Growing the Valley

Self-Fertile Nonpareil: Sierra Gold (2025)

28 Sep 2025

Contributed by Lukas

Self-fertile Nonpareil has the potential to be a gamechanger for California almond growers. Both Sierra Gold Nursery (FruitionOne™) and Burchell Nur...

Self-Fertile Nonpareil: Burchell (2025)

28 Sep 2025

Contributed by Lukas

Self-fertile Nonpareil has the potential to be a gamechanger for California almond growers. Both Sierra Gold Nursery (FruitionOne™) and Burchell Nur...

Walnut Mold (2025)

27 Sep 2025

Contributed by Lukas

Dr. Themis Michailides (UC Davis Plant Pathologist at the Kearney Ag Center) provides a critical update on his lab’s research on the biology and man...

In a Water Scarce Future, How Should we Design Almond Orchards?

04 Sep 2025

Contributed by Lukas

Facing tightening SGMA regulations and the specter of future droughts, how should we be designing the almond orchard of the future? On the podcast, Fr...

Pulling Past Almond Irrigation Lessons Forward at the Nickels Soil Lab

03 Sep 2025

Contributed by Lukas

Researchers have been conducting almond irrigation and other studies at the Nickels Soil Lab in Arbuckle, CA for over 50 years! On the podcast, Franz ...

Almond Environmental Bud Failure / Monterey Leafing Failure (2025)

28 Aug 2025

Contributed by Lukas

Environmental bud failure showed up in almonds in a big way in 2025. From a subtle delay of leafing in parts of Nonpareil canopies throughout the Cent...

Almond Non-Infectious Bud Failure

27 Aug 2025

Contributed by Lukas

If you work in the almond industry, you likely know non-infectious bud failure (NBF) is bad news. However, do you understand why NBF happens, and that...

What is regenerative agriculture? With Amelie Gaudin

25 Aug 2025

Contributed by Lukas

Regenerative agriculture is currently all the rage these days in some circles. With a broad range of practices that can be classified as regenerative...

Walnut scale with Elizabeth Fichtner

20 Aug 2025

Contributed by Lukas

Walnut scale is a minute insect pest that can, if populations build high enough and kill fruiting wood. It can do this by directly allowing pathogens ...

Prunes: Fruit Growth through Postharvest

17 Aug 2025

Contributed by Lukas

A great deal goes into a successful prune crop. In part two or a two-part podcast on prune crop phenology we complete the yearly cycle by talking...

Prunes: From Buds through Fruit Thinning

17 Aug 2025

Contributed by Lukas

A great deal goes into a successful prune crop. In part one of a two-part panel, Franz Niederholzer (UCCE Colusa), Jaime Ott (UCCE Tehama), Becky Whee...

Oak Root Fungus with Roger Duncan (2025)

11 Aug 2025

Contributed by Lukas

.Oak root fungus (Armillaria root rot) is a devastating disease that can plague orchards generation after generation. Resistant rootstocks is the ans...

Warm Season Phytophthora in Almond with Jim Adaskaveg (2025)

04 Aug 2025

Contributed by Lukas

Phytophthora isn’t just an early season problem anymore. On this episode of the podcast, Dr. Jim Adaskveg (UC Riverside) talks warm season phytophth...

How do pistachio shells split? With Shuxiao Zhang and Georgia Drakakaki

14 Jul 2025

Contributed by Lukas

We know pistachios, and we love to eat them. Despite pistachio ice cream being the objectively best way to consume this nut , the majority of pistachi...

Managing Johnsongrass in Orchards with Ryan Hill (2025)

22 Jun 2025

Contributed by Lukas

Johnsongrass can be a tough weed to control. Ryan Hill (UCCE Tehama, Shasta, Glenn) comes on the podcast to update us on the integrated year-round man...

New Walnut Rootstocks (2025)

10 Jun 2025

Contributed by Lukas

Dr. Pat J. Brown (UC Davis) discusses exciting new clonal rootstocks being developed by a team of UC and USDA researchers. Pat is looking for growers ...

