DPG Foliar Sprays are expertly crafted to provide almond trees with essential nutrients during the critical hull split stage, a pivotal time for establishing robust bud development for the following season. These sprays deliver a precise blend of zinc, boron, and potassium, which work synergistically to enhance bud differentiation and strengthen tree vigor. The inclusion of carbon-based ingredients ensures superior nutrient absorption without the risk of tank precipitation, offering growers a sludge-free, highly efficient solution. By directly targeting the nutritional needs of almond trees, DPG Foliar Sprays maximize resource use, saving both time and money while promoting healthier trees and improved yield potential for the next season.
DPG Potassium Plus™, a patented potassium fertilizer containing 28.3% K₂O derived from potassium formate, is designed to meet the intense demands of almond trees during the challenging summer months. Its advanced formulation provides unmatched solubility, allowing for rapid potassium uptake by roots, which is crucial for maintaining water regulation and bolstering stress tolerance. This is particularly vital during extreme heatwaves, like those experienced in 2024, as it helps maintain turgor pressure and reduces wilting, ensuring trees remain resilient under high temperatures. By supporting carbohydrate reserve accumulation, DPG Potassium Plus™ enhances energy storage, further contributing to sustained tree health and productivity.
Beyond immediate nutritional benefits, DPG Foliar Sprays and Potassium Plus™ prioritize long-term soil health and sustainability. Their carbon-based, biodegradable formulations foster beneficial microbial activity in the soil without introducing harmful anions such as chloride or sulfate. This eco-conscious approach not only supports almond tree performance but also contributes to a healthier soil ecosystem, aligning with sustainable agricultural practices. For growers seeking reliable, efficient, and environmentally friendly solutions, DPG’s products deliver unmatched performance. Learn more at Deerpointgroup.com or contact The Deerpoint Group at 559-224-4000 for additional information on optimizing almond orchard nutrition.
Having trouble with filbertworm or brown marmorated stinkbug in your hazelnut orchard? The Yamhill Soil & Water Conservation District recently received IPM grant funding to provide free tools and resources to help hazelnut growers fight off these pests with a biological or mating disruption approach. Pacific Nut Producer Editor Matthew Malcolm met with Jordan Anderson and Brooke Karasch from the District to talk about the new funding and other services they provide to growers. Watch this brief interview to learn more and see what you may qualify for.
Leaffooted bug is a sporadic pest in almond, but damage can be significant in years when pest pressure is high. The pest may evade early detection by growers and PCAs because it overwinters as adults in vegetation outside of the orchard and tends to colonize the upper tree canopy, rendering it generally out of sight. As a result, pest pressure is often realized after damage has occurred. The damage may vary considerably between almond varieties, adding yet another challenge for diagnosis.
In Tulare County, heavy leaffooted bug damage was observed in May 2025 in almond orchards surrounded by citrus.Adult leaffooted bugs (Figure 1A) overwintered in the citrus and then entered the neighboring almond orchards in March and April. By early May, symptoms of infestation included extensive nut drop (Figure 2A) and gummosis on the nuts (Figure 2B). Although the adults were not observed in the orchard, the pest was identified based on the observation of the characteristic egg strands of leaffooted bug (Figure 1B). In orchards with Nonpariel and Aldrich, both varieties were affected; however, the nut drop was more extensive in Aldrich than Nonpareil (Figure 2A).
The full impact of the pest may not be realized until harvest because the quality of affected nuts remaining on the tree may also be compromised, thus reducing crop value. Nuts that are stung in late April to early July can be severely shriveled, have sunken lesions, or a brown spot depending on how developed the kernel was prior to feeding (Fig. 3, row 2-5).These nuts stay in the tree, are harvested, and can significantly increase the percentage of nuts classified as inedible during nut quality assessments.When examining a library sample of damaged kernels at harvest, nuts damaged by leaffooted bug fall into the same category as stink bug damage, as kernels damaged by these two pests are indistinguishable.
In 2007, UCCE Kern County Farm Advisors David Haviland and Mario Viveros had the opportunity to evaluate the relative susceptibility of 15 almond varieties to leaffooted bug damage. That year, leaffooted bug invaded a Kern County variety trial research block that included 15 varieties planted in replicated, randomized blocks. This unique situation allowed for unbiased evaluation of the performance of varieties under equivalent pest pressure. Results indicated that the average number of aborted nuts per tree ranged from 0 to 33% of the total crop. Additionally, at harvest, the estimated rejects from leaffooted bug damage ranged from 0 to 30% of the harvested yield. Researchers also noted that crop loss varied by variety, with Fritz exhibiting the highest crop loss at 63%, followed by Sonora, Aldrich, Livingston, Monterey and Carmel.The other varieties in the block had 3% or less total damage from the pest.
