It’s been a while since California growers have experienced a wet year with a plentiful snowpack and water supply. Weather conditions this season, though, have pushed harvest back for most grape growers and powdery mildew pressure has been unusually high for growers that didn’t stay on their spray programs with just the right timing. Watch this brief interview with UCCE Viticulture Farm Advisor George Zhuang as he explains, and read more about it in American Vineyard Magazine.
The thought of losing freedom sounds awful; however when it comes to the grapevine ‘Freedom’ rootstock, it may be a good idea, particularly for growers in the San Joaquin Valley. Watch this brief interview with UCCE Viticulture Farm Advisor Karl Lund as he explains why and explores alternative options.
Please thank this video’s sponsor Ranch Systems for their industry support.
As if there weren’t enough trunk diseases impacting California vineyards, UC Davis Plant Pathologist Akif Eskalen has been researching a newly identified disease causing a canker on the trunk of grapevines accompanied by fruit disease/sour rot symptoms. Watch this brief interview with Akif, and read more about it disease management in American Vineyard Magazine
Please thank this video’s sponsor Ranch Systems for their industry support.
Due to severe water shortages, rice acres planted in California plummeted by 37% from 2021 to 2022, according to numbers released recently by the U.S. Department of Agriculture’s National Agricultural Statistics Service. But now, thanks to University of California researchers, growers have a new tool they could potentially use to cope with droughts and other environmental and socioeconomic changes.
A crop rotation calculator provides farmers in the Sacramento Valley – where 97% of California rice is grown – with projections on the economic impacts of transitioning their fields from rice into four less water-intensive crops: dry beans, safflower, sunflower or tomato.
The tool represents an initial attempt to address the dearth of research on rice crop rotation in California, while giving growers much-needed, science-backed data on whether the practice would make financial sense for their farms.
“I believe more rice growers could benefit from the many advantages of crop rotation, and this new tool is an excellent first step by the UC to help growers look into making such a transition,” said George Tibbitts, a Colusa County rice farmer.
Funded in part by the USDA National Institute of Food and Agriculture, through the Western Integrated Pest Management Center, the calculator is a collaborative effort of UC Agriculture and Natural Resources, UC Integrated Pest Management and UC Davis to fill a major gap in rice research.
“I do think there are people who would have tried rotational crops in the past, but it’s just so unknown, we didn’t have anything we could give them and be like, ‘Hey, this is the recommended crop for your area,’” said Whitney Brim-DeForest, UC Cooperative Extension rice advisor. “This tool gives them some preliminary data they can use to make a more informed decision.”
Crop rotation a potential boon to growers, environment
UC Davis doctoral student Sara Rosenberg and Brim-DeForest, alongside other members of the UC rice research team, surveyed California rice growers in 2020 on their experiences with and perceptions of crop rotation. Although the practice is rare in the Sacramento Valley (only an estimated 10% of rice acreage is under rotation), some farmers reported benefits that could be crucial in a water-scarce future.
“From having conversations with growers who do rotate, one of the biggest benefits they describe is their flexibility in times of drought, where they can keep producing on their land when there isn’t enough water to grow rice,” said Rosenberg, noting that crop rotation could be one option in a “toolbox” of strategies that growers also use to manage fertilizer price shocks, herbicide resistance and other challenges.
Given the dearth of quantitative data on crop rotation in rice, more studies are needed on the practice in California, according to Whitney Brim-DeForest, UCCE rice advisor. Photo by Evett Kilmartin
During the ongoing drought that caused about half of California’s rice acreage to go fallow in 2022, Tibbitts said his water district was only able to allocate 10% of his usual allotment.
“With such a limited supply, it would have been tough to grow even one field of rice,” he said. “But it was enough water so that we could rent two of our fields to a tomato grower – tomatoes under drip irrigation use much less water than a flooded field of rice. We were also able to grow one field of sunflowers, which doesn’t need any irrigation at all if you can plant the seeds into existing moisture in the early spring.”
While drought is one motivating factor to rotate crops, Tibbitts said that on principle he avoids planting all his acreage in rice and “not have all (his) eggs in one basket.”
“My primary motivation for rotating into and out of rice has been to help with weed and disease control,” he added. “Crop rotation is a primary tool of IPM (integrated pest management), and I feel it has helped me greatly over the years.”
