California Ag Network

Category: Weather

  • Hot March Results in a Lighter Pistachio Crop

    Hot March temperatures are leading to a lighter pistachio crop this year. However, growers and processors remain optimistic that the 2026 growing season is a fluke, and that the industry will have an excellent yield in 2027. Jeff Gibbons with Setton Farms and Joe Coelho with American Pistachio Growers discussed this anomalous year in the pistachio industry with Matthew Malcolm from California Ag Network. Watch this quick video and learn more in Pacific Nut Producer Magazine.

  • Researchers Requesting the Help of Pistachio Growers

    California pistachios now cover more than 600,000 acres and generate over $2.5 billion annually. As demand for pistachios continues to grow worldwide, production remains concentrated in the Central Valley with some acreage in coastal counties. However, a changing climate is creating new challenges for growers.

    Although the 2025–2026 winter felt “normal” with cold, foggy days, a closer look at the data shows that some pistachio orchards may not have received adequate winter chill. The March heatwave, which coincided with bloom, further intensified bloom and nut-set irregularities, issues many growers have already reported. However, some orchards were severely affected while others showed little or no impact, pointing to underlying factors that are not yet fully understood.

    This situation presents a valuable opportunity to better understand how unseasonable weather affects bloom, fertilization and set. To this end, the University of California, Davis (UCD) and the California Pistachio Research Board (CPRB) have developed a short grower survey. The information collected will help researchers evaluate the impacts of climate variability during this critical developmental stage. Several CPRB-funded research trials focused on improving yield and quality may also benefit from the survey data. These findings will help researchers develop strategies to prevent or mitigate similar impacts in the future and identify priority areas for targeted research. Grower participation is essential: the more orchards represented, the clearer the picture will be for guiding future research and management decisions.

    The California Pistachio Research Board encourages growers to complete the survey and share observations from their orchards this season. Growers with multiple orchards showing different performance under the same cultural practices (e.g. irrigation, fertilization) are welcome to submit separate responses for each site. The survey takes only a few minutes to

    complete but will provide valuable insights for future research.

    All responses are anonymous unless you choose to provide contact information. Growers can use the link or QR code below to access the survey.

    Pistachio Survey: https://forms.gle/vyeXgnoGfYG3aDDQ9

  • Why California is the Coldest State in the Nation

    At the annual Conference of the California Fresh Fruit Association, keynote speaker Nicola Twilley visited with Matthew Malcolm on California Ag Network to share insights the fresh produce industry in California can learn from a recent book she authored “Frostbite: How Refrigeration Changed Our Food, Our Planet, and Ourselves”. From the history of refrigeration and food preservation to the evolving consumer perception of what is considered fresh, watch this brief interview on an unexpectedly compelling topic.

  • Kings Watershed Snowpack Starts Season Well Below Average

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    SIERRA SNOWPACK CONDITIONS within the Kings River watershed are low, but marginally higher than last year. Those were the findings of this season’s first measurements by Kings River Water Association (KRWA) and other California Cooperative Snow Survey partners in the mountains of eastern Fresno and Tulare counties.

    Kings River Watermaster Steve Haugen said the snowpack water content is only about 8.8 inches, 52% of average for February 1, and represents only 32% of what would be expected when snow conditions typically peak around April 1.

    Snow depths averaged 32.5 inches this year compared with 53 inches in an average winter. Last year surveyors found about 2 inches less water content during the February 1 snow survey.

    Haugen said snowpack that typically melts in the spring, is the primary source of water for the Kings River, which provides surface water to irrigation districts and water users in portions of Fresno, Tulare, and Kings counties. “We had an early start to building our snowpack, with storms in November, then we entered a dry-spell that lasted most of January,” Haugen said. “Without additional storms, the Kings Basin snowpack could yield very-little river flow. We are hopeful for the current forecast of storms this week.”

    Of the 22 snow courses measured, the deepest snow was at Charlotte Ridge in the river’s South Fork near Mount Gould. There, the snow depth was 44.5 inches with a water content of 15 inches, 79% of average. The least snow depth — 7 inches — was at Ridge Trail, in Sequoia-Kings Canyon National Park.

    “We are in the middle of our biggest months for precipitation for California, and unfortunately January has been very dry, putting a significant dent in our season,” said California Department of Water Resources (DWR) Director Karla Nemeth. “A return to wet weather is critical for our season’s success and it will take many more storms to make up the deficit and further boost water supply deliveries.” Those are also the hopes of Kings River water users, who are watching the current storm and weather forecast closely.

