Weekly Tree Nut Report: Wet-Winter Phytophthora Prep, Eyewash Comments by Nov 5, Smaller Walnut Crop

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Research through October 30, 2026, 10:05 a.m. PT. This week’s priority: get blocks and records ready for a wet winter. It was a quiet week for new tree nut findings, so the lead is UCCE’s Oct 26 checklist for telling Phytophthora from waterlogging,¹ followed by DPR’s proposed eyewash rules, open for comment until Nov 5.³ The other briefs apply clearly dated UC guidance and research to dormant-season decisions on spur sampling, bee stocking and winter chill.^2,4,5 In the market, USDA’s first 2026 walnut forecast is 16% below last year’s crop.⁷

This week in numbers

• 24 hrs: Soil saturation most Phytophthora species need before infection starts¹
• 20%: Infested almond spurs at which UC IPM’s dormant table drops “no spray” for scale or mite eggs²
• −16%: 2026 walnut forecast, 680,000 tons, vs. 809,000 in 2025⁷

For PCAs: Pest, Weed and Disease Management

1. Almonds: sort Phytophthora risk from waterlogging before a wet winter

New this week · UCCE Sacramento Valley, Oct 26, 2026

UCCE orchard advisor Jaime Ott (Tehama, Shasta, Glenn and Butte counties) posted a wet-winter checklist on Oct 26, citing a September outlook for normal rain in October and November and very high rainfall from December through February. New since our Oct 28 crown-rot brief: it separates two look-alike problems. Most Phytophthora species need at least 24 hours of saturated or flooded soil to infect, and dormant trees are much less susceptible, so winter flooding is less worrying than spring flooding. Waterlogging is root suffocation, not disease: it takes days to weeks, is worst on heavy, compacted or hardpan soils, and leaves no gumming or sharp canker edge.¹

Trees up to 3 or 4 years old are most at risk. For aerial Phytophthora, cankers stop expanding above 73°F and unprotected pruning wounds stay susceptible for up to 4 weeks, so the article advises pruning in dry weather, with no rain in the 10-day forecast. Recovery from prolonged saturation can take a year or two.¹

Next step: Before the first big storm, check ditches, culverts and drain tiles, and map blocks that flooded in 2023, sit on heavy or hardpan soil, or are 4 years old or younger. Start a flood log (start date, area, duration, first symptoms) so spring decisions rest on documented saturation, not the season’s rain total. Products named in the article are illustrations; current labels govern. Deliverable: a wet-winter risk map and flood log for each ranch.

Source: UCCE: Phytophthora and waterlogging considerations for a very wet winter

2. Almonds: schedule dormant spur samples for scale and mite eggs

Seasonal reminder · UC IPM, text updated Aug 2017

UC IPM’s almond guidelines call for one dormant spur sample a year, between mid-November and the end of January. Randomly pick 35 to 50 trees per orchard, clip 2 or 3 spurs from inside each canopy, and include wood at least 2 years old so parasite activity shows. Record only whether each spur has San Jose scale, European fruit lecanium, or European red or brown mite eggs; scab is checked separately on first-year twigs.²

Thresholds are percentages of infested spurs: below 20% for either scale or for mite eggs, the table lists no spray, and the two scales are never added together. A hole in a San Jose scale cover or a blackened lecanium means parasitism; where it is common, UC IPM advises sparing parasites during the season. Dormant oil alone does not adequately control European red mite in Kern County.²

Next step: Give every almond block a sampling date and a reader. Keep each scale species, mite eggs and parasitism in separate columns on UC IPM’s form, and file each result with the dormant decision it supports, including a documented no-spray call. Deliverable: a block-by-block spur record with the treat or no-treat decision.

Source: UC IPM: dormant spur sampling and treatment guidelines for almond

3. All three crops, statewide: comment on DPR’s eyewash rules by Nov 5

Recent update · DPR, Oct 20, 2026

DPR’s proposed package (DPR 26-005, released Sept 18) would require an eyewash station meeting ANSI Z358.1-2014, which includes hands-free flow once activated, when labeling requires mixers and loaders or liquid-fumigant handlers to wear protective eyewear, or when a closed system is used. Anyone handling a product whose label requires protective eyewear would also need access to a personal eyewash unit holding at least one pint of fluid.³

A separate change, a decontamination site within 100 feet of mixing and loading regardless of signal word, covers non-production uses such as landscape and rights-of-way work, not commercial orchards. DPR estimates an ANSI station at $338 on average and a personal unit at about $14. Its virtual hearing is Nov 5 at 1:30 p.m., and written comments close that day. The rules are proposed, not adopted.³

Next step: List each client’s 2027 products whose labels require protective eyewear, then check every mix/load site and rig for a hands-free station and personal units. If the proposal creates a practical problem for an operation, comment by Nov 5. Deliverable: an eyewash inventory by site and rig, with gaps priced.

