California Fruit and Vegetable

Tag: UC Cooperative Extension

  • UC Seeks Consumers to Weigh in on New Method of Controlling Asian Citrus Psyllids

    To understand consumers’ attitudes toward a bioengineered pesticide for citrus crops, University of California Agriculture and Natural Resources researchers are asking for volunteers to participate in focus groups in Riverside, Oakland and Fresno.

    Bacillus thuringiensis, or Bt, is a naturally occurring bacterium being tested to control the spread of Asian citrus psyllid, the small insect that transmits the disease huanglongbing to citrus trees. Both the Asian citrus psyllid and huanglongbing have been found in Southern California backyard citrus trees and threaten to spread throughout the state.

    Huanglongbing, also known as citrus greening disease, is a bacterial infection that stunts citrus trees, reduces their fruit production, deforms and greens the fruit and eventually kills the tree. There is no known cure or effective control.

    The disease has already devastated Florida’s citrus industry, slashing the state’s orange production by 92% between 2005 and 2025, according to Karen Jetter, associate director and project economist at the UC ANR Policy Institute. By the time the magnitude of the problem was revealed, both Asian citrus psyllid, or ACP, and huanglongbing were widespread in Florida.

    “In California, we still have the opportunity to slow the spread of huanglongbing through ACP management,” Jetter said.  “This unique technology is designed to be part of a comprehensive ACP management program, not to replace it.”

    Jetter and Fiona Ogunkoya, survey researcher at the UC ANR Policy Institute, are conducting focus groups to assess consumer attitudes toward an engineered Bt pest control method that targets Asian citrus psyllids, the primary vector of the disease, to stop the spread of huanglongbing.

    The bioengineered pest control strategy, developed in Florida and shown to be effective, uses an engineered citrus tristeza virus to transmit an engineered Bacillus thuringiensis to citrus trees. The Asian citrus psyllid lays eggs on the tender new leaf growth of the trees. After the nymphs hatch, the immature insects consume the modified Bt-infected leaves, become sick and die.

    California citrus growers surveyed by Sandipa Gautam, UC Cooperative Extension integrated pest management citrus advisor, said they are interested in the approach. But they growers are concerned that consumers will not accept fruit grown with this new bioengineered insecticide.

    To find out what consumers think, the researchers will meet with three focus groups, with each session limited to six to eight people to allow all participants time to express their thoughts.

    The 90-minute focus group meetings will be held at UC Cooperative Extension offices in Riverside on March 30 at 6 p.m., in Oakland on April 6 at 2 p.m. and in Fresno on April 8 at 2 p.m. Pizza will be served.

    To participate in a focus group, register for a session at https://forms.gle/QPyUd7QazTLfNdATA. To be eligible, participants must be 18 years of age or older and able to attend the focus group in person. — By UC Agriculture and Natural Resources

  • Groundwater Markets Tested in Mojave Basin

    As growers navigate SGMA, different avenues are being explored for access to the needed water for crops, including groundwater markets. This has been experimented with in the Mojave Basin, resulting in stabilized implementation  and aggregate gains, but also a consolidation of water rights. At the World Ag Expo, UC Cooperative Extension Associate Professor Ellen Bruno discussed the findings on groundwater markets with Matthew Malcolm at California Ag Network. Watch this quick video and read more in California Fruit & Vegetable Magazine.

    Please thank this video’s sponsor Simplot for their industry support.

  • Didn’t Get Much of a Cherry Crop This Year? This Might be Why…

    Some Central Valley cherry growers grappled with little to no yields this year. Cherries are notoriously a high risk crop, but can be highly profitable when they yield well. Unfortunately, that was not the case for some Central Valley growers this year. But how could this have happened? UC Cooperative Extension Fruit & Almond Advisor Raymond Mireles met with Matthew Malcolm on California Ag Network to explain. Watch this brief interview and read more about it in the coming issue of California Fruit & Vegetable Magazine.

    Please thank this video’s sponsor Simplot Grower Solutions for their industry support.

  • Five Ways to Avoid Expensive Irrigation Repairs & DU Losses

    Irrigation systems today are amazing at getting just the right amount of water where it needs to be to meet a crop’s needs; however, if these systems are not well-maintained, things can go south pretty fast, resulting in distribution uniformity-related losses and expensive repairs. During his presentation at Malcolm Media’s recent Tree & Vine Expo, UC Cooperative Extension Irrigation & Soils Advisor Moneim Mohamed noted that regular and proper irrigation system maintenance can prevent expensive repairs.  Watch his video interview with Matthew Malcolm on California Ag Network for five key tasks for preventative maintenance.

    Please thank this video’s sponsor Simplot Grower Solutions for their industry support.

