Postharvest nutrition: Use information from your leaf and hull tissue analyses along with 2023 yield and anticipated 2024 yields to plan your fall Boron, Potassium and Zinc applications. 1,000 lbs of almond kernels harvested removes 80 lbs of potassium from the field, so it’s important to wait until after harvest to develop your fall nutrition plan. These fall applications have an outsized impact on the following year’s yield. Nitrogen applied in the fall, however, does not benefit yield if an orchard is otherwise healthy. Read the Postharvest Nutrition Review for details on fall fertilizer applications.
Cover crops: Cover crops or resident vegetation have numerous benefits including improving water infiltration and holding capacity, providing additional forage for bees in the spring, and providing easier access to the field when the soil is wet. It’s important to monitor soil moisture and irrigate after planting a cover crop if we have a dry fall. This ensures good germination of your cover crop. Check out the
UC-Almond Board Cover Crop Best Management Practices Guide for information on timing, cover crop species selection, equipment and more.
Weed survey: After the first rain, scout for weeds and develop your weed management strategy for the next year. Correct weed identification is critical for effective management plans, so utilize the Weed Research and Information Center Weed ID Tool if necessary.
Winter sanitation: With reports of higher-than-average navel orangeworm damage in the 2023 harvest, winter sanitation will be necessary in most orchards. Count the mummies in 20 trees throughout each orchard. If more than 1 mummy nut per 5 trees is found, sanitize by shaking or poling nuts to the ground by Feb. 1 to reduce navel orangeworm pressure next year. Also note if mummy nuts are caused by hull rot, which may indicate a need to reevaluate your irrigation and nitrogen management practices next season. See the article on sanitation standards in this newsletter.
Pruning: Prune out dead or damaged branches, taking care to avoid pruning if rain is in the forecast within 14 days to minimize the risk of infection of fresh cuts by rain-spread pathogens. Applying Topsin-M after pruning also provides protection against canker pathogens like Cytospora and Botryosphaeriaceae.
Apply foliar zinc if deficient: Recent research in stone fruit showed that lower rates of zinc sulfate (5 lbs./acre) applied earlier in October were as effective in getting Zn into the trees as later sprays at higher rates without damaging leaves. Zn applied at a high rate (for example, 20+ lbs. zinc sulfate/acre) has the added benefit of defoliating trees, which may provide the advantage of reducing inoculum for the 2024 season in orchards where shot hole or rust were a problem. However, in a dry fall, heavy Zn applications will not defoliate trees.
Dormant spur sampling: Sample dormant spurs for scale and mite eggs and examine green shoots for scab lesions. Use this data to decide whether to apply a dormant spray to manage scale and mites and then watch for scab lesion sporulation in spring.
Honeybee planning: Get your order in for 2-3 honeybee hives per acre for self-sterile varieties for the spring pollination season. Self-fertile varieties should have 0.5-1 hive per acre. See our article on Honeybees, Colony Strength, and Beekeeper Challenges for best practices for using honeybees in the orchard.
Process harvest samples: November is a great time to pull those harvest samples out of the freezer and evaluate them to identify specific pest damage. — By Becky Wheeler-Dykes, Orchard Systems and Weed Ecology Farm Advisor, Glenn, Tehama, and Colusa Counties