Leaffooted Plant Bug & Stink Bugs Part 2: Integrated Management (2025)

04 Jun 2025

Contributed by Lukas

Three PhD entomologists with UC Cooperative Extension: Sudan Gyawaly, Jhalendra Rijal, and Houston Wilson discuss integrated management of the leaff...

Leaffooted Plant Bug & Stink Bugs Part I: Phenology and Monitoring (2025)

27 May 2025

Contributed by Lukas

Three PhD entomologists with UC Cooperative Extension: Sudan Gyawaly, Jhalendra Rijal, and Houston Wilson discuss the phenology and monitoring of the ...

Gophers, Ground Squirrels, Voles, Roof Rats, and Deer Mice… Oh My! (2025)

25 Apr 2025

Contributed by Lukas

Dr. Roger Baldwin (UCCE Specialist in Human-Wildlife Conflict Resolution) discusses orchard management of pocket gophers, ground squirrels, voles (mea...

An Earlier Start to Irrigation in Almond (2025)

18 Apr 2025

Contributed by Lukas

Drs. Or Sperling (ARO-Volcani) and Maciej Zwieniecki (UC Davis) discuss their groundbreaking research on almond irrigation. That research has culminat...

Tree Destroyer: Cytospora in Prune (2025)

07 Apr 2025

Contributed by Lukas

Cytospora is a devastating fungal canker disease in California prune production. Themis Michailides (UC Davis at Kearney Ag Center) updates us on the ...

The effects of wildfire smoke on nut crops

04 Mar 2025

Contributed by Lukas

Fire is a fact of life in California, whether you live in a fire-prone area or you live in an area that can be impacted by smoke. Smoke doesn’t just...

Walnut Rest-Breaking Agents with Katherine Jarvis-Shean

19 Feb 2025

Contributed by Lukas

English/Persian walnuts have a fairly high chill requirement and can suffer from poor bud break and reduced yields in years with marginal or low chill...

Nonstructural carbohydrates, dormancy and bloom of tree nuts

12 Feb 2025

Contributed by Lukas

Nonstructural carbohydrates are the energy storage compound of trees. They are built from simpler sugars that are created via photosynthesis, and the ...

2025 Water Outlook with Sam Sandovol Solis

07 Feb 2025

Contributed by Lukas

Sam Sandovol Solis, professor of cooperative extension in water management at UC Davis, pulls out the crystal ball for the fourth time to predict what...

Tree nut production and water use outside of the United States

29 Jan 2025

Contributed by Lukas

Almonds and pistachios are native to arid climates and are drought tolerant tree species. In California however, the high cost of production and land ...

The Future of Irrigation with Tom Devol (2024)

28 Dec 2024

Contributed by Lukas

At a time when California orchard farmers are being challenged by poor economics and tightening regulations – coming irrigation advances promise lab...

Tree Destroyer: Phellinus in Prunes (2024)

16 Dec 2024

Contributed by Lukas

Phellinus heart rot in prune trees destroys structural integrity. Laurel Hoffman (UC Davis) updates us on the biology and management of this important...

Encore: Avocado orchard recovery after wildfire with Ben Faber

26 Nov 2024

Contributed by Lukas

We posted this episode back in 2020 and are pulling it out of the archives. It’s an interesting story of the surprising resilience of a tree after w...

Walnut Freeze: Remaining Vigilant

18 Nov 2024

Contributed by Lukas

Sudden autumn freeze events still sneak up on California walnut growers – as they did to some growers last Halloween (2023). Clarissa Reyes (UCCE Su...

Carpophilus truncatus update with Jhalendra Rijal

12 Nov 2024

Contributed by Lukas

It’s been a year since Carpophilus truncatus (Carpophilus beetle) was found in California. Jhalendra shares some research updates and observations w...

Almond Variety Trials 10 Years In

28 Oct 2024

Contributed by Lukas

Luke Milliron, Phoebe Gordon, and Roger Duncan discuss the three almond variety trials 10 years after they were planted across the Central Valley. Tha...