The underlying basis for the differential susceptibility of almond varieties to leaffooted bug is unknown. Damage does not appear to be related to harvest date or shell hardness at harvest. Other factors such as plant volatiles, hull thickness, or shell hardness in April and May when the bugs are present may play a role in varietal susceptibility. Haviland and Viveros also noted that varietal susceptibility is somewhat relative, explaining that Wood Colony exhibited low susceptibility to leaffooted bug in the research plot, but significant damage was reported on Wood Colony in commercial orchards when combined with less susceptible varieties (ie. Nonpariel and Carmel).These observations indicate that leaffooted bug prefers certain varieties, but in the absence of a preferred variety, the pest will remain in the orchard and feed on the most preferable variety of the less-preferred varieties present in the orchard.
The 2025 observations in Tulare County, taken in consideration with the 2007 data from the UCCE variety trial suggest that the best way to monitor leaffooted bug is to focus attention on the most susceptible variety in the field. Gummosis and nut drop in the most susceptible variety will serve as an indicator of pest pressure in a given orchard. Growers with Fritz, Sonora, Aldrich, and Livingston should be extra vigilant in monitoring pest pressure.Haviland and Viveros note that orchards composed of relatively unsusceptible varieties will have characteristically lower risk of leaffooted bug damage. Additionally, growers and PCAs should consider pest pressure from surrounding orchards and landscape plants that may serve as overwintering sites for the adults, thus contributing to the cryptic nature of the pest.
Management programs for leaffooted bug consist of monitoring for the pest and spraying primarily with pyrethroids, when needed. Pest management guidelines for leaffooted bug and other pests can be found at www.ipm.ucanr.edu and reports of Almond Board of California-sponsored research can be found at https://www.almonds.com/research-database. — By Elizabeth Fichtner, UCCE Farm Advisor, Tulare County, and David Haviland, UCCE Entomology Advisor, Kern County
Figure 2. Aborted nuts were prevalent on Aldrich, but the neighboring Nonpareil exhibited minimal damage (A). Gummosis and egg strands on aborted nuts indicated leaffooted bug damage (B).
Figure 3. Leaffooted bug predation affects the quality of nuts remaining on the tree. Unaffected nuts are represented in row 1; affected nuts of varying quality are represented in rows 2-5.
Figure 1. Leaffooted bug adults (A) are difficult to scout. Pest pressure is evident by the gummosis at feeding sites and the deposition of eggs in strands (B). Alternate hosts may harbor overwintering populations of leaffooted bug (C and D). Photos A, C, and D: W. Bentley.Figure 2. Aborted nuts were prevalent on Aldrich, but the neighboring Nonpareil exhibited minimal damage (A). Gummosis and egg strands on aborted nuts indicated leaffooted bug damage (B).Figure 3. Leaffooted bug predation affects the quality of nuts remaining on the tree. Unaffected nuts are represented in row 1; affected nuts of varying quality are represented in rows 2-5.
In California’s Central Valley, timing and precision are everything—especially during Hull Split, the most critical spray window of the season for nut growers. With the pressure on and no room for error, visibility into spray performance can make the difference between a successful season and significant crop losses.
A Fresno-based company with over a decade of experience serving nut growers, Fieldin has established itself as the gold standard in smart farm operations. With more than 300,000 acres of nut orchards under management, Fieldin’s platform helps growers streamline everything from spraying to mowing and harvesting, delivering actionable insights that improve efficiency and reduce costly mistakes.
Now, Fieldin is expanding its value with cutting-edge spray monitoring technology, just in time for Hull Split.
Introducing Remote Flow Monitoring
Through a new partnership with ARAG and PAS, Fieldin now offers real-time flow monitoring that gives growers precise, in-the-moment visibility into their spray operations. This technology eliminates the guesswork around what was applied and how much, allowing farm managers to make data-driven adjustments on the fly.
