Weekly Tree Nut Report: Red Leaf Blotch Across Sac Valley, Carpophilus in Walnuts, Fresno Pistachios

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This week’s priority: map what your orchards will carry into winter. A UCCE advisor reports red leaf blotch throughout the northern Sacramento Valley,¹ and a UC IPM survey found the invasive carpophilus beetle in floor nuts from a well-managed Sacramento Valley walnut block.² Navel orangeworm development has nearly stopped at all four gauge stations, and orchard water use is falling.^{4, 6} No October shipment reports were out by our cutoff, so the market board is carried forward.

This week in numbers

• $1.22B: Fresno County’s 2025 pistachio value, now its No. 2 crop behind almonds⁷
• 4: Sacramento Valley orchards where survey traps caught carpophilus beetle: two almond, two pistachio²
• 0.30″: Almond water use expected this week at four south Sacramento Valley stations⁶

For PCAs: Pest, Weed and Disease Management

1. Almonds: red leaf blotch now reported across the northern Sacramento Valley

New this week · UCCE, Northern Sacramento Valley, Nov 9, 2026

Red leaf blotch, a foliar disease of almonds first identified in California in 2024 in the northern San Joaquin Valley, was first detected in the Sacramento Valley in 2025 and has now been reported throughout the region covered by UCCE orchards advisor Jaime Ott (Tehama, Shasta, Glenn and Butte counties). Ott writes that it will likely become a significant disease in California almonds.¹

The fungus overwinters on fallen leaves. Spring rains, from about late February through late April, release spores that infect newly emerging leaves, but symptoms don’t show until late April or May, and leaves curl and drop by June and July. Unlike rust, there is no reinfection during the season; all of a year’s infections are set in spring, so Ott notes that control is preventive only.¹

Next step: Before leaf drop finishes, map which blocks showed symptoms in 2026 and how heavily, and note blocks with heavy leaf litter and low, wet spots. Hand the map to the PCA who writes the 2027 disease program; any material choice belongs to that PCA and the label. Deliverable: a red leaf blotch history map by block.

Source: UCCE: Red leaf blotch update

2. Walnuts, almonds and pistachios: carpophilus beetle turns up in a Sacramento Valley walnut block

Recent update · UC IPM, Sacramento Valley, Nov 2, 2026

UC IPM advisor Sudan Gyawaly reports that statewide survey traps confirmed Carpophilus truncatus in two almond and two pistachio orchards in the Sacramento Valley, without widespread damage so far. Samples sent in by PCAs and consultants also turned up beetles and larvae in walnuts collected from the orchard floor of a well-managed Chandler block in the region. The beetle, which averages 2–5% damage in Australian almonds, was first found in San Joaquin Valley almonds and pistachios in 2023, and in a Stanislaus County walnut block the same year.²

Adults overwinter in mummy nuts, mostly on the ground, so Gyawaly calls sanitation, shredding or destroying ground nuts, critical; in UC studies, insecticides have given limited control so far. The damage is easy to confuse with navel orangeworm: worm feeding leaves brown frass with heavy webbing, while carpophilus leaves a fine powder with little webbing.²

Next step: When you take winter mummy samples, crack ground nuts as well as tree nuts, walnut blocks included, and sort damage by frass type. Send suspect beetles or larvae to your UCCE or UC IPM advisor for identification. Deliverable: a mummy-sample log by block that separates navel orangeworm from carpophilus-type damage.

Source: UC IPM: Updates on invasive carpophilus beetle in the Sacramento Valley

3. Pistachios, statewide: get mummies out before the rains

Seasonal reminder · UC IPM, text updated June 2019

UC IPM’s pistachio guideline calls orchard sanitation key to cutting navel orangeworm’s overwintering survival: after harvest, remove unharvested nuts from trees and the ground, including nuts lodged in tree crotches, blow the berms, and destroy the nuts by discing or flailing. Moisture helps fungi break down the kernels, which is why the guideline advises getting mummies out as soon as possible after harvest, before rain. Poorly timed or poorly run harvests leave more mummies on the trees to carry the pest into next year.³

Next step: Walk each block after the last shake and count mummies left in trees and on berms, flagging rows the harvest missed. Record which blocks are finished and which still need work, and schedule the rest before the wettest weeks. Deliverable: a post-harvest mummy count and sanitation schedule by block.

Source: UC IPM: Navel orangeworm in pistachio

Pest pressure gauge: navel orangeworm

Degree-days for Nov 3–Nov 9, UC IPM model thresholds, NOAA station data.^{4, 5}

● Green Oroville, Sacramento Valley: 31 degree-days, development nearly stopped

● Green Modesto, northern San Joaquin Valley: 38 degree-days, development nearly stopped

● Green Fresno, central San Joaquin Valley: 43 degree-days, development nearly stopped

● Green Bakersfield, southern San Joaquin Valley: 46 degree-days, development nearly stopped

JCS gauge of how fast navel orangeworm can develop at last week’s temperatures: green under 50 degree-days a week, yellow 50–119, red 120 or more. It is not a trap count; your own traps and mummy counts tell you what is in the orchard.