Nitrogen uptake of Golden Hills and Lost Hills

15 Oct 2024

Contributed by Lukas

Pistachios alternate bear, which changes the dynamics of nitrogen uptake and allocation within the tree on a year to year basis. To add to this, the n...

The Walnut Variety Trial and the Walnut Improvement Program

10 Oct 2024

Contributed by Lukas

A Third Thursday x Growing the Valley collab! Karla Caldera (CSUC graduate student) discusses the research she is conducting at the walnut variety tri...

Are we measuring chill incorrectly? With Giulia Marino

01 Oct 2024

Contributed by Lukas

Trying to predict when trees will come out of dormancy and whether they’ve stayed in dormancy for a long enough period of time is a very old science...

Encore: Potassium fertilization with Phoebe Gordon

24 Sep 2024

Contributed by Lukas

Phoebe breaks down the importance and best practices surrounding potassium nutrition in orchard crops. Phoebe and Franz Niederholzer wrote an excellen...

Isaya Kisekka on passive plant water status measurement devices

17 Sep 2024

Contributed by Lukas

Measuring plant water status is a critical but underused tool in irrigation management. It allows us to determine whether plants actually need water, ...

Prune Brownline Disease with Jaime Ott

02 Jul 2024

Contributed by Lukas

Jaime Ott discusses the resurgence of prune brownline in the northern Sacramento Valley. In addition to prune, Jaime reminds us to be on the lookout f...

Sterile Insect Technique update with Houston Wilson

26 Jun 2024

Contributed by Lukas

Houston Wilson, Professor of Cooperative Extension in entomology with UC Riverside, gives us our semi-yearly update on Sterile Insect Technique (SIT) ...

Why woodchip size may matter with whole orchard recycling

04 Jun 2024

Contributed by Lukas

Incorporating large amounts of woody biomass into soil, such as in whole orchard recycling (WOR), can promote carbon sequestration, nutrient recycling...

Encore: Sarah Light on Soil Health

28 May 2024

Contributed by Lukas

Soil health is broad term that encompasses a important topic: functional soil that can support human activities, animals, and plants. Measuring soil ...

Florent Trouillas on the 2023 aerial phytophthora outbreak in almonds

21 May 2024

Contributed by Lukas

In 2023 UCANR advisors and specialists got an unusual number of farm calls on branch cankers in almonds, many of which turned out to be aerial phytoph...

Monterey Almond Maladies

14 May 2024

Contributed by Lukas

Luke Milliron discusses the growing list of problems with the Monterey almond variety in the northern Sacramento Valley. Leafing failure (what is it) ...

Amisha Poret-Peterson on soil microbiome basics

16 Apr 2024

Contributed by Lukas

This week, we share an episode that was TWO YEARS IN THE MAKING (if you count continually rescheduling episode recording sessions due to various confl...

Encore: Lu Zhang on Dust During Pistachio Bloom

03 Apr 2024

Contributed by Lukas

Lu Zhang provides an update on work published last year on the effect of dust on pistachio pollen, flowers, nut set, and blanking (it’s not good!). ...

Daniele Zaccaria on cover crop research in pistachios

26 Mar 2024

Contributed by Lukas

Cover crops! They’re not just for almonds (despite the bulk of California orchard cover crop research being in that crop). Daniele Zaccaria has been...

When to Start Irrigating Walnuts

20 Mar 2024

Contributed by Lukas

Luke Milliron and Ken Shackel (UC Davis) sit down to talk about the decade plus of research investigating when to start irrigation in the spring for w...

Carpophilus truncatus with Houston Wilson

13 Mar 2024

Contributed by Lukas

In a world where it feels like we have a new invasive pest every month, sometimes it’s hard for an arthropod to stand out. Last year, the nut indust...

Encore: Pecan Basics with Dr. Richard Heerema

05 Mar 2024

Contributed by Lukas

Phoebe talks with Richard Heerema, the pecan specialist for New Mexico State University, about pecan botany and physiology, and why it may not be as g...

Florent Trouillas on the use of Orondis in pistachios

27 Feb 2024

Contributed by Lukas

Florent Trouillas, a professor of Cooperative Extension in plant pathology at UC Davis, describes how pistachios become infected with phytophthora and...

