California Ag Network

Tag: NOW

  • American Pistachio Growers Awarded $1 Million for Regional Pest Management Collaboration

    American Pistachio Growers (APG), in collaboration with Washington State University, University of California – Riverside, UC Cooperative Extension, the USDA Agricultural Research Service and regional nut industry partners, has been awarded a $1 million grant through the California Department of Food and Agriculture’s Biologically Integrated Farming Systems (BIFS) Program to develop a Regional Integrated Pest Management (IPM) network for Navel Orangeworm (NOW) — the most damaging pest in California’s tree nut industry.

    The project, led by Dr. Houston Wilson (UC Riverside), Dr. David Crowder (WSU), Dr. Jhalendra Rijal (UC IPM), and Dr. Charles Burks (USDA ARS) will pilot a groundbreaking Decision Aid System (DAS) that integrates real-time trap data, weather models, and crop phenology into a single communication platform. The goal is to improve the timing and precision of pest control decisions while fostering regional cooperation among almond, pistachio, and walnut growers.

    “This project moves us beyond the farm gate,” said Joe Coelho, APG’s Director of Sustainability and Member Outreach, who serves as Technical Agronomist and PCA on the project. “For the first time, growers across commodities will have access to shared regional data and communication tools that allow them to anticipate pest pressure before it hits their fields and ultimately make precise, timely treatment decisions. The outcome is fewer sprays, lower costs, and higher quality nuts.”

    Through field-level data acquisition, the system’s meta-analytics will identify regional flight trends coupled with crop-specific phenological development and enhance forecasting of NOW flights — critical steps in breaking the pest’s lifecycle across neighboring farms. Ultimately, the program is expected to help reduce pesticide use, improve nut quality, and lower aflatoxin risk associated with pest damage.

    APG will serve as the grower administration partner, coordinating grower participation and outreach. Carlee Branco, APG Grant Programs Administrator, will conduct on-farm grower coordination, engagement and data collection. “This is a major milestone for sustainable pest management,” said Coelho, “and it demonstrates APG’s leadership in advancing research that directly benefits growers.”

    The Regional IPM for Navel Orangeworm Project represents a pivotal step toward the state’s Sustainable Pest Management (SPM) Roadmap by providing a scalable, data-driven framework that can be expanded statewide.

    “This is exactly the kind of innovation California agriculture needs,” said Dr. Wilson. “Regional coordination is essential to long-term pest reduction, especially for highly mobile insects like the navel orangeworm, and this project will now put those ideas into practice at scale.”

    The program launches in early 2026, with pilot regions in West Fresno County and Modesto, serving as the foundation for a future statewide expansion. Growers within these territories who are interested should contact Carlee Branco for more information at cbranco@americanpistachios.org.

    American Pistachio Growers (APG) is a non-profit trade association representing more than 800 growers and processors across California, Arizona, and New Mexico. APG’s mission is to enhance grower profitability through global marketing, industry research, and sustainability initiatives that promote economically viable and environmentally responsible pistachio production.

  • How Late is Too Late for Winter NOW Orchard Sanitation?

    The removal of nuts remaining on almond trees from the prior year’s crop is an important winter sanitation practice for the management of navel orangeworm (NOW), Amyelois transitella. Residual nuts are called ‘mummies’ and the process of removing the mummies is referred to as a ‘mummy shake’ because they are mechanically shaken from trees. This practice is conducted during the dormant and delayed dormant season, a time when orchard access may be thwarted by the winter rains.