  • Stink Bugs Foul Up Central Valley Stone Fruit

    While growers hoped the invasive brown marmorated stink bug would stay out of California orchards, they seem to have taken a liking to stone fruit, along with other stink bug species, and caused problems for some growers this year. UC Cooperative Extension Fruit & Almond Advisor Raymond Mireles shared this at Malcolm Media’s recent Grape, Nut & Tree Fruit Expo in Fresno. Following his presentation, Raymond met with Matthew Malcolm on California Ag Network to explain. Watch this brief interview and read more about it in California Fruit & Vegetable Magazine.

    Please thank this video’s sponsor Simplot Grower Solutions for their industry support.

  • Why Do Some of My Peaches Stay Small and Never Fully Develop?

    Have you seen “nubbins” in your orchard? During a presentation at Malcolm Media’s recent Tree & Vine Expo, UC Cooperative Extension Farm Advisor Cameron Zuber described nubbins as occasional smaller sized fruit you may find on a peach tree that never fully develops. Watch this brief interview as Zuber meets with Matthew Malcolm on California Ag Network to explain nubbins and why you might be seeing them in your orchard.

    Please thank this video’s sponsor Simplot Grower Solutions for their industry support.

  • AI Tool to Help Farmers Measure Real-Time Crop Health from the Field

    Leaf Monitor, a new mobile tool backed by artificial intelligence and predictive modeling, could revolutionize how farmers monitor crops and make decisions by providing real-time nutrition and leaf trait information in the field.

    “Having this information is very valuable for the farmers,” said Alireza Pourreza, associate professor of Cooperative Extension and director of the Digital Agriculture Laboratory in the Department of Biological and Agricultural Engineering at the University of California, Davis. “In five seconds, they can have a sense of how much nutrition they have in a leaf.”

    Development of the AI model was funded by the U.S. Department of Agriculture’s National Institute of Food and Agriculture’s HiRes Vineyard Nutrition multistate project and its Animal and Plant Health Inspection Service, as well as the California Table Grape Commission.

    Maha Afifi, director of viticulture research at the California Table Grape Commission, said the tool could be a game changer for the table grape industry if it leads to faster decision-making about fertilizer use. The right amount typically leads to healthier vines that produce more grapes with optimal size, weight and color.

    “The evaluation of vine nutrient status is one of our top priorities,” Afifi said. “At the same time, exploring new technology tools like this project is a high priority for us because they will be important to the future of the table grape industry.”

    Field testing

    The Leaf Monitor tool uses a handheld spectrometer to measure leaf reflectance beyond the range of light visible to the human eye.

    Once a leaf is scanned, its spectral data is uploaded to a cloud-based machine learning system designed to predict leaf traits and nutrient content. This algorithm was developed and trained by the Digital Agriculture Laboratory over five years using a dataset of thousands of leaf samples collected from California’s specialty crops, primarily grapevines and almonds. The samples were chemically analyzed to determine nutrient levels and structural leaf traits, providing the data needed to build an accurate prediction model.

    “Nutrient deficiencies in plants often go unnoticed until late in the season, by which point the damage is already irreversible,” said graduate student Parastoo Farajpoor, who is running the project. “This is why early detection is essential. Spectrometry provides a rapid and reliable way to identify these deficiencies before visible symptoms appear.”

    After a recent demonstration, Bulleseye Farms Irrigation Manager Geoff Klein said the tool could help save money and improve yields. Bullseye grows walnuts, pistachios, tomatoes, corn, wheat, rice and sunflowers in Yolo and Solano counties.

    Tailored crop management

    Currently, farmers typically take leaf samples, dry them, grind them up and send the samples off to a lab for testing, which can take up to two weeks to return results. Bullseye samples leaf tissues about three times a year.

    “Right now, it doesn’t really make sense to go out and take tissues in every single corner just because it’s expensive,” Klein said. “It’d be really cool if I could just walk out there and test a couple of different places.”

    The Leaf Monitor tool helps farmers tailor management decisions to specific areas rather than an entire field. Calibrating fertilizer use to real-time data can prevent overuse and nitrogen runoff, a financial and environmental challenge that many growers face.

    “I feel like there’s a lot of times we do need to put less [fertilizer] on, where we end up putting more, because that’s what the nitrogen removal formula says,” Klein said. “But with this app we can use less because we know the actual conditions at the time. I think it opens a lot of doors in terms of getting data back in real time and also utilizing the level of control we have with the data.”

    The app can also aggregate the scans and map out spatial patterns over a large area.

    “What we know is every field has variability that is not necessarily visible to the farmer’s eye,” Pourreza said.