New UC Davis Prune Varieties Prove Promising

21 Feb 2024

Contributed by Lukas

Sarah Castro (UC Davis) discusses how new prune varieties can improve a grower’s bottom line!scastro @ ucdavis.eduInsta: @cali.prunebreederInitial e...

2024 water outlook with Sam Sandovol Solis

06 Feb 2024

Contributed by Lukas

Phoebe and Sam discuss the water outlook for 2024. Some things have changed since last year, but some things have stayed the same. Listen to the entir...

Encore: Pistachio Dormancy with Craig Kallsen

30 Jan 2024

Contributed by Lukas

While we posted this episode all the way back in 2018, we thought we would dust it off since the information is still timely.Phoebe interviews Craig K...

2024 Bee Outlook with Brittney Goodrich

23 Jan 2024

Contributed by Lukas

Brittney Goodrich provides an update on what almond growers can expect in the 2024 pollination season. You can find the economic calculator here.Come ...

The War Against Navel Orangeworm in 2023-2024

09 Jan 2024

Contributed by Lukas

Navel Orangeworm (NOW) wreaked devastating impacts on the California almond industry in 2023. I sat down with Dr. Franz Niederholzer (UCCE Colusa) aft...

Nematode Management in Walnut: 2023

27 Sep 2023

Contributed by Lukas

Dr. Andreas Westphal provides an update on tightening regulations and the latest research progress for nematode management in walnuts and other orchar...

Encore: Almond Harvest Timing with Mel Machado

01 Sep 2023

Contributed by Lukas

Mel Machado (Blue Diamond Almond Growers) discusses important considerations for timing almond harvest, including grower objectives, varieties, and nu...

Evapotranspiration of pistachios in saline conditions with Daniele Zaccaria

08 Aug 2023

Contributed by Lukas

Pistachios are very salt tolerant, at least compared to most of the other orchard crops that are grown in California. However, this does not make them...

Encore: Postharvest Weed Survey & Management with Drew Wolter

26 Jul 2023

Contributed by Lukas

Drew Wolter (now former UCCE farm advisor intern) and Luke Milliron discus why the postharvest weed survey helps form the backbone of an integrated we...

Whole orchard recycling: application, fertilization, and diseases with Brent Holtz

12 Jul 2023

Contributed by Lukas

Whole orchard recycling is thepractice of incorporating recycled wood chips from oldorchards into soil priorto planting a new orchard. While this can ...

Navel Orangeworm mating disruption neighbors program

28 Jun 2023

Contributed by Lukas

Mating disruption has been found to reduce NOW damage in almonds by, on average, 50%, however we think it is most effective when it is applied in bloc...

Pacific flatheaded borer update with Jhalendra Rijal

13 Jun 2023

Contributed by Lukas

Pacific flatheaded borer has recently become a pest of concern in walnuts, though it has been known to damage walnuts for a long time. Jhalendra Rijal...

Ganoderma adspersum update with Daisy Hernandez

10 May 2023

Contributed by Lukas

Daisy Hernandez has been conducting research on Ganoderma adspersum as part of her doctoral dissertation. She shares some more things that she’s lea...

Whole orchard recycling in walnuts with Luke Milliron

25 Apr 2023

Contributed by Lukas

Whole orchard recycling (WOR) is becoming commonplace in almonds, and we have several research trials scattered across the state examining best practi...

Phosphorus fertilization in newly planted almonds with Phoebe Gordon

11 Apr 2023

Contributed by Lukas

Phoebe discusses some research she has conducted with Greg Browne (USDA plant pathologist) on examining phosphorus fertilization in newly planted almo...

Testing Treatments for Low Winter Chill in Walnut

16 Mar 2023

Contributed by Lukas

Dr. Katherine Jarvis-Shean (UCCE Yolo, Solano, and Sacramento) and Luke talk about the early testing of treatments for low winter chill in California ...