    Most growers strive to have the mummy shake complete by mid-January when buds are dormant and less likely to abscise from the vibration caused by a mechanical shaker. As the flower buds progress toward bloom, they become more sensitive to the shaker vibration and more likely to abscise. Studies conducted in the 1980s (Sibbett et al.) established that the shaking of mummies by January 31 (approximately 8 days prior to bloom) at a Kern County site did not adversely affect yield; however, the authors cautioned growers of the risk of delaying mummy shakes further, particularly on early blooming varieties and in locations in the southern San Joaquin Valley. Because bud development and bloom date advance with increasing latitude, the potential risk of early and mid-February mummy shakes was investigated by W. Asai (Pomology Consulting, Turlock, CA) in the northern San Joaquin Valley. This work, conducted at a more northern latitude, suggested shakes conducted in early February may not compromise yield.

    The lack of yield detriment attributed to a mummy shake-mediated bud loss may seem counterintuitive; however, simple concepts of tree physiology may help explain this phenomenon. Consider that only approximately 30% of the flowers on a tree set a crop. A given tree does not have the carbohydrate stores needed to set every flower. As a result, the loss of a subset of flower buds may have little effect on overall yield. Naturally, the risk of crop loss increases the closer the shake approaches bloom, and both research groups suggested that mummy shakes be complete prior to the pink bud stage of development.

    Although rainy years make it difficult for growers to access orchards and complete orchard sanitation tasks, the heightened soil moisture adversely affects NOW survival in comparison to dry winters. Mummy nuts on the ground support enhanced NOW survival on a dry orchard floor than on moist soil with winter vegetation in the row middles. The next step in managing overwintering populations of NOW is destruction of mummies by flailing or mowing. Flailing and mowing should be completed by March 1, prior to the emergence of NOW. The emergence profile of NOW varies by location, but the first flight generally starts in late March.

    Growers who have not completed their winter sanitation practices by the end of January should walk their orchards to assess bud development in consideration of a delayed mummy shake. Winter sanitation can reduce now damage by up to 80%, so an early February shake may be worth the effort if orchard access is possible and bud development has not advanced into pink tip. For more information on NOW management, visit www.ipm.ucdavis.edu. — By Cameron Zuber & Elizabeth Fichtner, UCANR

  • Preparing for Almond Hull Split

    Almond experts say there is only one proven way to know when hull split begins: inspect your trees from the top down, starting in the southwest corner of the canopy.

    The importance of knowing precisely when hull split occurs is critical because it signals the proper timing for treatments to control navel orangeworm (NOW) and, as appropriate, hull rot. Whether growers use a ladder, climb atop a pruning tower or lop off a few high branches with extension pruners, the goal is to understand what’s happening in the top of the tree, where nuts mature at a faster rate.

    Simply looking up into a tree’s canopy from the orchard floor is a sure fire way to miss the advent of hull split. When hulls split, a scent is released into the air, attracting female NOW moths to lay their eggs on the suture of the splitting hull. As the hull splits, fungal spores also can enter and spawn hull rot infections.

    Missing the beginning of hull split and allowing NOW or pathogens to gain a toehold in an orchard can wreck a grower’s entire season and reduce the value of the crop, costing growers in returns if nuts are rejected after harvest.

    Summer split invites unwanted guests

    Growers can determine if hull split has occurred – and if it’s time to spray – if, when they squeeze the end of the hull, the entire suture opens up, exposing the shell within.  Almond hulls split as the fruit ripens, and timing varies based on weather conditions and variety. For instance, the variety Nonpareil typically splits in early- to- mid-July, earlier than some other varieties.

    However, it’s at the stage before this, when the hull is split in a deep “V,” that susceptibility to NOW and wound pathogens that cause hull rot (Rhizopus, Aspergillus, and Monilinia) increase, making it vitally important that growers actively monitor their trees.

    Vice President of Member Services for Blue Diamond Growers Mel Machado advises growers to look for blank nuts – those without a kernel inside – as those hulls are the first to split, several days ahead of the “sound” nuts (those with a full kernel).

    Mel Machado, Blue Diamond Growers

    “The blanks are like the warning shot, signaling the start of hull split,” he said. “When full hull split does occur, the nuts at the top of the canopy will open up first.”