Source: DPR 26-005: pesticide decontamination sites (proposed regulation)

For CCAs: Bloom Planning: Bees and Chill

4. Almonds: price the bees for self-fertile Independence blocks

Research to apply · Almond Board, Oct 2, 2026 (UC Davis trial, 2020–21)

A two-year study led by UC Davis apiculture specialist Elina Niño, with USDA ARS, Olam and Beeflow and Almond Board support, tested whether self-fertile Independence still gains from rented hives in 2020 and 2021. Trees open to bees had significantly greater nut set than trees caged to keep bees out, carrying through to higher yields, though average kernel mass was slightly lower.⁴

In the second year, bee activity rose from zero to one hive per acre, but two hives did not significantly increase flower visits over one; neighboring orchards supplied an estimated half hive per acre. The article cites about $200 per hive against the usual two hives per acre for mature orchards. Niño called it a smaller-scale study, and newer self-fertile varieties such as Shasta were not tested.⁴

Next step: Before signing pollination contracts, list each Independence block’s 2026 stocking rate, set, yield and kernel weight, and note neighboring bee sources. Where a block runs two hives per acre, cost a one-hive option with a side-by-side harvest comparison; don’t extend the result to untested varieties. Deliverable: a block-level 2027 stocking plan with the cost difference.

Source: Almond Board: pollination still pays in self-fertile almond varieties

5. Pistachios: start a chill log for the 2027 bloom

Research to apply · UCCE Tulare County, Nov 2021

Handlers had received 645.75 million pounds of the short 2026 pistachio crop through Sept 30,⁸ after a record 1.6 billion pounds in 2025; Wonderful Pistachios’ Andy Anzaldo expects a 2027 rebound.⁶ UCCE Tulare County advisor Elizabeth Fichtner’s review notes that Peters males need at least 900 hours below 45°F for 50% bloom and Kerman 700 hours for 44% bloom; 900 hours is about 69 chill portions in the Central Valley. Low chill is linked to drawn-out bud break, poorly matched male and female bloom, more blanks and lower yield.⁵

Chill isn’t everything: statewide yields didn’t fall below average until chill dropped under 57 portions, and a 30-year study of three Kerman orchards tied over 65% of yield variation to prior-year yield, warm days (over 80°F) before bloom, and cool and warm temperatures from mid-November to mid-February. UC’s online chill calculators use CIMIS stations, which may not match an orchard’s microclimate.⁵

Next step: For each ranch, pick the nearest CIMIS station in UC’s chill calculator and log chill portions weekly, adding an in-orchard logger where fog or cold-air drainage makes the station a poor stand-in. Next spring, record Kerman and male bloom dates in the same file. Deliverable: a block chill log to read with 2027 bloom and set records.

Source: UCCE Tulare and Kings counties: winter chilling of pistachio (PDF)

Market snapshot: Smaller Crops, Faster Early Shipments

Walnut forecast and pistachio receipts new here · Shipment figures carried forward

USDA NASS’s Oct 1 forecast puts the 2026 California walnut crop at 680,000 tons, down 16%, on an average set of 796 nuts per tree versus 972 last year. County sets ranged from 510 in Stanislaus (856 in 2025) to 1,071 in Glenn (989). The forecast ran 12% below the final crop in 2025 and 10% above it in 2024.⁷

Walnut crop 2026 forecast · new here	680,000 tons, down 16% from 809,000 tons in 2025; 371,000 bearing acres (preliminary).7
Pistachio receipts 2026 crop through Sept 30 · new here	645.75 million pounds received by handlers (open inshell, closed shell and shelling stock).8
Pistachio shipments September 2026 · carried forward	88.42 million total reported pounds, versus 63.08 million in September 2025.8
Almonds August–September 2026 · carried forward	422.64 million kernel-weight pounds shipped, versus 355.06 million; receipts of 1.22 billion pounds, up 22.48%, against the report’s 2.7 billion-pound crop forecast.9
Walnut shipments September 2026 · carried forward	5,177 inshell short tons versus 2,509; 15,512 kernel short tons versus 9,461, compared with September 2025.10

No new monthly shipment reports came out in our research window, so shipment figures are carried forward; they measure movement, not grower returns. The Almond Board’s October position report is due Nov 12.^8–10

Next step: Set each walnut client’s 2026 block yields against the forecast’s county nut-set table before cutting 2027 budgets, to separate a regional short crop from block-level problems.