For CCAs: Water and the Season’s Numbers

4. Almonds, pistachios and walnuts, south Sacramento Valley: orchard water use drops toward winter

New this week · UCCE Sacramento Valley Orchards, Nov 6, 2026

The weekly ET report for the CIMIS stations at Woodland, Davis, Staten Island and Verona put almond water use at 0.41 to 0.44 inch for Oct 30–Nov 6, with about 0.30 inch expected the following week. Pistachios used 0.25 to 0.27 inch and walnuts 0.24 to 0.26. Seasonal almond use since Feb 24 reached 45.47 to 48.10 inches across the four stations, and rain for the week ranged from 0.07 inch at Staten Island to 0.42 inch at Davis. Cover-cropped orchards can lose up to 25% more soil moisture a week than the estimates show.⁶

Next step: Total the water each block received this season and set it beside the nearest station’s seasonal ET, adjusted for system efficiency (the report gives 80–95% for drip, 80–90% for micro-sprinklers). Flag blocks that went into fall short of demand and blocks where rain now covers the small remaining use. Deliverable: a 2026 water-balance sheet for each block.

Source: UCCE: Current South Sac Valley ET report, Nov 6

5. Pistachios and almonds, Fresno County: pistachios become the county’s No. 2 crop

New this week · KMPH FOX26, Fresno County, Nov 3, 2026

Fresno County’s 2025 crop and livestock report, presented Nov 3, values pistachios at $1,218,870,000, moving them past grapes ($1,032,871,000) into second place. Almonds led for the second year in a row at $1,751,026,000. The county’s total gross value reached a record $9,642,283,000, up 6.8% from 2024, and Fresno again ranked as the top agricultural county in California and the nation.⁷ These are gross production values for the 2025 crop, not grower returns.

Next step: When the full county report is posted, set your clients’ 2025 yields by block beside the county’s acreage and yield figures for pistachios and almonds to see which blocks ran above or below the county. Deliverable: a one-page 2025 yield benchmark for each client.

Source: KMPH: Fresno County agriculture hits record $9.64B in 2025

Market board: Almond, Pistachio and Walnut Shipments

All figures carried forward · October reports due

Almonds Aug–Sept 2026 · carried forward	422.64 million kernel-weight pounds shipped, up 19% from 355.06 million in the same months of 2025; receipts reached 1.22 billion pounds.8
Pistachios September 2026 · carried forward	88.42 million total reported product pounds shipped, versus 63.08 million in September 2025.9
Walnuts 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 board had posted an October report by our research cutoff, so every row is carried forward from last week’s edition. Shipments measure movement, not grower returns. The Almond Board posts its October position report on Nov 12.^8–11

Next step: When the October reports land, compare each crop’s shipment pace with your clients’ deliveries and settlement timing; a faster pace is not a price.

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

From West Coast Nut magazine

What I Want to Know After Harvest

By Gary Osteen · October 28, 2026

How to read damage samples, nut weights, leftover weeds and postharvest water by block before planning next season, and why stretched-out work windows let navel orangeworm in even where mummy removal was good.

Read the article · Browse the latest issue

Coming week watchlist

Nov 12 Almonds, statewide: October position report from the Almond Board; set it beside September’s shipments.¹¹

Nov 12 Walnuts: the California Walnut Board and Commission hold their joint board meeting, 10 a.m., Rancho Cordova.¹²

Nov 12 All three crops, statewide: NOAA’s monthly El Niño update, worth reading for winter rain and orchard access.¹³

Mid-Nov Pistachios: the October inventory and shipment report; September’s came out Oct 15.⁹

Dec 8–10 Almonds: The Almond Conference at the SAFE Credit Union Convention Center; registration is free.¹⁴

Rules, comment deadlines and agency actions are in Tuesday’s Reg Watch

Your next moves

Scout blocks that showed red leaf blotch in 2026 and map them before leaf drop finishes, from item 01, this month. UCCE

Scout ground mummies as well as tree mummies for the fine, powdery frass of carpophilus beetle, walnut blocks included, from item 02, this month. UC IPM

Watch for NOAA’s El Niño update on Nov 12 and finish pistachio mummy removal before the wettest weeks, from item 03. NOAA

Editorial suggestions for field review, never a pesticide or product recommendation. In California only a licensed PCA can make a written pesticide recommendation.

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, “Red Leaf Blotch update, September 2026,” posted November 9, 2026.
2. Sudan Gyawaly, UC IPM, Sacramento Valley Orchards, “Updates on invasive carpophilus beetle in the Sacramento Valley,” November 2, 2026.
3. UC Statewide IPM Program, “Navel Orangeworm,” Pistachio Pest Management Guidelines, updated June 2019.
4. NOAA Regional Climate Centers, “Applied Climate Information System (ACIS),” daily temperatures for Oroville, Modesto, Fresno and Bakersfield, November 3–9, 2026.
5. UC Statewide IPM Program, “Navel orangeworm degree-day model,” (55°F and 93.9°F thresholds).
6. Sacramento Valley Orchards (UCCE), “Current South Sac Valley ET Report: November 6, 2026,” week of October 30–November 6, 2026.
7. KMPH FOX26, “Fresno County agriculture hits record $9.64B in 2025, up 6.8% from 2024,” November 3, 2026.
8. Almond Board of California, “Almond Industry Position Report, September 2026,” October 13, 2026, p. 1.
9. Administrative Committee for Pistachios, “September 2026 Inventory Shipment Report (Pounds),” October 15, 2026, p. 1.
10. California Walnut Board, “Monthly Shipment Report, September 2026,” October 8, 2026, p. 1.
11. Almond Board of California, “Position Report Release Schedule,” updated October 2026.
12. California Walnut Board and California Walnut Commission, “Board of Directors’ Joint Meeting agenda, November 12, 2026,” posted October 29, 2026.
13. NOAA Climate Prediction Center, “ENSO Diagnostic Discussion,” next issue scheduled November 12, 2026.
14. Almond Board of California, “The Almond Conference 2026: Registration,” December 8–10, 2026.
15. Photos: item 05, Scott Bauer, USDA Agricultural Research Service (public domain).