    Experts say growers should pay attention to trees on the edge of their orchards as they often ripen more quickly. Growers should also closely monitor the upper and outer portions of the canopy, particularly the southwest quadrant of the orchard block where the hot afternoon sun aids in the splitting and drying process.

    “Better to be too early than too late”

    Hull split applications should be made no later than at 1% hull split. This is the most effective time to spray for NOW as it often coincides with initiation of the second NOW flight.1

    Once growers identify hull split in their orchard, their next step should be to initiate timely treatment. Experts warn that waiting too long to begin spraying will cost growers, as will performing a poor spray job.

    Machado advised, “It’s better to be a bit on the early side than late” when spraying. Once hull split begins, he recommended the entire orchard be sprayed in five days or less. “If it takes 10 or 15 days, that’s too long,” he said.

    Planning ahead – especially for smaller growers who rely on custom applicators – is essential.

    “Watch your fields closely and be in contact with your operator early on,” Machado advised.

    In larger orchards, Machado advises growers consider starting with aerial sprays, recognizing that ground-based sprays don’t always provide complete coverage at the tops of the trees.

    “We’re seeing growers effectively incorporate aerial applications into their treatment programs for the first application in order to cover the acreage in a timely manner,” Machado said.

    The best time to spray is early in the morning or at dusk.

    “Do not spray in the heat of the day – your application will evaporate into thin air and you won’t get the material where it needs to go. That’s a waste of time and money, as you’re not only wasting spray material but you also won’t achieve the coverage necessary to combat crop damage,” Machado said.

    Finally, growers should ensure their ground-based sprayers are properly calibrated, the nozzles are unplugged and that air flow isn’t restricted. Once it’s time to spray, growers should remind applicators to drive no more than two mph through orchards to ensure optimum coverage and to drive down each row to ensure the trees are equally covered.

    “There are some guys who spray every other row, and that’s not a good idea,” Machado said. “There are two sides to the tree; you need to spray both of them.”

    Machado reinforced that hullsplit sprays offer the final chance to manage NOW populations before harvest. Still, these applications are only part of a coordinated, year-round, integrated pest management plan to combat NOW that also must include winter sanitation and mating disruption, both of which are performed earlier in the crop year. — By the Almond Board of California

  • Almond Board Mummy Shake Video Contest

    Halloween will come and go, but mummy nuts are here to stay… unless you shake them away!

    To help remind growers to break the link between mummy nuts and overwintering navel orangeworm (NOW), the Almond Board of California (ABC) created a parody song that’s sure to be an “orchard smash,” just in time for the most spooky holiday of the year. It’s The Mummy Shake — listen now (lyrics here) and submit a video of your family dancing along to this “orchard smash” for a chance to win a $500 Amazon gift card!

    How to Enter: Video Specifications  

    • Create a video with family dancing – and, if desired, singing – to The Mummy Shake. You can film this video anywhere, though an orchard backdrop is encouraged.
      • Entry videos must be at least 30 seconds in length (approximately a verse and a chorus) and up to the duration of the full song.
      • Entries will be judged based on enthusiasm, creativity and composition.


    How to Upload Your Video

    • You have TWO OPTIONS when submitting your video:
      • Get Up and Dance: Don’t worry about singing; just get out in the orchard and show us your moves and/or lip-sync the lyrics. We’ll add the audio to your video!
      • Sing-Along Style: Get out in the orchard, play the Mummy Shake video and sing along with the lyrics!
    • Submit your entry in one of two ways:
      • Upload the video in .MP4 or .MOV format to this ABC webform.
        • MAKE SURE TO INCLUDE THE CONTESTANT’S NAME AND EMAIL ADDRESS IN THE FILE NAME
      • Post the video on the Almond Board of California Facebook page 
        • DON’T FORGET to include the hashtag #MummyShake in your post to ensure your video is considered for the $500 Amazon gift card!

    Read on below for complete contest eligibility guidelines.