“The Hull Split spray is the most important of the season,” says Iftach Birger, Co-Founder and COO of Fieldin. “And when poor coverage means poor control, the risk of significant losses is real.”
Research shows that three factors drive Hull Split spray performance: spray speed, GPA (gallons per acre), and canopy size. With Fieldin’s Remote Flow Monitoring, growers gain live visibility into both spray speed and GPA—the two most critical metrics for Hull Split accuracy—without needing to replace existing equipment or disrupt current workflows.
Real-Time Visibility, Real-World Results
Many growers rely on maps or assumptions to confirm their sprays. But these can be deceiving. In one case, Fieldin’s coverage maps indicated a block was fully treated—but flow data revealed the spray rate dropped near the end, leaving key sections under-treated. In another case, a 20% drop in application rate went undetected until Fieldin’s flow monitoring flagged it in real time.
Without this technology, those issues would have gone unnoticed until it was too late, leading to reduced pest control, weakened nut quality, and potentially a second costly pass.
Fieldin’s solution changes that. With Remote Flow Monitoring, managers can:
Verify coverage and GPA targets in real time
Streamline the calibration process
Identify underperforming machines or crews (e.g., RPM issues or clogged nozzles)
Avoid missed applications and unnecessary re-sprays
Protect yield, quality, and long-term resistance management
Easy to Adopt, Built for the Field
Best of all, the system integrates seamlessly with most sprayers and is quick to install. No major equipment changes are required, and Fieldin’s experienced team handles setup and onboarding to ensure success from day one.
Though designed with Hull Split in mind, Remote Flow Monitoring delivers value across every spray event—from post-harvest cleanups to nutrient applications—making it a lasting investment in operational excellence.
“We built this for real-world challenges,” Birger explains. “Growers need control and clarity, not complexity. That’s what we deliver.”
Special Promotion for Hull Split Season
To help new customers prepare for the Hull Split window, Fieldin is offering limited-time introductory pricing for its Remote Flow Monitoring solution.
“This tool pays for itself quickly when you factor in the cost of a missed spray,” Birger says. “We’re here to make sure growers don’t have to take that risk.”
To learn more or schedule a demo, visit fieldin.com.
Follow Fieldin for more updates and in-season spray management tips: LinkedIn | Instagram | YouTube
Late in 2023, California almond growers – responsible for a crop valued at $3.88 billion in 2023 – started to hear about a potentially devastating new pest, the carpophilus beetle (Carpophilus truncatus).
With virtually no information about this species in California, Jhalendra Rijal and his colleagues spent 2024 investigating its extent in the almond-growing regions of the state and learning from peers in Australia, where the insect has been a persistent scourge for a decade.
A hullsplit almond showing a large number of carpophilus beetles (Carpophilus truncatus). Photo by Jhalendra Rijal.
“This year, we at least have the one year of experience with this pest, and we have generated information that is relevant and practical for the growers,” said Rijal, a University of California Cooperative Extension integrated pest management advisor. For example: After an insecticide trial was largely ineffective (likely because the beetle spends most of its life cycle protected within the nut), Rijal has been emphasizing cultural practices like orchard sanitation.
Sharing those crucial updates is one reason why the annual UCCE North San Joaquin Valley Almond Day is essential for growers, industry professionals and pest control advisers. This year’s event was held on Jan. 21 at the Modesto Centre Plaza.
During Almond Day 2025, Jhalendra Rijal, UCCE IPM advisor, discusses the differences between Carpophilus truncatus and related beetle species. Photo by Mike Hsu
“It’s the meeting on everyone’s calendar,” said Rijal, who co-organized the event alongside his UC Agriculture and Natural Resources peers, Brent Holtz and Cameron Zuber.
With support from Farm Credit, the 2025 Almond Day attracted about 140 people, who heard about a range of best practices on almond production and pest management from six UC experts.
“This is a great educational tool,” said meeting attendee Ali Arshad, a Blue Diamond grower who operates several ranches in San Joaquin and Stanislaus counties. “I like to come attend their seminars as much as possible; they’re very educational and informative – and very helpful too.”
Scientists offer advice on managing carpophilus beetle, red leaf blotch in almonds
Fellow grower Donny Hicks, who has attended 14 Almond Day meetings, concurred about the usefulness of the event. “Everything that was covered today is applicable to what I do,” he said.
