Growing the Valley

Luke Milliron, Phoebe Gordon, and Roger Duncan discuss the three almond variety trials 10 years after they were planted across the Central Valley. Thanks to our grower cooperators and to the Almond Board of California for funding these trials. You can find more about the results discussed in our 2023 report . Details discussed can also be found in an upcoming fall/winter issue of West Coast Nut. &...

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 newer cultivars, Golden Hills and Lost Hills, alternate bear less than Kerman, especially when they are planted on the high vigor UCBI. Doug Amaral (UCCE Kings County) decided it was time for an update on the nitrogen demand curves, and we discuss wha...

A Third Thursday x Growing the Valley collab! Karla Caldera (CSUC graduate student) discusses the research she is conducting at the walnut variety trial located at the Chico State University Farm (2:27) and Dr. Pat J. Brown talks and answers grower questions about the Walnut Improvement Program at UC Davis that aims to bring improved plant material to the walnut industry (9:50). Check SVO for futu...

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. The methods for calculating chill has changed, but the measurement method, measuring air temperatures, has not. Giulia Marino, Professor of Cooperative Extension at UC Davis, measured the bark temperature of cherry trees in a recent research project....

Phoebe breaks down the importance and best practices surrounding potassium nutrition in orchard crops. Phoebe and Franz Niederholzer wrote an excellent article on K nutrition CDFA – FREP Fertilization Guidelines Sign up for the 2024 Pistachio Short Course here : Thank you to the Almond, Pistachio, Prune, and Walnut Boards of California for their kind donations. Thank you to Muriel Gordon for the m...

Measuring plant water status is a critical but underused tool in irrigation management. It allows us to determine whether plants actually need water, but is time consuming, done during the hottest portion of the day, and difficult to do at a large scale. Commercial devices to measure plant water status are a fairly recent addition to the agricultural tech field, but are they accurate? Isaya Kisekk...

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 for symptoms of Tomato ringspot virus in almond, peach, and cherry. Also caused by Tomato ringspot virus: Learn about Yellow Bud Mosaic in almond and peaches Learn about Cherry Stem Pitting     Come to an upcoming extension meeting! Sacramen...

Houston Wilson, Professor of Cooperative Extension in entomology with UC Riverside, gives us our semi-yearly update on Sterile Insect Technique (SIT) work in Navel Orangeworm, through work completed in 2024. It’s a long (20 year or so) long road, but may provide an additional tool in the IPM toolbox for controlling navel orangeworm. Listen to find out more! Come to an upcoming extension meeting! S...

Incorporating large amounts of woody biomass into soil, such as in whole orchard recycling (WOR), can promote carbon sequestration, nutrient recycling, and ecosystem health in agricultural fields. Yet uncertainty regarding the effects of WOR on soil carbon and nitrogen dynamics influences management decisions. Recently, Mae Culumber, Ph. D. with UC Cooperative Extension, Suduan Gao, Ph. D. with th...

Soil health is broad term that encompasses a important topic: functional soil that can support human activities, animals, and plants. Measuring soil health can be difficult even for soil scientists, but in today’s episode, Sarah Light shares some tools that growers, PCAs, and CCAs can use to judge soil health in their or their clients’ orchards. The slakes app The Soil Health Connection YouTube ch...

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 phytophthora. Florent Trouillas with UC Davis goes over the pathogen, its lifecycle, and the conditions in 2023 that led to this outbreak. Podcast transcript Come to an upcoming extension meeting! Sacramento Valley San Joaquin Valley (scroll to the bottom)...

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

This week, we share an episode that was TWO YEARS IN THE MAKING (if you count continually rescheduling episode recording sessions due to various conflicts and then forgetting about it for a year as making an episode). Phoebe interviews Amisha Poret-Peterson with the USDA-ARS on the basics of soil microbiology. We discuss the complexity and role of the soil microbiome, bulk soil vs the rhizosphere,...

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!). Please note that there are other physiological causes of blanking, such as incomplete pollination or aborted kernel development, and that we have not determined how much dust could contribute to blanking in the field. Also, the episode was recorded bef...

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 conducting research on cover crops in California pistachio orchards and shares what he has found, including some interesting possibilities as to why they found higher yields in orchards with cover crops. Episode transcript Come to an upcoming extensio...

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 walnut orchards. If you want to learn more about incorporating the pressure chamber to improve orchard health and cut costs - contact your local farm advisor or Luke at (530) 828-9666 Come to an upcoming extension meeting! Sacramento Valley San Joaqui...

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 industries were put on notice by Carpophilus truncatus, a tiny beetle that has commandeered big attention. Lucky for us (and unluckily for the Australians), we aren’t alone in trying to figure out how to keep this beetle under control. Houston Wilson shares...

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 good of a choice for areas prone to flooding as you think it might be. This is an episode for those who are thinking of planting pecans but have not done so. Podcast transcript Come to an upcomi ng extension meeting! Sacramento Valley San Joaquin Vall...

Florent Trouillas, a professor of Cooperative Extension in plant pathology at UC Davis, describes how pistachios become infected with phytophthora and how to manage it. He also describes his research on this newly registered product. Episode transcript Come to an upcoming extension meeting! Sacramento Valley San Joaquin Valley (scroll to the bottom) Mention of an agrichemical does not constitute a...

Sarah Castro (UC Davis) discusses how new prune varieties can improve a grower’s bottom line! scastro @ ucdavis.edu Insta: @cali.prunebreeder Initial episode on the prune breeding program with Sarah 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, thou...

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 Kallsen, the now emeritus subtropical and pistachio tree crop advisor for Kern County, to talk about what we know and don’t know about dormancy in pistachios. Craig also talks about a paper he published back in 2017, looking at the correlation betwee...

Navel Orangeworm (NOW) wreaked devastating impacts on the California almond industry in 2023. I sat down with Dr. Franz Niederholzer (UCCE Colusa) after harvest to discuss what had happened and what needs to be done to win the war against NOW in 2024. Come to an upcoming extension meeting! Sacramento Valley San Joaquin Valley (scroll to the bottom) Mention of an agrichemical does not constitute a...

Dr. Andreas Westphal provides an update on tightening regulations and the latest research progress for nematode management in walnuts and other orchard crops. Dr. Westphal’s upcoming nematode management field days will be on Tuesday November 28 (walnut), and Wednesday November 29 (almond) at the Kearney Ag Center (9240 S. Riverbend Ave, Parlier, CA). Who is it for? Field research representatives,...

Mel Machado (Blue Diamond Almond Growers) discusses important considerations for timing almond harvest, including grower objectives, varieties, and nut quality. Resource links related to almond harvest: When do you shake almonds? Maintaining Quality with Pick Up & Stockpiling Best Practices Thank you to the Almond, Pistachio, Prune, and Walnut Boards of California for their kind donations. Tha...

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 immune to the effects of salinity. Daniele Zaccaria recently wrapped up a four year study examining the water use of trees under varying levels of soil salinity and found that water use decreases as soil salinity increases. This has major implicatio...