Growing the Valley

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 Central Valley to some orchards in the northern Sacramento Valley with only half leaf out. This disorder also called leafing failure, severely affected many growers in the northern Sacramento Valley. Dr. Tom Gradziel (UC Davis) gets into the complexities...

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 we’re likely to see it on future almond varieties, not just on Carmel? Tom Gradziel discusses the science behind NBF and the work UC researchers together with nurseries have done to make massive gains in addressing the problem. You can lead more abo...

Regenerative agriculture is currently all the rage these days in some circles. With a broad range of practices that can be classified as regenerative, it still can feel like a mushy term that means different things to different people (which is actually by design). Amelie Gaudin sits down with Phoebe Gordon to discuss what qualifies as a regenerative practice, how the focus differs from “conventio...

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 entry into walnut wood, or by weaking branches, making them more vulnerable to infection. In this episode In this episode, Elizabeth Fichtner discusses the lifecycle of the pest and control options. Note: while walnut scale does appear in almonds, th...

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 about summer fruit growth, key financial considerations at harvest, and finishing the season strong in the postharvest period. Luke Milliron assembled an expert panel of UCCE Farm Advisors, Franz Niederholzer (UCCE Colusa), Jaime Ott (UCCE Tehama),...

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 Wheeler-Dykes (UCCE Glenn) and host Luke Milliron (UCCE Butte) talk about the formation of fruit buds all the way through to fruit thinning in spring. Topics include weather at bloom , the importance of weather the 30 days after bloom , and a calculator...

. Oak root fungus (Armillaria root rot) is a devastating disease that can plague orchards generation after generation. Resistant rootstocks is the answer. Roger Duncan (UCCE Advisor Emeritus) discusses early findings in his ORF rootstock trial. Mention of a pesticide does not constitute a pesticide recommendation, merely the sharing of research results. Consult your PCA and read the pesticide labe...

Phytophthora isn’t just an early season problem anymore. On this episode of the podcast, Dr. Jim Adaskveg (UC Riverside) talks warm season phytophthora management in almond. You can round out your phytophthora expertise by listening to earlier episodes with Dr. Greg Browne (USDA) covering Phytophthora in almond and walnut orchards , as well as an episode with Dr. Florent Trouillas on aerial phytop...

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 pistachios are sold in-shell. Have you ever wondered how those shells split? In this episode, Phoebe sits down with Shuxiao (Susan) Zhang and Georgia Drakakaki, two of the authors of a recently published study on the mechanisms behind pistachio shell splitti...

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 management of this perennial weed in orchards. UC ANR has great resources on distinguishing Johnsongrass and other young summer grass weeds . Johnsongrass identification photos can also be found on the podcast website . ANR also has a great guide to Joh...

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 to trial these new clones, in particular K3 an exciting new rootstock that has produced good growth, yield, and very low crown gall. You can contact Pat at pjbrown@ucdavis.edu . Please also CC your local UCCE walnut farm advisor . Come to an upcoming...

Three PhD entomologists with UC Cooperative Extension: Sudan Gyawaly, Jhalendra Rijal, and Houston Wilson discuss integrated management of the leaffooted and stink bug pest complexes in California nut crops. Be sure to first listen to part I where the three experts discuss phenology and monitoring of these pest complexes. More information on controlling plant bugs in almonds and pistachios can be...

Three PhD entomologists with UC Cooperative Extension: Sudan Gyawaly, Jhalendra Rijal, and Houston Wilson discuss the phenology and monitoring of the leaffooted and stink bug pest complexes in California nut crops. Including an exciting update from Houston Wilson (UC Riverside) on the trap and lure for leaffooted bug. Stay tuned for part two where the expert panel discusses the integrated manageme...

Dr. Roger Baldwin (UCCE Specialist in Human-Wildlife Conflict Resolution) discusses orchard management of pocket gophers, ground squirrels, voles (meadow mice), roof rats, and deer mice. This is a compilation of two episodes from 2022, with Luke Milliron providing a new introduction with highlights from 2024/2025. Skip to the pest you’re concerned about: 00:05:35 Pocket Gophers 00:35:12 Ground Squ...

Drs. Or Sperling (ARO-Volcani) and Maciej Zwieniecki (UC Davis) discuss their groundbreaking research on almond irrigation. That research has culminated in an exciting irrigation scheduling application . We also get an overview of almond production in Israel. The UC Davis Carbohydrate Observatory is also referenced. Come to an upcoming extension meeting! Sacramento Valley San Joaquin Valley (scrol...

Cytospora is a devastating fungal canker disease in California prune production. Themis Michailides (UC Davis at Kearney Ag Center) updates us on the biology and management of this important disease. Themis has covered this disease on the podcast before but is back with key updates. Come to an upcoming extension meeting! Sacramento Valley San Joaquin Valley (scroll to the bottom) The views, though...

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 cause health issues to animals - it impacts plants, too! Jessica Orozco and Maciej Zwieniecki at UC Davis have been using citizen science data from The Carbohydrate Observatory to try to guess at the impacts on tree nut orchards in the Central Valley....

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 accumulation. Katherine Jarvis-Shean (UCCE Yolo, Solano, and Sacramento Counties) has been looking at the efficacy of rest-breaking agents, both in semi-controlled conditions and in commercial orchards. She shares how well they work, their effect on...

Nonstructural carbohydrates are the energy storage compound of trees. They are built from simpler sugars that are created via photosynthesis, and the synthesis of starch from these sugars and the breakdown of starch back into simple sugars is a dynamic relationship that is involved in, or may even signal, the transition from dormancy into bloom. Guests Maciej Zwieniecki and Katherine Jarvis-Shean...

Almonds and pistachios are native to arid climates and are drought tolerant tree species. In California however, the high cost of production and land value pushes growers to maximize yields, which means trying to meet the full evaporative demand (though many growers apply much less water than this!) This is not the strategy everywhere, however, even in other areas that also have high production co...

At a time when California orchard farmers are being challenged by poor economics and tightening regulations – coming irrigation advances promise labor and time savings. I speak with Tom Devol (retired Almond Board of California) to discuss the past, present, and future of California orchard irrigation.  Come to an upcoming extension meeting! Sacramento Valley San Joaquin Valley (scroll to the...

Phellinus heart rot in prune trees destroys structural integrity. Laurel Hoffman (UC Davis) updates us on the biology and management of this important disease. Come to an upcoming extension meeting! Sacramento Valley San Joaquin Valley (scroll to the bottom) The views, thoughts, and opinions expressed are the speaker’s own and do not represent the views, thoughts, and opinions of the University of...

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 wildfire events that are unfortunately too common. Episode transcription Come to an upcoming extension meeting! Sacramento Valley San Joaquin Valley (scroll to the bottom) The views, thoughts, and opinions expressed are the speaker’s own and do not repr...

Sudden autumn freeze events still sneak up on California walnut growers – as they did to some growers last Halloween (2023). Clarissa Reyes (UCCE Sutter-Yuba) and Luke Milliron (UCCE Butte) discuss the steps to prepare for freeze in walnut. At the time of posting – there was patchy frost on the morning of 11/18/24 and predicted also for 11/19/24. Thankfully, there is surface soil moisture in orcha...

It’s been a year since Carpophilus truncatus (Carpophilus beetle) was found in California. Jhalendra shares some research updates and observations with host Phoebe Gordon. Come to an upcoming extension meeting! Sacramento Valley San Joaquin Valley (scroll to the bottom) Mention of an agrichemical does not constitute a recommendation, merely the sharing of research findings. Always follow the label...