Troubled by the presence of Carpophilus truncatus on his orchard in Hughson, Stanislaus County, Hicks said he recently partnered with Rijal to set some traps on his property, hoping to grow scientists’ understanding of the pest.
“It takes growers to help advance that knowledge and be the ‘guinea pigs’ somewhat,” Hicks explained. “At the same time, if it helps us growers as a whole, that’s a good thing.”
During his opening talk, Rijal reiterated the need for growers to clean up the remnant “mummy” nuts on the ground that serve as overwintering habitat and a food source for the next generation of beetles in the spring.
“Do the sanitation so you can destroy the population from the beginning and you will have less of a problem,” said Rijal, who also shared a visual ID guide that can help growers identify the specific pest in their orchard and thus better target their control methods.
Growers also heard practical advice on an emerging almond disease, red leaf blotch, caused by the fungus Polystigma amygdalinum. Named for the orange-red patches of discoloration on leaves, red leaf blotch in almond has led to significant crop loss across Mediterranean countries. Unknown in California prior to last year, there was an explosion of reports throughout the San Joaquin Valley during 2024.
“It was pretty surprising, both the quickness and vastness of the spread,” said Alejandro Hernandez-Rosas, a UC Davis Ph.D. candidate in the lab of Florent Trouillas, UC Cooperative Extension specialist in the Department of Plant Pathology at UC Davis.
During his presentation, Hernandez-Rosas said a preventative application of fungicide at petal fall – and then again at two and five weeks after petal fall – appear to work best to manage this disease. Fungicide applications made after the blotchy leaf symptoms appear will not be effective, Hernandez-Rosas said, and further research needs to be done to determine the most effective products and optimal timing for growers to make the most of their applications.
And because leaf litter is the “primary source” of the disease inoculum, Hernandez-Rosas added that cultural practices focused on speeding cleanup or decomposition of leaf litter are critical to reduce disease severity. However, it is only effective if done over a wide area in conjunction with neighbors.
Advanced symptoms of red leaf blotch (RLB) include large, yellow-orange blotches (roughly 1/2″) that turn reddish-brown in their center. Photo credit: Alejandro Hernandez and Florent Trouillas
Rodents, irrigation, replanting and whole orchard recycling
Both Arshad and Hicks mentioned that they intend to tackle the gopher problem in their orchards.
“I plant a cover crop every year and the gophers tend to really like it – so I get overrun with those gophers,” Hicks explained. “I’m trying to find that balance of not letting them overtake my orchard but still being able to cover crop – because that’s beneficial too.”
With many growers voicing a desire to learn about burrowing rodents, Almond Day organizers were pleased to schedule a presentation by Roger Baldwin, professor of Cooperative Extension in the Department of Wildlife, Fish and Conservation Biology at UC Davis.
Baldwin presented the available control options for not only pocket gophers but also ground squirrels and meadow voles. He stressed the need to understand the biology and ecology of the rodents to maximize efficacy; for example, whereas ground squirrels prefer green foliage as their main food source in the spring, they switch to seeds in the summer/fall – which would thus be a better time to use pelletized baits.
In choosing from baiting, trapping, habitat modification, burrow fumigation, biocontrols and other options, Baldwin recommended combining different strategies and approaches in an integrated way.
“Mixing and matching tools will give you the best possible results,” he said.
The utility of combining methods was also a key takeaway from the presentation by Moneim Mohamed, UCCE irrigation and soils advisor. Highlighting the latest tools and innovations, Mohamed outlined the soil-based, weather-based and plant-based methods to collect data that can help growers make the most of their water.
Mohamed said using even just one approach is beneficial in optimizing irrigation scheduling – but more is even better. “A combination of the three methods is the best,” he said.
Cameron Zuber, UCCE orchard crops farm advisor for Merced County, discussed considerations related to replanting an orchard, including field and soil conditions and the management of plant-parasitic nematodes and aggressive pathogens and pests. He also encouraged attendees to visit growingthevalleypodcast.com for more information on tree nuts and a host of other topics.
Finally, Brent Holtz, UCCE orchard systems farm advisor for San Joaquin County and a trailblazer for whole orchard recycling, presented an overview of WOR. He then shared recent findings on its effects on fungal pathogens, and ways to mitigate drawbacks of WOR – such as the initial carbon-to-nitrogen imbalance when the recycled almond wood chips are first spread on a field.