    DWR will be using the snow survey along with information collected last week from Airborne Snow Observatory (ASO) flights to provide the Kings River water supply forecast. KRWA Assistant Watermaster Matthew Meadows said, “This detailed snow survey information collected by snow surveyors coupled with remote weather stations and ASO will give water managers the best accounting of snowpack conditions and expected water supplies.” Snow survey teams are already preparing for another trip to the high-country scheduled for the end of the month.

  • Ag Workers Reduce Hours or Move Locations to Avoid Wildfire Smoke

    Millions of cell tower pings from dating, weather, messaging and other mobile apps that use location-sharing services are helping agricultural economists better understand how farmworkers respond to environmental hazards such as wildfire smoke.

    During California’s most destructive wildfire season in 2020, the number of farmworkers in a surveyed field fell by nearly 35% and the number of hours worked in that same location dropped by 37% on smoky days when elevated levels of particulate matter were in the air.

    On less smoky days, the number of workers in surveyed fields was nearly 18% below typical levels and the hours worked were 23% below normal, according to novel research from the University of California, Davis, to be published in the January edition of Journal of the Association of Environmental and Resource Economists.

    “When this smoke is really heavy there’s a large reduction in the amount of people in a field in day,” said Tim Beatty, chair of the Department of Agricultural and Resource Economics and the senior author on the research.

    The researchers also found that farmworkers tended to work more hours in the days leading up to smoke events and switched fields to avoid the worst conditions.

    “We could figure out very rich hourly information of where these farmworkers went and if they moved to another location,” said Goeun Lee, a postdoctoral scholar and lead author on the journal paper. “This is kind of the first application of this data to answer some important questions in agricultural economics.”

    A new resource

    The research represents a new way of gleaning information about one of California’s most elusive workforces – farmworkers who harvest crops that help feed the nation – that conventional sources cannot quantify.

    “The results are relevant for policy makers seeking to protect workers health, safety and well-being and to ensure the sustainability of one of the most productive agricultural regions in the world,” the authors wrote.

    Lee and Beatty used crop field boundaries to define agricultural crop locations, overlayed smoke plume and weather data to determine environmental conditions and accessed cell phone data from a company that collects location information from about 400 mobile applications.

    They identified time, place and movement data of cell phones at the field level from January to mid-October for 12,667 crop workers – representing 8% of the agricultural workforce in California – and a sample size 20 times that of the federal National Agricultural Worker Survey of 2020, which is a main but limited point-in-time resource for tracking this population.

    “We don’t do a good job of collecting data on these pretty marginalized groups who are very important, so it’s very hard for us to say anything about policies that affect them because they don’t turn up in the data,” Beatty said. “This mobility data is interesting and important to really answer questions about a group of people who are underrepresented in surveys.”

    Shocks on the horizon

    Major wildfires and other environmental shocks are projected to become more frequent and current protections may not be adequate to protect farmworkers and their financial health, the authors said.

    “Farmworkers primarily work outdoors and they’re exposed to many environmental shocks and factors that can affect their health and productivity negatively,” Lee said. “Climate change is expected to increase the frequency of wildfire smoke and California relies a lot on this labor force. They are essential for California agriculture.”

    Wildfire smoke can cause fatigue, dizziness, headaches, confusion and other symptoms that increase the risk of injury. The researchers defined high smoke days as those with 40 micrograms per cubic meter of particulate matter. California regulations require workers to wear protective gear like respirators, alter their schedule or work in an area with better air quality when particulate matter is 55.5 micrograms per cubic meter.

    The short harvest season coincides with more intense wildfire months, which means farmworkers could lose wages while avoiding smoke hazards. “We should worry about people’s health but also their ability to earn a living because that also impacts their health and wellbeing quite directly,” Beatty said.

    Future studies

    The research has some limitations related to who made decisions related to smoke.

    “It could be as simple as farmers have multiple fields and they just switch the field they’re harvesting that day. It could be they work for a farm labor contractor and they just basically change the client they are working for that day,” Beatty said. “That sets the table for a lot of future questions.”

    The methodology could be used to answer future labor, environmental and agricultural economics questions and the authors are using cell phone data to track farmworker movement and behavior during extreme heat events and after pesticide use.