    Mummy Shake Video Contest – OFFICIAL RULES

    NO PURCHASE NECESSARY TO ENTER OR WIN. MAKING A PURCHASE OR CONTRIBUTION WILL NOT IMPROVE CHANCE OF WINNING. VOID WHERE PROHIBITED.

    1. Preliminary Information and Contest Period: The Mummy Shake Video Contest (Campaign) is open for entries starting October 26, 2020 at 12:01AM Daylight Pacific Time (PT). All entries must be submitted by the contest deadline: 11:59PM PT on November 20, 2020 (Contest deadline). Campaign is subject to all applicable federal, state and local laws. This Campaign is sponsored by the Almond Board of California (Sponsor), 1150 9th St. #1500, Modesto, CA 95354.

    2. Agreement to Rules: By participating, the Contestant agrees to be fully and unconditionally bound by these Rules and decision of Sponsor, which shall be final and binding. Contestant represents and warrants that they meet the eligibility requirements. In addition, Contestant agrees to accept the decisions of Sponsor as final and binding as it relates to the content of this Campaign.

    3. Eligibility: Contestant may enter to win if he or she is a legal resident of the state of California, age 18 or older at the time of entry, and is a member of the California almond industry, which includes growers, handlers, hullers/shellers and allied industry members. Contestant’s submission may include family member and/or friend of a Contestant provided that such family member or friend consents to being featured in the submission. If Contestant chooses to feature his or her children under the age of 18 in his/her submission, Contestant grants Sponsor permission to display, broadcast and/or share video for promotional purposes of this Campaign or future Campaigns. Employees, officers, directors, agents, representatives and their immediate families (parents, children, siblings, spouse and each of their respective spouses, regardless of where they live) or members of the households of the Almond Board of California/Sponsor, their parent companies, subsidiaries, agencies and anyone connected with the production and distribution of this Campaign may submit an entry for use by Sponsor solely to promote the Campaign, but are not eligible to win or be awarded a prize.

    4. How to Enter: To enter, Contestants must create a video featuring themselves and/or family or friends dancing to the Almond Board of California’s “Mummy Shake” song, in an almond orchard or another setting of their choosing. Entry videos must be at least 30 seconds in length (approximately one verse and one chorus) and up to the duration of the full song. Entries will be judged based on enthusiasm, creativity, and composition. Judges will be comprised of employees of the Almond Board of California. Submit your video entry in one of two ways:

    • Upload the video in .MP4 or .MOV format to this ABC webform. 
      • MAKE SURE TO INCLUDE THE CONTESTANT’S NAME AND EMAIL ADDRESS IN THE FILE NAME.
    • Post video on Sponsor’s Almond Board of California Facebook page: http://facebook.com/AlmondBoardofCalifornia/
      • DON’T FORGET to include the hashtag #MummyShake in your post to ensure your video is considered for the $500 Amazon gift card!
    • Email industry@almondboard.com with questions

    Multiple entries per person or household will be accepted and judged, but only one (1) prize will be awarded per person or household. Entries that are incomplete or that contain errors, copyrighted images or inappropriate/derogatory/defamatory images or language, dogs in the orchard, guns/firearms, nudity, violence or profanity will be automatically disqualified in Sponsor’s sole discretion. Sponsor is not responsible for lost, late, misdirected, altered or destroyed entries. The odds of winning depend on the number of eligible entries received and/or the number of contestants participating in the contest. If Contestant uses fraudulent methods or otherwise attempts to circumvent the rules, the submission may be removed from eligibility at the sole discretion of Sponsor. The Contestant may be asked to provide all appropriate clearances, permissions and releases for the submission.

    All entries become the property of Sponsor and will not be returned. Proof of sending will not be deemed proof of receipt by Sponsor. Sponsor reserves the right to edit or summarize the submission or any written description or picture prior to posting to Sponsor’s website and/or social media channels.