Hicks, who has already tried WOR in his orchard, is also the grower relations manager for RPAC, a Los Banos-based company that grows, processes and markets almonds. Hicks said he also brings what he learns during Almond Day to his fellow growers – illustrating the multiplier effect of such educational events.
“I have growers who possibly will be doing whole orchard recycling, and I can share that information,” Hicks said.
UC Agriculture and Natural Resources brings UC information and practices to all 58 California counties. Through research and Cooperative Extension in agriculture, natural resources, nutrition, economic and youth development, our mission is to improve the lives of all Californians. Learn more at ucanr.edu.
Almond growers are all too familiar with the challenges posed by pests in their orchards. Despite not being on the top of a grower’s concern list, spider mites can inflict serious damage to an almond orchard, and rather quickly if populations get out of control. However, effective monitoring and the use of beneficial insects can play a crucial role in managing these pests and ensuring a healthy almond harvest.
Understanding Spider Mites
Spider mites are tiny arachnids that thrive in warm, dry conditions, making almond orchards an ideal habitat. These pests feed on the leaves of almond trees, causing stippling, yellowing, and eventually leaf drop. Severe infestations can lead to reduced photosynthesis, weakened trees, and lower yields. Therefore, it is essential to keep a close eye on spider mite populations and take timely action to prevent economic losses.
The Role of Beneficial Insects
One of the most effective natural treatments for spider mites is the use of beneficial insects, such as six-spotted thrips. These tiny predators feed on spider mites and can significantly reduce their populations. David Haviland, a University of California Cooperative Extension (UCCE) entomology farm advisor, emphasizes the importance of relying on six-spotted thrips for mite management. These thrips are highly adaptable, reproduce quickly, and provide numerous operational benefits. They occur naturally, are free, and do not leave residues, pre-harvest intervals, or worker safety issues to worry about.
In addition to six-spotted thrips, other natural enemies of spider mites include predatory mites and lady beetles. These beneficial insects can help maintain a balance in the orchard ecosystem, reducing the need for chemical interventions. However, it is crucial to monitor the populations of both spider mites and their natural enemies to make informed decisions about pest management.
Effective Monitoring Techniques
Monitoring for spider mites involves regular inspections of the orchard, particularly in dusty or water-stressed areas where mites are most likely to thrive. Checking on the underside of leaves for the presence of spider mites is the most effective way to identify them in the orchard. According to the University of California Agriculture and Natural Resources (UC ANR) Integrated Pest Management (IPM) Program, growers should check for spider mites at least weekly during the warmer months. Presence-absence leaf sampling is a useful tool for determining whether treatment is necessary. If there are 1.4 mites per leaf or 38% of leaves are infested, it is time to consider intervention to prevent the population from reaching damaging levels.
To-Do List for Growers
Seasonal Monitoring: From March to early May, monitor orchards for both predators and spider mites at least once every two weeks. Increase monitoring frequency to at least once a week from June to September when mite populations can rapidly increase.
Weekly Inspections: Regularly inspect your orchard, especially in dusty or water-stressed areas, to check for spider mites. Use a hand lens to detect mite eggs, hatched spider mites, and predators.
Presence-Absence Leaf Sampling: Use this method to determine if treatment is necessary. If there are 1.4 mites per leaf or 38% of leaves are infested, take action.
Monitor Beneficial Insects: Assess the populations of natural enemies like six-spotted thrips, predatory mites, and lady beetles to ensure they are sufficient to control spider mites.
Consider Selective Miticides: If natural predators are not enough, consider using selective miticides that are less harmful to beneficial insects.
Follow ABC Guidelines: Utilize resources and guidelines provided by the Almond Board of California (ABC) for effective mite management.
For more detailed information on monitoring spider mites, growers can refer to the guidelines provided by the UC ANR IPM Program here.
Spider mites could pose a significant threat to almond orchards, but effective monitoring and the use of beneficial insects can help manage these pests without increasing inputs. By relying on natural predators like six-spotted thrips and other beneficial insects, growers can reduce the need for chemical interventions, lower costs and promote a healthier orchard ecosystem. — By the Almond Board of California
The carpophilus beetle, a serious pest threatening California’s almond industry, is officially documented in only four counties — Stanislaus, Merced, Madera, and Kings. However, according to entomologists and industry experts, its presence is far more widespread, raising concerns about the limitations of official reporting and its impact on securing resources for control and mitigation.