    “This kind of new data set that we made can be a valuable resource to answer other questions about farmworkers,” Lee said.

    The research was funded by the USDA National Institute of Food and Agriculture. — By Emily C. Dooley, UC Davis

  • Extreme Weather Accelerates Nitrate Pollution in Groundwater

    Extreme weather spurred by climate change, including droughts and heavy rains, may increase the risk of nitrates from fertilizers ending up in groundwater, according to a recent study from researchers at the University of California, Davis. The study found heavy rains after a drought caused nitrates to seep 33 feet under farm fields in as little as 10 days. The study was published in Water Resources Research.

    “The conventional wisdom was that it could take several weeks to years for nitrates to move from the crop root zones to reach groundwater,” said corresponding author Isaya Kisekka, a professor in the Departments of Land, Air and Water Resources and Biological and Agricultural Engineering. “We found these extreme events, such as California’s atmospheric rivers, are going to move nitrate more quickly.”

    In this study, different methods were used to measure how much nitrate, a component of nitrogen fertilizer, was seeping down through the soil in a tomato and cucumber crop near Esparto, California. Scientists conducted their research from 2021 until 2023 when California was experiencing periods of drought followed by atmospheric rivers. They measured nitrate during both the growing seasons and the rainy seasons.

    Drought can leave more nitrogen in soil

    Previous studies have shown about 40% of nitrogen fertilizer used for vegetables isn’t absorbed by the plants but remains in the soil. During droughts, crops don’t use nitrogen efficiently, leading to excess nitrogen in the soil. This study found that if a drought is then followed by heavy rainfall, that sudden burst of water causes nitrate to seep in groundwater more quickly. The nitrate concentration in the shallow groundwater exceeded the U.S. Environmental Protection Agency maximum contaminant level of 10 milligrams per liter for drinking water.

    “In California, we often say we swing between droughts and floods,” said Kisekka. “These extreme events that come with climate change are going to make the risk of these chemicals ending up in our drinking water much more severe.”

    Groundwater is the primary source of drinking water for most of California’s Central Valley. In some regions, such as the Tulare Lake Basin, nearly one-third of drinking and irrigation wells exceed the EPA’s safe nitrate level. High nitrate levels in drinking water can increase health risks, especially for young children. It may also increase the risk of colorectal cancer.

    Need for real-time soil nitrate monitoring

    Central Valley farmers are required to report to the Regional Water Board how much nitrogen they applied to their field and how much was removed as part of the crop’s yield. The study compared different ways of monitoring when nitrate from fertilizers seep into groundwater. Kisekka said the results highlight the need for affordable, real-time soil nitrate monitoring tools to help farmers manage fertilizer use efficiently.

    By using conservation practices that limit leftover nitrates in the crop’s root zone after harvest, farmers can help reduce nitrate contamination in groundwater.

    This study’s data will also help improve a model called SWAT, which is used to track nitrate seepage into groundwater across California’s Central Valley. This effort is part of the Central Valley Water Board’s program to regulate irrigated farmlands.

    Other UC Davis authors include Iael Raij Hoffman, Thomas Harter and Helen Dahlke.

    The study was supported by the USDA Natural Resource Conservation Service through its Conservation Effects Assessment Project. The national project is designed to assess the effectiveness of conservation practices across different watersheds. The study also had support from the USDA National Institute of Food and Agriculture. — By Amy Quinton, UC Davis

  • Ag Processing Labor Contractor Thoughts on New Indoor Heat Illness Rule

    California has experienced an unusually hot Summer this year, which may have had influence in Cal/OSHA’s recent approval of a new regulation “Heat Illness Prevention in Indoor Places of Employment” that went into effect immediately, which impacts indoor workplaces in ag such as nut hulling and processing facilities, wineries, dairies, packinghouses and more. Key indoor temperature/heat index thresholds of 82 & 87 degrees F will mandate certain procedures to ensure the health and safety of employees. Looking into the impact of the new regulation, Matthew Malcolm visited with labor contractor Robert Heredia of H&R Labor, who specializes in meeting the labor needs of food processing facilities in one of the hottest regions in the nation — the Central Valley of California. Watch this brief interview as Heredia shares his thoughts on the recent changes.

    Special thanks to American Pistachio Growers for sponsoring this video.