    5. Prize: The Winner of the Campaign (“Winner”) will receive a Grand Prize consisting of a $500 Amazon gift card.

    The prize will be sent to Winner’s provided email address within two (2) weeks of notification. Any applicable Federal, State or Local taxes are solely the responsibility of the winner and paying any expenses associated with any prize which are not expressly included as part of the prize. Prizes are not transferable. Sponsor reserves the right to substitute a prize package with another prize of equal or greater value if advertised prize or any component thereof is not available.

    6. Winner Selection and Notification: Winner will be selected under the supervision of the Sponsor. Winner will be notified by email or by direct message on Facebook within five Sponsor business (5) days following selection of Winner. Sponsor shall have no liability for Winner’s failure to receive notices due to spam, junk email, or other security settings or for Winner’s provision of incorrect or otherwise non-functioning contact information. If Winner cannot be contacted, is ineligible, fails to claim the prize within seven (7) Sponsor business days from the time award notification was sent, or fails to timely return a completed and executed declaration and release as required, the prize may be forfeited, and an alternate Winner selected. Receipt by Winner of the prize offered in this Campaign is conditioned upon compliance with any and all federal, state, and local laws and regulations. Any violation of these official rules by winner (at Sponsor’s sole discretion) will result in Winner’s disqualification as Winner of the Campaign, and all privileges as Winner will be immediately terminated.

    7. Rights Granted by Contestant: By entering this Campaign, Contestant understands and agrees that Sponsor, anyone acting on behalf of Sponsor, and Sponsor’s licensees, successors, and assigns, shall have the right, where permitted by law, to print, publish, broadcast, distribute, and use in any media now known or hereafter developed, in perpetuity and throughout the World, without limitation, Contestant’s entry, name, portrait, picture, voice, likeness, image, statements about the Campaign, and biographical information for news, publicity, information, trade, advertising, public relations, and promotional purposes, without any further compensation, notice, review, or consent. By entering this Campaign, Contestant represents and warrants that entry is an original work of authorship and does not violate any third party’s proprietary or intellectual property rights or right of publicity. If entry infringes upon the right of any third party including, without limitation, any intellectual property right or right of publicity, Contestant will be disqualified at the sole discretion of Sponsor. If the content of the entry is claimed to constitute infringement of any proprietary or intellectual proprietary rights or right of publicity of any third party, Contestant shall, at his or her sole expense, defend or settle against such claims. Contestant shall indemnify, defend, and hold harmless Sponsor from and against any suit, proceeding, claims, liability, loss, damage, costs or expense (including attorneys’ fees), which Sponsor may incur, suffer, or be required to pay arising out of such infringement or suspected infringement of any third party’s right.

    8. Terms & Conditions: Sponsor reserves the right, in its sole discretion, to cancel, terminate, modify or suspend the Campaign should virus, bug, non-authorized human intervention, fraud, or other cause beyond Sponsor’s control corrupt or affect the administration, security, fairness, or proper conduct of the Campaign. In such case, Sponsor may select the Winner from all eligible entries received prior to and/or after (if appropriate) the action taken by Sponsor. Sponsor reserves the right, in its sole discretion, to disqualify any individual who tampers or attempts to tamper with the entry process or the operation of the Campaign or website or violates these Terms & Conditions. Sponsor has the right, in its sole discretion, to maintain the integrity of the Campaign, to void entries for any reason. Any attempt by a Contestant to deliberately damage any website or undermine the legitimate operation of the Campaign may be a violation of criminal and civil laws. Should such attempt be made, Sponsor reserves the right to seek damages to the fullest extent permitted by law.