Houston Wilson, a Cooperative Extension specialist in the Department of Entomology at UC Riverside, has been surveying reports and conducting research on the beetle in collaboration with other UC and USDA researchers. “We’ve identified infested orchards — both almonds and pistachios — from every county within the San Joaquin Valley,” Wilson said. “We’re also hearing reports of crop damage from the Sacramento Valley (Sacramento through Butte County), but we have yet to directly confirm it there due to limited survey efforts.”
The Importance of Official Documentation
Despite mounting evidence of the carpophilus beetle’s spread, official state records remain limited. Wilson explains that for a find to be considered “official,” the county Agricultural Commissioner must collect a sample and submit it to the California Department of Food and Agriculture (CDFA) for verification. The current process means that many beetle infestations, though identified by researchers, remain unofficial.
“While we have unofficial records from our survey efforts, my understanding is that the official records only reflect what has gone through the CDFA process,” Wilson said.
For growers, the discrepancy between unofficial and official findings is more than just a technicality — it could also affect the allocation of resources. According to the Almond Alliance, securing state and federal assistance depends on having documented proof of the beetle’s widespread presence.
“The widespread documentation of the carpophilus beetle serves as a vital indicator of the extent and severity of the issue,” said Almond Alliance CEO Alexi Rodriguez. “When more counties report official beetle findings, it underscores the pervasive nature of the problem, highlighting its impact beyond isolated areas.”
Challenges in Reporting
Wilson acknowledges that the reporting process can be complicated, but he and his team actively assist growers. “If a grower contacts me about suspected beetle damage, I usually visit the farm to assess the situation,” he said. “If we confirm the presence of the carpophilus beetle in a county that hasn’t had an official report, we advise them to contact their Agricultural Commissioner and guide them through the reporting process.”
Rodriguez recognizes the difficulties growers face in reporting. “I want to acknowledge that the reporting process is not easy; however, expanding the network of official findings will allow us to advocate for more effective solutions by highlighting the problem’s regional and national significance,” she said.
Identifying the Carpophilus Beetle
For growers looking to detect the beetle, Wilson advises examining nuts in windrows, where nuts can be easily sampled. “The most apparent sign is a fine, powdery white frass on the nut, which results from beetle larvae tunneling into the kernel,” he said. “If you blow that frass away, you might see a circular hole in the shell where the adult beetle chewed through to lay its eggs. Inside, the larvae create distinctive oval-shaped tunnels in the kernel itself.”
Wilson is part of a team that last year developed a pest identification guide to help growers differentiate carpophilus beetle damage from other pests, such as navel orangeworm or ants.
Securing Support for Growers
To address the growing concern, the Almond Alliance continues to work with officials at both the state and federal levels. “This engagement is expected to lead to more coordinated and robust interventions, mobilizing the necessary support and funding to mitigate the impact of beetle infestations on ecosystems, agriculture, and local economies,” Rodriguez said.
Meanwhile, research efforts continue. “We’ve secured funding from the Almond Board of California and the California Pistachio Research Board for a second year, and we’ve now leveraged that into a larger pool of funding from the USDA,” Wilson said.
Growers can also take advantage of upcoming pest identification workshops organized by the Almond Board of California in March, where they can learn more about identifying carpophilus beetle damage.
A Call to Action
With the evidence pointing to a much wider distribution of the carpophilus beetle than official records reflect, the push for more growers to report infestations is crucial. “If we don’t have official documentation, we can’t make the case for more resources,” Rodriguez emphasized. “We urge growers to work with their local Agricultural Commissioners to ensure the beetle’s spread is formally recognized.”
By increasing official reports, the almond industry can strengthen its efforts to combat the carpophilus beetle, securing the necessary funding and support to protect California’s valuable almond crops.— By the Almond Board of California
Losing crops is a reality of farming, especially when you’re battling weather, new pests and emerging diseases. Seeing a few acres of your life’s work perish is tough, but the threat of losing your entire operation is a different type of sting. One California almond grower shares how soil health improvements made his orchards vulnerable to disease and how he was able to bring them back from the brink of total devastation.
Trees Lost to Unusually Wet Weather Worsened by Soil Prep
Whole orchard recycling is a process to reincorporate an outgoing orchard in preparation for planting a new one. Mature trees are felled and ground into woodchips, which are then spread and incorporated into the soil. The University of California found that this process can help improve water retention. The issue for John Fassler, a California pest advisor who went through whole orchard recycling, was that the moist soil and greater-than-normal rainfall turned his orchards into the perfect breeding ground for oomycete pathogens like Phytophthora.
