root zone — moving to the middle of the crop comfort zone. These conditions were optimal for both the orchard and the equipment because we prevented ruts and maintained nutritional flow to the canopy of the trees. Conditions that would have raised concerns for the orchard would have come from spraying just a day after irrigating, or waiting for the tree to run out of available water before spraying and then irrigating.
Blocks that have maintained proper soil tension levels while mowing and spraying have kept more nuts on the trees and maintained size. Extended periods of stress in other orchards have displayed shrivel and even nut drop. I’ve also noticed a direct correlation with good infiltrations of water in blocks that have had good irrigation timing. These blocks have shown far less pooling issues than blocks that have suffered from high tension and less frequent irrigations.
Blocks that have also had infiltration issues have been more difficult to schedule sprays because of wet spots left within the orchard. From previous years, this is the time where well managed orchards stay in the grove and other orchards become a management headache.
By staying on top of our irrigations in almonds, we can greatly reduce other issues within the orchard and the crop for this season and for seasons to come.
For any questions on scheduling please contact your local Hortau Irrigation Management Advisor.
About the Author
Irrigation Management Advisor Travis Goldman was born and raised in Watsonville and currently provides irrigation scheduling services to growers in California’s Central Valley. He graduated from UC Davis and has worked throughout California as a service technician, grower support specialist and irrigation management advisor to learn and understand every aspect of Hortau’s irrigation management platform.