    9. Limitation of Liability: By entering, Contestant agrees to release and hold harmless Sponsor and its subsidiaries, affiliates, advertising and promotion agencies, partners, representatives, agents, successors, assigns, employees, officers, and directors from any liability, illness, injury, death, loss, litigation, claim, or damage that may occur, directly or indirectly, whether caused by negligence or not, from: (i) such Contestant’s participation in the Campaign and/or his/her acceptance, possession, use, or misuse of any prize or any portion thereof; (ii) technical failures of any kind, including but not limited to the malfunction of any computer, cable, network, hardware, or software, or other mechanical equipment; (iii) the unavailability or inaccessibility of any transmissions, telephone, or Internet service; (iv) unauthorized human intervention in any part of the entry process or the Promotion; (v) electronic or human error in the administration of the Promotion or the processing of entries.

    10. Disputes: This Campaign is governed by the laws of the United States of America and California, without respect to conflict of law doctrines. As a condition of participating in this Campaign, participant agrees that any and all disputes that cannot be resolved between the parties and causes of action arising out of or connected with this Campaign, shall be resolved individually, without resort to any form of class action, exclusively before a court located in California having jurisdiction. Further, in any such dispute, under no circumstances shall participant be permitted to obtain awards for, and hereby waives all rights to, punitive, incidental, or consequential damages, including reasonable attorney’s fees, other than participant’s actual out-of-pocket expenses (i.e. costs associated with entering this Campaign). Participant further waives all rights to have damages multiplied or increased.

    11. Privacy Policy: Information submitted with an entry is subject to the Privacy Policy stated on the Sponsor’s website. To read the Privacy Policy, click here.

  • Orchard Sanitation is key to a Quality Almond Crop

    Navel orangeworm (NOW) is the key pest of almonds, causing more income loss due to reject nuts than any other pest. Pesticide sprays, alone, cannot control this pest. A combination of several specific practices has been proven to reduce NOW damage and limit loss of grower income. These practices are winter sanitation, timely harvest and pesticide sprays (where needed). Mating disruption is an additional option that is seeing increasing adoption. The first of these practices on the orchard calendar is sanitation.

    Navel orangeworm find food and shelter in unharvested (“mummy”) nuts through the winter and spring, making those mummies a bridge of trouble from one year to the next in your orchard. Multiple research studies show that NOW damage increases with increasing mummy counts the previous winter. Destroying mummy nuts is the first step towards a cleaner crop and improved grower returns through quality incentives from processors. The goal of orchard sanitation is to turn that “NOW bridge” from a four-lane highway (no sanitation at all) into a narrow footbridge.

    Orchard sanitation is practiced by removing mummy nuts from the trees by February 1 and destroying (flail mow or disc) all nuts on the orchard floor no later than March 1st. In light of the expected reduced nut price for the 2020 crop, some growers may consider eliminating this key step in NOW management to “save money”. This is a risky move. The Sacramento Valley 2021 crop has a good chance to be lighter than the record 2020 crop resulting in 1) fewer nuts/tree and so higher % damage even if NOW populations stay the same and 2) larger nuts, on average, with the potential for poor shell seal and greater risk of NOW damage. Don’t play Navel Orangeworm Russian Roulette with your next crop. Sanitize.

    The following steps are needed for effective orchard sanitation:

      Before January 15, scout an orchard and count mummy nuts in 20 trees per acre. Include all varieties in this count.

      If average number of mummy nuts/tree exceeds 2, sanitation is recommended. The <2 mummies per tree target was developed in the early 1980’s, when industry average NOW damage was around 3.5%, much higher than today’s range of 1.3%. In the high pressure area of the southern San Joaquin Valley, the recommendation is to limit mummies to 1 per 5 trees (0.2 nuts/tree) and 8 or fewer mummies on the ground per Nonpareil tree, based on research from in 2003-2006 in Kern County. However, in 2019, northern California had higher % rejects level than the “high pressure” south San Joaquin Valley. Simply put, the fewer mummy nuts in an orchard, the lower NOW pressure at the start of the season.