Fassler has consulted at Braden Farms where they used whole orchard recycling as a way to prepare for planting a new orchard. “This is a fairly new process, which means we’re learning as we go,” he says. “Some issues we’ve seen have been a rise in fungal diseases, such as Phytophthora and other replant diseases.”
Mother Nature hasn’t helped the fungal disease risk, especially at the beginning of the 2023 growing season. California experienced greater than average annual precipitation in 2023, breaking numerous records and ending three years of persistent drought, according to the California Nevada River Forecast Center.
“We’ve had significant rainfall in California the last two years, so this has really intensified the battle with Phytophthora in some spots,” says Ashley Bandoni, Syngenta sales representative and California almond grower.
Fassler experienced devastation due to those heavy rains. One of his orchards was completely submerged, worsening the orchard’s Phytophthora issues.
“We lost about 500 trees on this block due to Phytophthora and replant disease,” says Fassler. “Phytophthora is becoming more and more of an issue in these wetter years.”
Many California growers and crop consultants have been battling fungal disease challenges.
Ethan Nicol, an independent pest control advisor and crop consultant for Balanced Agronomics, helped one of his customers manage extreme Phytophthora in a young almond orchard.
Planted in the fall of 2021, Nicol began seeing early symptoms of Phytophthora infections the following spring. Young trees like the ones in the orchard Nicol manages tend to be more susceptible to disease because their root systems and crown areas are smaller compared to those of mature trees, according to the University of California Department of Agriculture.
“In that first 2022 season, we observed maybe 30 percent of the orchard was infected,” says Nicol. “By mid-August, we had really grown to realize the significance of the issue.”
For both Nicol and Fassler, almond yield potential was on the line and devastation was just over the horizon. They both had a tough decision to make.
“As far as doing our research going into it, usually we have the Syngenta reps come in to help us decide if the product will be a good fit for us,” says Fassler. “We also ask about how the product differentiates itself from what we’ve already been doing.”
After discussions with their local Syngenta experts, Fassler and Nicol decided to apply Orondis® fungicide to help save their orchards. Fassler says his flooded orchard plot turned around.
“My experience with Orondis changed up our program,” says Fassler. “We’ve been able to work it into our program really well and we didn’t lose one tree this year.”
Nicol’s experience with Orondis was also nothing short of extraordinary. Before application, Nicol was working with the grower to continuously remove and replant dead trees. They lost roughly 600 almond trees — six ranches — to Phytophthora. Once Orondis was applied in 2023, Nicol observed a noticeable decline in newly infected trees.
“We were confident in the success that we were seeing by the replants taking and growing strongly, and the existing trees continuing to grow and not develop signs of Phytophthora,” says Nicol. “Going into 2024, just as a precaution and to help protect this investment, we made an additional Orondis application. There’s been almost no sign of infected trees this season.”
Growers Also Need Care
If Fassler and Nicol didn’t have the guidance and support of their Syngenta representatives, their almond orchards might have been lost.
“I’ve worked with Syngenta for probably about the last 20 years, and through the years we’ve had many different experiences,” says Fassler. “Syngenta has always been there to help us through and guide us through what needed to be done.”
While the hazelnut breeding program at Oregon State University has done a phenomenal job developing new tasty hazelnut varieties with disease resistance and other favorable characteristics that has made growing the crop easier in the Pacific Northwest, these varieties may have some setbacks as well. It seems that not only growers and consumers are enjoying these new varieties, but an invasive pest known as brown marmorated stink bug has also taken a particular fondness of these new varieties. Watch this video interview with Oregon State University Entomologist Vaughn Walton as he discusses the issue with Matthew Malcolm at the Nut Growers Society Winter Meeting. Read more about it in Pacific Nut Producer Magazine. Don’t currently receive the magazine? Subscribe for free at: https://malcolmmedia.com/subscribe/
The California Association of Pest Control Advisers (CAPCA) recently gathered for their 50th annual conference. Bringing together a bright group pest control advisors tasked with protecting the most diverse agricultural landscape in the nation, watch this special video presentation highlighting what CAPCA is all about and what it means to be a member of this organization as they celebrate this milestone year.