Sources: Walnut forecast (PDF) · Pistachio report (PDF) · Almond position report (PDF) · Walnut shipments (PDF)

From West Coast Nut magazine

2026 State of the Tree Nut Industry: Three Crops, Three Different Outlooks

By Kristin Platts · October 28, 2026

Leaders from Wonderful Pistachios, American Pistachio Growers, Blue Diamond, the Almond Board and the California Walnut Board size up a short pistachio crop, shrinking almond acreage and a smaller walnut crop with firmer prices, and the costs, water and competition all three share.

Read the article · Browse the latest issue

Coming week watchlist

Nov 5 All three crops, statewide: DPR’s virtual hearing on the proposed eyewash and decontamination rules, 1:30 p.m.; written comments close the same day.³

Through Nov 20 Almonds, statewide: USDA’s mail referendum on letting the Almond Board use a seasonal line of credit. Growers who produced almonds from Aug 2025 through July 2026 can vote; passage needs two-thirds of growers voting or of their volume.¹¹

Mid-Nov Almonds, all regions: UC IPM’s dormant spur sampling window opens and runs through January.²

Through Nov 30 All three crops, statewide: DPR takes comments on its draft 2025 annual report on the soil fumigant 1,3-D. CDFA voided about nine months of 2025 1,3-D air data after a lab reference standard degraded.¹²

What are you seeing?

What is your crop, county and biggest field concern? Email info@jcsmarketinginc.com and tell us.

Editorial note: “Next step” passages are West Coast Nut’s editorial recommendations; the findings before them are attributed to the numbered sources. Product mentions are not recommendations. Orchard-specific judgment, current product labels and applicable requirements govern management. This report does not award CE credit.

Sources

1. Jaime Ott, UCCE Tehama, Shasta, Glenn and Butte counties, Sacramento Valley Orchards, “Phytophthora and waterlogging considerations for a very wet winter,” October 26, 2026.
2. UC Statewide IPM Program, “Dormant Spur or First-Year Twig Sampling and Treatment Guidelines,” Almond Pest Management Guidelines, UC ANR Publication 3431, text updated August 2017.
3. California Department of Pesticide Regulation, “DPR 26-005: Pesticide Decontamination Sites” (Notice of Proposed Regulatory Action, September 18, 2026), and “Save the Date: Hearing on Proposed Eyewash and Decontamination Regulations,” October 20, 2026.
4. Almond Board of California, “Planning for Spring: Pollination Still Pays in Self-Fertile Almond Varieties,” October 2, 2026.
5. Elizabeth J. Fichtner, UCCE Tulare County, “Winter Chilling of Pistachio: Consequences of Low Chill and Implementation of Online Chill Calculators,” In a Nutshell (Tulare and Kings counties), November 2021, pp. 1–3.
6. Kristin Platts, West Coast Nut, “2026 State of the Tree Nut Industry: Three Crops, Three Different Outlooks,” October 28, 2026.
7. USDA National Agricultural Statistics Service, “2026 California Walnut Objective Measurement Report,” October 1, 2026, pp. 1–2.
8. Administrative Committee for Pistachios, “September 2026 Inventory Shipment Report (Pounds),” October 15, 2026, p. 1.
9. Almond Board of California, “Almond Industry Position Report, September 2026,” October 13, 2026, p. 1; and “Position Report Release Schedule,” updated October 2026.
10. California Walnut Board, “Monthly Shipment Report, September 2026,” October 8, 2026, pp. 1–2.
11. Almond Board of California, “Vote for Seasonal Line of Credit Authority,” October 30, 2026; USDA Agricultural Marketing Service, “Almonds Grown in California; Amendment to the Marketing Order,” Federal Register, October 8, 2026.
12. California Department of Pesticide Regulation, “DPR Releases Draft 2025 Annual Report on 1,3-D, Opens Public Comment Period,” October 16, 2026.
13. Photos: honey bee on an almond flower (item 04), Jeff Pettis, USDA ARS (public domain). Other photos licensed by JCS Marketing.