California Almonds: Growers Move Into Hull Split Spraying With Plenty Of Approaches – AgFax

    Almonds at hull split. ©Sara Savary, AgFax Media

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    Owen Taylor, Editor
    Jenny Holtermann, Contributing Editor


    Almond hull split spraying will gain momentum as we head into the first full week of July.

    The number of sprays can vary every year on a given ranch, depending on an orchard’s sanitation results, trap counts and last year’s reject percentages. Lower almond prices also are being factored into some decisions this year.

    Pistachios are approaching nut fill. Fertilizer and irrigation management remain critical.

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    John Moore, PCA, Growers Crop Consulting, Bakersfield

    “The majority of my growers have been making their first hull split sprays this week. Those with high reject counts last year will make a total of three sprays. The first of those started on June 20. These tend to be in older orchards with less effective sanitation methods. Most younger orchards will receive one or two applications.

    “Our hull split sprays are targeting peach twig borer as well as navel orangeworm. PTB flights tend to be a week ahead of NOW flights, so they require earlier sprays. Each spray is generally two weeks apart, with the final hull split spray going out two weeks before harvest.

    “We included a miticide in some of the first hull split sprays. Mite issues tend to be very sporadic this year, and a handful of growers already have had to spray four times. By contrast, others haven’t had to apply a miticide at all. An orchard’s soil type is a factor, and hot spots tend to show more on high-salt soils.

    “Where hull rot has been an issue in the past, growers are applying fungicides. Growers who made an April, May and June alternaria spray tend to have less hull rot problems. We’re seeing small areas with stinging or gumming due to leaffooted plant bugs.

    “NOW traps in pistachios are peaking at 10 in the highest areas. We applied the 1700-hour NOW spray in June, and we’ll make the 2200 spray toward the end of July. Black lesions continue to develop in pistachios. True bugs remain a problem. In traps, we’ve found eggs but no adults.

    “We are finding more NOW adults in walnut orchards in traps up high, while counts in the lower traps remain minimal. Husk fly and San Jose scale pressure is low, as well, especially compared to what we dealt with last year. Traces of sunburn are evident, and we’ll apply a sun protectant as temperatures rise and more signs of burn show.

    “Walnut growers with younger orchards are battling weed pressure in areas where more sunlight reaches the orchard floor. Growers are switching back and forth between herbicides to maintain control.

    “Lygus pressure has been running low in cotton this year. Squares continue to develop, and this should be a nice crop.”


    Phoebe Gordon, Orchard Farm Advisor Madera and Merced Counties

    “I’ve seen some blanks beginning to split in the Madera area, and I anticipate that splitting will start soon in the rest of the crop. Blanks tend to split one to two weeks before the main crop. Check fruit as it begins to split to make sure your NOW spray protects the crop and not the blanks.

    “Mites haven’t developed much, although people are finding them.

    “Crews are preparing almond orchards for harvest. Ideally, use pressure chambers to manage irrigation as you pull back on volume during hull split.

    “Monitor for early splits in pistachios. NOW can feed on these nuts, and that can lead to aflatoxin issues.

    “July is an optimal time to pull leaf samples ahead of planning next year’s nutrient program.”


    Chris Morgner, PCA, Agri-Valley Consulting, Merced

    “We are starting to see blanks splitting near the end trees. A few growers in the Los Banos area began spraying yesterday (7/1), and that will likely begin on a wider scale in our area from July 4 to July 7. Depending on a number of factors, a few growers won’t make a hull split spray in Nonpareils. They’ll wait to treat when the pollinators split towards the end of July.

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    “We are encouraging growers to quit spraying by 10 a.m. when the temperatures are higher than 80 and humidity drops below 40%. In those conditions, spray deposits tend to evaporate before they reach the tree.

    “We’re finding an uptick of moths in our NOW traps, and we are seeing a few eggs on early hull splits. Mating disruption puffers are in 15% to 20% of our almond orchards, and the puffers help control NOW populations and minimize the urgency to spray.

    “The next round of NOW flights will occur in 3 to 4 weeks, and that’s when we plan to apply the second hull split spray. Sprays will be contingent on monitoring, historical reject counts and sanitation methods. The second hull split spray is the most critical because NOW damage tends to be more significant in the pollinators.

    “Rust hasn’t gone away all season, and most growers will include a fungicide where rust is prevalent. We applied a fungicide on a few fields in late May, which should give us coverage through hull split.

    “Ant bait continues to go out in almond orchards. Younger blocks with significant ant populations will need a second application closer to harvest. Harvest looks to be 5 to 6 weeks away at this point.

    “Eight organic almond orchards have heavy mite pressure. In two of the eight fields, trees already are losing leaves due to damage. Minimal mite populations have developed in conventional orchards, and we only have had to spray a half a dozen of those fields.

    “Predators have mostly been controlling mites where they did build. Growers who choose to include a miticide in their hull split spray will do so in their second application – towards the end of July.