Sacramento Valley March Orchard Tasks in 2023

06 Mar 2023

Contributed by Lukas

Franz Niederholzer (UCCE Colusa and Sutter-Yuba) and Luke talk about March almond, prune, and walnut tasks in the Sacramento Valley.  Sac Valley ...

2023 water outlook with Sam Sandovol Solis

14 Feb 2023

Contributed by Lukas

In this episode, Phoebe talks with Sam Sandovol Solis, a professor of water management at UC Davis, about the 2023 water outlook. It’s looking a lot...

2023 Bee outlook with Brittney Goodrich

03 Feb 2023

Contributed by Lukas

Phoebe discusses the 2023 bee outlook with Brittney Goodrich, an agriculturlal economics Professor of Cooperative Extension at UC Davis. Like in prev...

2022 Orchard IPM Retrospective

10 Jan 2023

Contributed by Lukas

IPM Advisors David Haviland, Dr. Jhalendra Rijal, and Dr. Sudan Gyawaly look back on the 2022 almond, walnut, and pistachio highlights from the south,...

Leaffooted Bug Lure update with Houston Wilson

13 Dec 2022

Contributed by Lukas

Leaffooted bugs are a sporadic pest in orchards, but when they appear they can cause serious damage. There are few management guidelines as it is bel...

Compost May Not Improve Orchard Performance with Roger Duncan

06 Dec 2022

Contributed by Lukas

Roger Duncan discusses his research over several years showing that in some situations compost may not improve orchard performance and grower bottom l...

Encore: Leslie Holland on Botryosphaeria in Almonds

23 Nov 2022

Contributed by Lukas

Leslie Holland, Assistant Professor at University of Wisconsin, Madison, shares the results of some of her work examining fungicides to suppress Botry...

Bacterial canker with Mohammad Yaghmour

17 Nov 2022

Contributed by Lukas

Bacterial canker can be a serious disease affecting young Prunus species. It is closely connected to weather and tree health. Mohammad Yaghmour discus...

November 2022 1MC

07 Nov 2022

Contributed by Lukas

Call or text 530-487-5991 to ask questions for Phoebe and Luke to answer or provide feedback about adapting the 1 Minute Challenge Upcoming Field...

Walnut Freeze with Luke Milliron

26 Oct 2022

Contributed by Lukas

Luke discusses the recent history of sudden autumn walnut frost events in California’s Central Valley, how to prevent damage ahead of the next sudde...

Encore: Irrigation Part 4. Soil Moisture Monitoring with Allan Fulton

19 Oct 2022

Contributed by Lukas

Measuring soil moisture by hand with the “feel” method, or with modern senor technology can be a powerful irrigation management tool. I sit down w...

Cover crops on NOW mortality with Kadie Britt

11 Oct 2022

Contributed by Lukas

Kadie Britt discusses research results from a project examining the effects of cover crop on overwintering NOW larvae mortality. Upcoming meetings: In...

October 2022 1MC

04 Oct 2022

Contributed by Lukas

It’s October, the year is almost over! Phoebe and Luke compete to see who can go over the month’s tasks, using whatever metric they feel is the be...

Heat Mitigation with Ben Faber

28 Sep 2022

Contributed by Lukas

Dr. Ben Faber (UCCE Ventura County) discusses the effects of heat damage in orchard crops and practices to help manage high temperatures that are occu...

Encore: Managing Mold in Walnut with Themis Michailides

20 Sep 2022

Contributed by Lukas

Dr. Themis Michailides has been seeing increased mold in walnut pathology samples in recent years. The UC Davis Plant Pathologist at the Kearney Ag Ce...

2022 SIT for NOW Update with Houston Wilson

13 Sep 2022

Contributed by Lukas

Houston Wilson (Entomology Specialist with UC Riverside) gives Phoebe an update on a project examining whether sterile NOW moths can be an effective a...

September 2022 1MC

06 Sep 2022

Contributed by Lukas

Phoebe and Luke discuss important tasks for September, orchard observations, and other thoughts.Upcoming webinar: “Practical Canker Management in Al...

