Almond Orchard Management Considerations: February & March
Becky Wheeler-Dykes, UCCE Farm Advisor, Glenn, Tehama, and Colusa Counties
Luke Milliron, UCCE Farm Advisor, Butte, Glenn, and Tehama Counties

Weed management: Prepare your preemergent herbicide program with your PCA. Cost savings in mature orchards can be minimized by narrowing the weed-free strip and relying more heavily on mowing in the middles. Preemergent herbicide is much more effective when applied to bare ground than when soil is covered by dead leaves or weed cover, so clean strips as much as possible before application. Make sure young trees are adequately protected by cartons or sleeves. A table detailing currently registered herbicides is included in this newsletter.

NOW sanitation: Sanitation NOW (pun intended) is the #1 thing you can do to prevent another 2023 style infestation disaster. Reduce mummy nuts to no more than 2 mummies/tree on average by early February. Blow/sweep nuts into middles and flail mow or otherwise destroy the downed nuts by March 1. Sanitation is more effective with community management – encourage your neighbors to sanitize as well. Don’t overlook volunteer almonds along fence lines. Read more on the importance of sanitation in the “The case for orchard sanitation” found in this newsletter.

Irrigation maintenance: A thorough checkup of your well, pump, and irrigation system components is critical ahead of bloom to ensure the ability to mitigate frost damage. Growers in Tehama, Butte, Glenn and Shasta Counties can utilize free irrigation evaluations through the Tehama Resource Conservation District (RCD) Mobile Irrigation Lab. Growers in Yolo, Colusa, Sutter and Yuba Counties should contact the Yolo-/Sutter Mobile Irrigation Lab. Growers in Solano County can contact the Solano RCD.

Frost protection: The warmest orchard temperatures are when vegetation is maintained at 2 inches or shorter, the ground is firm (NOT cultivated), and moist. Be sure sprinkler irrigation systems are ready for deployment. Turn-on sprinklers when wet bulb temperature is above the critical temperature for the bloom stage in the orchard and turn off the sprinklers when the wet bulb temperature has recovered to above critical temperature. Frost increases the risk of bacterial blast damage.

Disease management: Check spray equipment and calibrate to prepare for bloom sprays. A single bloom spray (30-40% bloom) will protect the flowers if little to no rain occurred during bloom. The most recent fungicide efficacy and timing tables are included in this newsletter. Check with your PCA regarding blast control options if frost is in the weather forecast.

Bees: Talk with your beekeeper and use tools such as the BeeWhere system through CalAgPermits to check for beehive locations near your farm. Employ best practices to ensure honey bee safety.

Insect pests: Hang NOW traps in March to determine biofix. If using mating disruption, deploy dispensers by late March or early April. Although expensive upfront, UC research has shown that mating disruption can passively work in the background all season long, and yield a positive return on investment. Biofix dates for other pests should also be established by trapping. San Jose Scale and Oriental Fruit Moth traps should be hung by mid- to late-February. Peach Twig Borer traps should be placed by mid-March.

Nutrition: Nitrogen and potassium used by the crop should be replaced each year to maintain yields and long-term health of trees, even in lean price years. Approximately 68 pounds of nitrogen and 80 pounds of actual potassium is used for every 1,000 pounds of kernel yield removed from the field the previous year. Consult with your CCA as you consider the right time, place, material, and amount for all fertilizer applications.