    “Many growers are practicing deficit irrigation in almonds to control hull rot. They are reducing irrigation to 90% of ETC for Nonpareils. One ranch is cutting back to 80% for next week. Closer to the middle of July, when hull split is more evident in Nonpareils, growers will cut back to 50% ETC for two weeks and keep pollinators at 90%. Then, the Nonpareils will go back to 90% after the deficit irrigation cycle.

    “Deficit irrigation also will help control the increasing weed growth. Growers will terminate the center growth and apply a herbicide broadly to manage weed progress.

    “In walnuts in our area, codling moth pressure is running on the low side. A preventative miticide is going out in places, although most growers are not spraying. At least right now, fertilizer and irrigation are the main activities in walnuts.

    “Pistachios are transitioning into nut fill, and growers are boosting irrigation amounts by 15% to accommodate growth.

    “Tomatoes are faring well in the heat. Growers are applying foliar nutrients in select fields and are including an insecticide for armyworms. Some sulfur dust also is going out. Cotton is blooming and is at 14 to 15 nodes. We’re applying a miticide on early corn varieties. Corn has tasseled out. In alfalfa, we are treating for western striped armyworm.”


    Franz Niederholzer, UC Farm Advisor, Colusa, Sutter and Yuba Counties

    “We are right in the middle of hull split spraying in our area. Sound nuts are beginning to show splits. The crew at the Nichols Soil Lab sprayed edges last Saturday (6/27) and will start our first full round of hull split spraying tonight (7/2).

    “At least one larger grower in the area began spraying late last week. He has early orchard locations, plus a lot of ground to cover. More growers began spraying this week, and we definitely are into the second-generation NOW flight.

    “As of July 2, we are at 1321 degree days for NOW and 1571 DD for PTB, based on a March 12-13 biofix at Nickels. We will see if that biofix was correct, given this spring’s rollercoaster weather.

    ©Sara Savary, AgFax Media

    “July is a critical time for irrigation management. While nut length and kernel size and fill will occur by the end of May, kernel weight keeps increasing from June through the first week of August, roughly speaking. That weight increase depends on adequate irrigation management and isn’t related to nutrition.

    “Moderate water stress for a short period in early hull split is helpful. Pressure chamber readings for moderate stress range from minus 14 to minus 18 bars. This early hull split irrigation reduction – strategic deficit irrigation (SDI) – lasts for 2 to 3 weeks, depending on locations and the need to control hull rot as well as for managing harvest.

    “Once we reach about the middle of the second week of July, the SDI window should close and growers will again deliver full ET to trees until harvest. Extended periods of moderate to high water stress – more than minus 18 — will increase sticktight hulls.

    “Walnuts have a big crop ahead of them. The overall recommendation for walnut nitrogen management is to deliver a quarter of the total nitrogen budget each month from May through August. The July installment on the plan is coming due.

    “I’ve heard reports of very early husk fly catches, although we haven’t caught any at Nickels. Codling moth populations have been irregular across the region, with high pressure in places and light numbers in other locations.”


    Gary Gliddon, PCA, Treevine Consulting, Modesto

    “Hull split is barely starting in most orchards. Only a couple of growers have already begun spraying, but the majority will start on Monday (7/6). Independence seems to be splitting ahead of Nonpareil.

    “Many growers are considering a single hull split spray and will include a miticide for prevention. Growers with a history of high rejects will likely spray twice. Those making a second spray will hold off and include a miticide in that later application.

    “Navel orangeworm egg counts are increasing on traps. Pheromone traps are also up to 15 to 20 per week, and those counts will likely increase. Signs of rust are apparent in a few more orchards as we approach harvest.

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    “In walnuts, codling moth trap counts are increasing in the Chandlers. Last year’s numbers ran quite a bit lower. We have yet to see any husk fly this year.”


    Todd Fukuda, Weinberger and Associates, Hanford

    “Almond growers in the area started perimeter hull split sprays this week. In the middle to latter part of next week, growers will begin full-field sprays on a larger scale. That timing is pretty typical in our area.

    “Some growers will apply a second NOW spray for control in pollinator varieties. To determine whether to make that second spray, we’ll regularly monitor crack outs. These two sprays are usually two weeks apart.

    “We will add a miticide where populations have started building. As growers start into deficit irrigation before harvest, mite populations may increase.

    “Over the last two weeks, two growers started seeing mites flare up, and we have been applying a miticide in those orchards. Overall, though, mite pressure has been relatively low this year.

    “Pistachio growers are gearing up for another fungicide spray in 10 to 12 days for alternaria and botryosphaeria. What we find in early splits or pea splits will determine if a navel orangeworm material is necessary. If we see the shell and hull split to the point that the meat is exposed, we’ll apply a residual NOW material.

    “We have started detecting traces of citrus flat mite in some pistachio orchards. A sulfur blend will be added to the fungicide spray in areas with a history or current presence of flat mite. We had actually witnessed a decrease in populations over the last several years.

    “Pistachio growers continue to fertilize and irrigate regularly during this critical nut development stage.

    “We’re closely monitoring younger pistachio orchards for chinch bugs, but populations and the number of fields with chinch bugs have decreased. Young blocks with large growth developing may need a round of foliar nutrients

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