  • Avocados Get Hot — 4 Things to Consider Next

    It’s been hot and there is leaf damage. Those damaged leaves can protect the tree now and the fruit. Don’t prune the trees until you see the full extent of the damage and can still use those dead leaves to protect the rest of the tree.
    Fruit drop happens soon after, or slowly, depressingly over several weeks after a heat wave. The stem turns brown, cutting off moisture to the fruit, and they drop.

    If you see significant leaf drop in your groves due to excessive heat, the following actions are recommended:

    • As soon as possible, whitewash branches exposed to the sun with special attention paid to branches on the west and south sides of the tree.
    • Trees that lose a significant portion of leaves cannot efficiently move water, therefore restrict irrigation amounts to ensure you avoid creating wet, soggy conditions that can lead to root rot. It’s best to irrigate less frequently and with smaller amounts of water.
    • Do not prune your trees — leave hanging leaves in place to protect the tree from sunburn. Once new tree growth has occurred (in the next 3 – 6 months), pruning can take place on living wood.
    • Adjust fertilization as you would with a frost-damaged tree: reducing the amount of fertilizer until the tree is re-established. If you see signs of a particular nutrient deficiency, adjust fertilization accordingly.— By Ben Faber, UC Cooperative Extension

  • Kings Watershed Snowpack Still Below Average Despite Recent Storms

    Sierra Snowpack Conditions within the Kings River watershed have improved in February 2024, with several storms delivering snow and rain to the region. Snow surveyors are collecting samples in the high elevations of eastern Fresno and Tulare counties for the California Cooperative Snow Survey.

    Kings River Watermaster Steve Haugen shared that initial results show snowpack water content is about 18 inches, 77% of average for March 1, and represents only 68% of what would be expected when snow conditions typically peak around April 1.

    Snow depths averaged about 60 inches this year compared with 67 inches in an average winter.

    Prior to February, the frequent winter storms had not delivered much snow. However, several storms in February have provided about 10 more inches of water content than snow surveyors found at the end of January. This winter snowpack is critical water supply for downstream San Joaquin Valley water agencies and users in portions of Fresno, Tulare, and Kings counties for whom the Kings River is the primary source of water.

    “February 2024 precipitation in the region is about 160 percent above average.” Haugen said, “The snowpack water content has more than doubled in the past month. However, in March we will need to have at least 7 inches precipitation in the basin to be at average conditions before spring snow melt starts.”

    The deepest snow was at Upper Burnt Corral in the northern portion of the watershed. There, the snow depth was 84 inches with a water content of 25 inches, or 83% of the March 1st average. The least snow depth — 35.5 inches — was at Ridge Trail in Sequoia-Kings Canyon National Park.

  • Over $3 Billion Announced for Commodity & Specialty Crop Producers Impacted by 2022 Natural Disasters

    The U. S Department of Agriculture (USDA) will provide more than $3 billion to commodity and specialty crop producers impacted by natural disaster events in 2022. Eligible impacted producers can apply for financial assistance through the Emergency Relief Program (ERP) 2022. The program will help offset the financial impacts of crop yield and value losses from qualifying disasters occurring in 2022.

    “2022 was another year of weather-related challenges — for some, the third consecutive year or more in a row. The financial impact to a family farm or ranch in one year is significant but the cumulative impact of multiple years can be devastating,” said USDA Farm Service Agency (FSA) Administrator Zach Ducheneaux. “In our continued commitment to improving our delivery of emergency relief assistance, we have further refined our Emergency Relief Program 2022 delivery process. Instead of two separate program phases, we will now run two tracks concurrently increasing our efficiencies in application and payment processing while ensuring equitable program delivery. We also listened to important input from producers and stakeholders and have enhanced ERP 2022 provisions to ensure shallow loss impacts on revenue are considered.”

    Background

    On Dec. 29, 2022, President Biden signed into law the Disaster Relief Supplemental Appropriations Act, 2023 (P.L. 117-328)that provides about $3.7 billion in financial assistance for agricultural producers impacted by eligible natural disasters that occurred in calendar year 2022.

    ERP 2022 covers losses to crops, trees, bushes and vines due to qualifying, calendar year 2022 natural disaster events including wildfires, hurricanes, floods, derechos, excessive heat, tornadoes, winter storms, freeze (including a polar vortex), smoke exposure, excessive moisture, qualifying drought and related conditions.