      To sanitize, shake trees to remove nuts by January 31. Shaking can remove flower buds as they begin to swell and gain weight in late January/early February. Unless it is an early bloom season and buds begin to swell ahead of normal timing, shaking can be done into early February without reducing yield. Some buds are removed by shaking in early February, but since only 25% flower set = good commercial crop, some bud loss does not mean less crop at harvest. Some growers hand poll after shaking if too many nuts remain.

      Sweep downed nuts into windrows and mow or disc by March 1. Mow slowly (2 MPH) and check for intact nuts after mowing. If some nuts remain intact, mow again. NOW can survive if the nut is intact.

    Final thought. NOW overwinter in almond, walnut and pistachio mummies. NOW are also strong flyers, traveling at least a quarter of a mile to lay eggs. If you sanitize, but your neighbor(s) don’t, your orchard is at risk from NOW damage due to mated female moths, ready to lay eggs, flying over from the neighbors. Talk with your neighbors about sanitizing all orchards in the area and removing seedling “wild” almonds along fence lines as these can harbor NOW, too. — By Franz Niederholzer, UCCE Farm Advisor, Colusa & Sutter/Yuba Counties

  • Navel Orange Worm Update

    Sacramento, Calif., (June 19, 2017) – Navel orange worm is the key pest in almond. Nut feeding by this pest directly reduces yield and grower income. For example, 1% damage* in a 2500 kernel lb/acre crop = 25 kernel lb/acre loss (and $62.5/acre at a price of $2.50/lb). Also, NOW damage is frequently contaminated with highly toxic fungus aflatoxin, which is carried by the pest. Certain major almond markets have an extremely low tolerance for aflatoxin.

    What should growers think about when planning for NOW management at hull split and harvest, particularly when egg and/or pheromone traps are largely empty in the spring?

    • NOW adults can fly a quarter of a mile. When hull splits starts in your orchard, your nuts can become vulnerable to moths from your neighbor’s orchard, if they are a quarter of a mile away, or less.
    • Time your hull split spray(s) based on crop sensitivity (hull split), not trap counts – especially in low pressure years. When NOW pressures are low, egg traps don’t always attract females for egg laying when flights begin – especially when there are thousands of splitting real nuts as competition.

    Here are some general reminders for NOW control as harvest approaches:

    • Harvest at 100% hull split. Shake your trees once the nuts have reached 100% hull split. NOW populations build with every generation (see graph below) and NOW females lay fewer eggs on harvested nuts than those nuts still in the trees. So get the nuts on the ground as soon as they are ready. For pictures and description of 100% hull split, see: http://ipm.ucanr.edu/PMG/C003/m003fchullsplit.html.
    • If you spray, spray early. Newer, soft pesticides used for NOW control last a long time and work well on eggs and small worms. Research by Dr. Frank Zalom, UC Davis Entomology Department, suggests that effective pesticide residual is in this order (roughly): Intrepid® 4 weeks > Altacor® 3 weeks > pyrethroids (Brigade®, etc.) 2 weeks. Consult with your PCA and consider spraying early, so eggs are laid on treated surfaces. This may mean starting to spray as blanks are beginning to split – depending on how long it takes you to get across the orchard. Why spray early when pressure is low? The longer you can keep the NOW population low, the lower the pressure will be later in the season when pollinators (Monterey, etc.) are splitting.
      Spray carefully. Field research results from Dr. Joel Siegel (USDA) and Ken Giles (UC Davis) have repeatedly shown that slower sprayer ground speed (2 MPH) and higher spray volume (150-200 gpa vs 100 gpa) delivers the best possible NOW control. Also, spraying when the humidity is higher (roughly 10 PM to 10 AM) means less spray evaporation and better coverage. Need to move faster? Consider using an additional sprayer instead of driving too fast and getting less control (lease/borrow?). If better spray timing could reduce damage by 0.5% (0.25% on your grade sheets*) in a 2500 kernel lb/acre orchard, that’s $31.25/acre/year back in your pocket before any quality incentives.