Mechanical Hedging of Prunes with Rich Rosecrance and Becky Wheeler-Dykes

31 Aug 2022

Contributed by Lukas

Dr. Rich Rosecrance and Becky Wheeler-Dykes (CSU Chico) discuss their latest findings on the mechanical pruning of prune trees. You can learn more at:...

Encore: Cytospora in Prune with Themis Michailides

23 Aug 2022

Contributed by Lukas

In this encore episode Dr. Themis Michailides (UC Davis Plant Pathologist) discusses his lab’s advances against Cytospora cankers, a disease that ca...

Encore: Irrigation Part 9: Irrigation Pumps with Jon Chilcote

19 Aug 2022

Contributed by Lukas

Phoebe discusses irrigation pumps, including their capacity and maintenance, with Jon Chilcote, a USDA NRCS team engineer for the Southern San Joaquin...

Black Fig Fly with Kadie Britt

16 Aug 2022

Contributed by Lukas

Despite it’s fun acronym (BFF), the newly introduced Black Fig Fly is no friend to figs. Native to the Mediterranean, it’s recently been found in...

August 2022 1 Minute Challenge

04 Aug 2022

Contributed by Lukas

Phoebe and Luke talk about best management practices in almonds, pisachios, walnuts, and prunes, as well as the problems they’re diagnosing out in t...

Almond Harvest Timing with Mel Machado

26 Jul 2022

Contributed by Lukas

Mel Machado (Blue Diamond Almond Growers) discusses important considerations for timing almond harvest, including grower objectives, varieties, and nu...

Irrigation in Prune with Franz Niederholzer

20 Jul 2022

Contributed by Lukas

Dr. Franz Niederholzer (UCCE Orchard Advisor in Colusa and Sutter/Yuba) discusses how irrigation best practices in prune orchards this summer maximize...

July 2022 1 Minute Challenge

11 Jul 2022

Contributed by Lukas

Phoebe and Luke discuss important things to keep track of in July.Thank you to the Almond, Pistachio, Prune, and Walnut Boards of California for their...

Drought in Almond with Ken Shackel

30 Jun 2022

Contributed by Lukas

Dr. Ken Shackel (UC Davis) sits down to discuss what we know about coping with drought in almond production. For more information consult the UC Almon...

Breeding Pt. 5: Prune with Sarah Castro

24 Jun 2022

Contributed by Lukas

In the 200th episode of Growing the Valley Podcast – Sarah Castro (UC Davis) discusses exciting new varieties in the prune breeding program. Mark yo...

Encore: Field Evaluation of Almond Varieties - Results Through 7th Leaf

14 Jun 2022

Contributed by Lukas

Phoebe, Luke, and Roger Duncan (UCCE Stanislaus) discuss results out of their respective regional almond variety trial sites. Additional resources: Tw...

Spotted Lanternfly with Surendra Dara

09 Jun 2022

Contributed by Lukas

Spotted Lanternfly is in the United States and could pose a threat to some of the specialty crops we grow here in California. Surendra Dara explains ...

Whole Orchard Recycling Update with Mae Culumber and Brent Holtz

01 Jun 2022

Contributed by Lukas

Dr. Mae Culumber (Fresno County) and Dr. Brent Holtz (San Joaquin County) discuss how Whole Orchard Recycling—the practice of incorporating recycled...

June 2022 1MC

01 Jun 2022

Contributed by Lukas

Phoebe and Luke step up to the plate once again to see who wins this month’s one minute challenge! They also discuss farm call trends and other iss...

Encore: Irrigation Part 2: Basic Irrigation Technologies With Spencer Cooper

18 May 2022

Contributed by Lukas

In today’s episode, Phoebe talks with Spencer Cooper of the Almond Board of California on how to go from running water through your orchard to preci...

ETa with Mallika Nocco

10 May 2022

Contributed by Lukas

Mallika Nocco (Specialist at UC Davis) discusses ETa with Phoebe, as well as some research she is doing to try to develop a method for managing irriga...

Walnut Dormancy with Katherine Jarvis-Shean

03 May 2022

Contributed by Lukas

Climate change is a threat to high chill crops like walnuts, and we know very little about how these plants will react (they’re too big to do contro...