    The prototype Leaf Monitor tool is free and included in a set of tools that can be downloaded on the Digital Agriculture Laboratory website. A web-based version of the tool will follow while the team continues to feed new data into the algorithm to refine the predictions. On average, it achieves about 65% accuracy across all traits, with predictions for certain nutrients, such as nitrogen and phosphorus, performing better than the overall average. Users will need to pair it with a spectrometer.

    “We need to produce more food while using less resources so we need to have some kind of monitoring system to give us precise and accurate feedback on our management practice,” Pourreza said. “This technology is growing very fast.” — By Emily Dooley, UC Davis

  • How to Effectively Control Rats on California Farms in a State of Emergency

    Rats have taken an unusual interest in the specialty crop capital of the nation. Many attribute the cause to the pest multiplying unchecked in orchards and vineyards in the Central Valley that have been abandoned due to water restrictions and economic challenges. This becomes a real problem when the rats move into neighboring farms in active production, tearing up driplines, feeding on crops and damaging trees. Growers are in a state of emergency and have limited tools for managing this pest.  Malcolm Media Editor-in-Chief Matthew Malcolm met with UCCE Wildlife Specialist Roger Baldwin at the California Association of Pest Control Adviser’s annual conference to gain answers on how to knock down populations effectively and keep the pest at bay.  Watch this brief interview and learn more by attending Baldwin’s presentation on rat control at the Grape, Nut & Tree Fruit Expo at the Fresno Fairgrounds on Nov. 14 (register to attend at agexpo.biz).

    Please thank this video’s sponsor Simplot Grower Solutions for their industry support.

  • UC Releases Costs of Growing Cilantro, Parsley

    For commercial growers considering planting cilantro or parsley, the costs and returns of producing in Ventura County are outlined in a new study by the University of California Cooperative Extension, University of California Agriculture and Natural Resources Policy Institute, and UC Davis Department of Agriculture and Resource Economics.

    “These studies provide growers with a baseline to estimate their own costs, which can help if they need to apply for production loans, project labor costs or market their crop” said Etaferahu Takele, UC Cooperative Extension farm management advisor and agricultural economist and study co-author.

    The UC Cooperative Extension cost and return estimates are based on cilantro and parsley grown in Ventura County. Each study describes the cultural practices used for establishing, producing and harvesting the herbs, including land preparation, soil fertility and pest management, irrigation and labor needs.   

    Ventura County produces a diverse mix of vegetables and herb crops. Lately, the acreage in cilantro production has been increasing. Between 2002 and 2022, the cilantro acreage almost quadrupled from 1,257 acres to 4,065 acres, reflecting increases in demand for the herb often used in Latin American and Asian recipes.

    The total cost to produce cilantro in 2025, using a yield of 1,200 cartons per acre, is approximately $7,316 per acre. Sold for $9 per carton, profit for cilantro before paying management is estimated at $3,480 per acre.

    The total cost to produce parsley in 2025, using a yield of 2,200 cartons per acre, is approximately $14,759 per acre. Using a price received of $8.60 per carton, profit for parsley before paying management, is estimated at $4,713 per acre.

    The researchers based their studies on an 800-acre farm, which was the average farm size of the growers they interviewed. Double cropping is common in Ventura County so the total land farmed for this sample is about 1,600 acres per year. Because growers produce multiple crops each year, planting and harvesting vegetable crops are year-round activities.

    “Cilantro Production Costs and Profitability Analysis” and “Parsley Production Costs and Profitability Analysis” can be downloaded for free from the UC Cooperative Extension Ventura County website: https://ucanr.edu/county/cooperative-extension-ventura-county/vegetable.

    Government agencies such as the California Department of Food and Agriculture and the United States Department of Agriculture can use the information when developing and implementing agricultural policies and programs.

    The cost estimate studies were coauthored by Oleg Daugovish, UC Cooperative Extension strawberry and vegetable crop advisor in Ventura County; and Karen Jetter, research economist and associate director; Donald Stewart, staff research associate; and Fiona Ogunkoya, survey researcher, all of the UC ANR Policy Institute.

    For more information about cost studies, contact Takele at ettakele@ucanr.edu.

    These studies were funded by the University of California Agriculture and Natural Resources’ Thelma Hansen Trust. — By Pamela Kan-Rice, UCANR

  • UCCE Investigates New Marketable Potato Varieties that Suit California Growers Well

    While the University of California does not have an official potato breeding program, the cooperative extension has close ties and collaborations with other universities and private companies that do, and Kern County has become quite the hub for trialing new potato varieties to determine whether they are suitable for the warm and dry climate of the West.  Jaspreet Sidhu, Vegetable Crops Farm Advisor heads up these informative trials and spoke with Matthew Malcolm on California Ag Network about the most recent results at her annual Potato Variety Trial Field Day. Watch this brief interview and read the full results in the current issue of California Fruit & Vegetable Magazine.