    ERP 2022 program benefits will be delivered to eligible producers through a two-track process. FSA intends to make both tracks available to producers at the same time. This two-track approach enables USDA to:

    • Streamline the application process.
    • Reduce the paperwork burden on producers.
    • Proactively include provisions for underserved producers who have not been well served by past emergency relief efforts.
    • Encourage producer participation in existing risk management programs to mitigate the impacts of future severe weather events.

    It’s important to note that disaster-impacted producers may be eligible for ERP 2022 assistance under one or both tracks. To avoid duplicative benefits, if a producer applies for both tracks, the Track 2 payment calculation will take into account any payments received through Track 1.

    ERP 2022 Application Process – Track 1

    ERP 2022 Track 1 leverages existing federal crop insurance or Noninsured Crop Disaster Assistance Program (NAP) data as the basis for calculating payments for eligible crop producers who received indemnities through these risk management programs.

    Although FSA is sending pre-filled ERP 2022 Track 1 application forms to producers who have crop insurance and NAP data already on file with USDA, producers indemnified for losses resulting from 2022 natural disasters do not have to wait to receive the application before requesting ERP 2022 assistance. Effective Oct. 31, 2023, producers can apply for ERP 2022 benefits whether they have received the pre-filled application or not. Receipt of a pre-filled application is not confirmation that a producer is eligible to receive an ERP 2022 Track 1 payment.

    USDA estimates that ERP Track 1 benefits will reach more than 206,000 producers who received indemnities for losses covered by federal crop insurance and more than 4,500 producers who obtained NAP coverage for the 2022 crop year.

    ERP 2022 Application Process – Track 2

    Track 2 is a revenue-based certification program designed to assist eligible producers who suffered an eligible decrease in revenue resulting from 2022 calendar year disaster events when compared with revenue in a benchmark year using revenue information that is readily available from most tax records. In cases where revenue does not reasonably reflect a normal year’s revenue, Track 2 provides an alternative method for establishing revenue. Likewise, Track 2 affords producers of crops that are used within an operation and do not generate revenue from the sale of the crop a method for establishing revenue for the purpose of applying for ERP 2022 benefits. Producers are not required to submit tax records to FSA unless requested by the County Committee if required for an FSA compliance spot check.

    Although not required when applying for ERP 2022 Track 2, applicants might find the following documents useful to the process:

    • Schedule F (Form 1040)
    • Profit or Loss from Farming or similar tax documents for tax years 2018, 2019, 2022 and 2023.

    Track 2 targets gaps in emergency relief assistance for eligible producers whose eligible losses were not covered by crop insurance or NAP including revenue losses too small (shallow loss) to be covered by crop insurance.

    Producers interested in applying for ERP 2022 Track 2, should contact their local FSA county office.  Additional reference resources can be found on FSA’s emergency relief website.

    Additional Required Forms

    For both ERP 2022 tracks, all producers must have certain required forms on file with FSA within 60 days of the ERP 2022 deadline. Producers can apply for ERP 2022 starting Oct. 31, 2023. The application deadline has not yet been determined and will be announced at a later date. If not already on file, producers can update, complete and submit required forms to FSA at any time.

    Required forms:

    • Form AD-2047, Customer Data Worksheet.
    • Form CCC-902, Farm Operating Plan for an individual or legal entity.
    • Form CCC-901, Member Information for Legal Entities (if applicable).
    • Form FSA-510, Request for an Exception to the $125,000 Payment Limitation for Certain Programs (if applicable).
    • Form CCC-860, Socially Disadvantaged, Limited Resource, Beginning and Veteran Farmer or Rancher Certification, if applicable, for the 2022 program year.
    • A highly erodible land conservation (sometimes referred to as HELC) and wetland conservation certification (Form AD-1026 Highly Erodible Land Conservation (HELC) and Wetland Conservation (WC) Certification) for the ERP producer and applicable affiliates.

    Most producers, especially those who have previously participated in FSA programs, will likely have these required forms on file. However, those who are uncertain or want to confirm the status of their forms can contact their local FSA county office.

    Future Insurance Coverage Requirements

    All producers who receive ERP 2022 payments must purchase crop insurance, or NAP coverage where crop insurance is not available, in the next two available crop years as determined by the Secretary. Purchased coverage must be at the 60/100 coverage level or higher for insured crops or at the catastrophic coverage level or higher for NAP crops.

    More Information

    ERP 2022 eligibility details and payment calculation factor tables are available on the emergency relief website, in the ERP Track 1 and ERP Track 2 fact sheets and through your local FSA county office.