According to Brim-DeForest, rotating cropping systems can allow for the use of different weed control tools, such as different herbicide modes of action, and different cultural controls such as tillage, reducing the chances of selecting for herbicide-resistant weeds – an increasingly pervasive issue in rice systems.
Rosenberg noted that, in some situations – and depending on the crops in rotation – the practice can also disrupt the life cycles of insects and diseases and potentially improve soil structure and increase nutrient cycling and uptake, which may lead to a reduction in inputs such as fertilizer.
More research on crop diversification needed in rice systems
The benefits of crop rotation for California rice growers are largely theoretical and anecdotal, however, so the UC rice team is looking to add evidence-based grounding through a variety of studies – from looking at long-term effects on soil health indicators to testing various cover crops (which may deliver some benefits of diversification, similar to those of rotation).
In addition to crop rotation in rice, researchers are also studying cover cropping, which may deliver some benefits of diversification, says UC Davis doctoral student Sara Rosenberg.
“In California, there is no quantitative data on crop rotation in rice,” said Brim-DeForest. “You’d think after a hundred and some odd years (of UC agricultural research), all the research would have been done, but, no – there’s tons still to do.”
Through interviews with Sacramento Valley growers, researchers found that cost was frequently mentioned as a barrier to trying crop rotation, along with incompatible soil conditions and a lack of equipment, knowledge and experience.
To help clarify those economic uncertainties, the new calculator tool allows growers to enter baseline information specific to their circumstances – whether they rent or own their own land, whether they contract out the work to plant the rotational crop, and other factors. The calculator then generates potential costs and benefits of staying in rice versus rotating to dry beans, safflower, sunflower or tomato, during the first year and in an “average” year for those crops.
The upfront costs of rotation during “year one” can be daunting. Therefore, the tool only focuses on a short-term profitability perspective. Researchers are currently working on longer term modeling for crop rotation – incorporating the possibility of reduced herbicide use over time, and under different crop yield scenarios, for example – that could significantly change the growers’ calculus.
“You could actually be profitable in the long term, whereas this first, short glimpse is showing you a negative,” said Rosenberg.
In addition, thanks to collaboration with the UC IPM team, the rice rotation calculator is an evolving tool that will be continually improved based on user feedback and additional data. Brim-DeForest also said that it could be adapted to other cropping systems – for example, alfalfa going into another rotational crop.
Other contributors to the project include Bruce Linquist, Luis Espino, Ellen Bruno, Kassim Al-Khatib and Michelle Leinfelder-Miles of UCCE; Cameron Pittelkow of UC Davis; as well as UC IPM team members Chinh Lam, Tunyalee Martin and Hanna Zorlu; and the California rice growers and industry members who participated in the research. — By Mike Hsu, UCANR
UC Agriculture and Natural Resources brings the power of UC to all 58 California counties. Through research and Cooperative Extension in agriculture, natural resources, nutrition, economic and youth development, our mission is to improve the lives of all Californians. Learn more at ucanr.edu and support our work at donate.ucanr.edu.
To teach PCAs about citrus mealybug (an emerging concern for citrus growers) this field day will focus on lectures on pest identification and biology, scouting/monitoring, and management, lecture on ant control. With this knowledge, PCAs can monitor the fields for mealybug infestation and develop informed management strategies. Attendees will receive instruction from Sandipa Gautam and David Haviland from the UC Cooperative Extension. The field day will take place in a citrus block in Ivanhoe, CA. Growers can register to attend by April 21 HERE, or by emailing sangautam@ucanr.edu. Attendees should bring a 10x hand lens. An email will be sent out with a location ping to registrants 1-week prior to the event. 3 hours of Other Continuing Education Units are pending approval with CDPR.
AGENDA
8:00 a.m. Registration: Ivanhoe citrus block
8:30-9:30 am
Introduction: The citrus mealybug problem and best management practices (chemical, biological).
Seasonal phenology and monitoring males using pheromone lure (Georgina Reyes)
9:30 am: Sugar-feeding ants and their management in orchard systems
10:15 am: Microscope time: Identification of mealybug stages, and parasitism.
While there has been research and work underway to move the almond industry to off-ground harvesting such as is done in pistachios, harvested almonds currently spend just enough time in the dust of orchard floors that they can pick up trace residues of herbicides. Watch this brief interview with UC Cooperative Extension Weed Specialist Brad Hanson as he shares how growers can mitigate this risk with more effective weed management planning and timing of herbicide sprays.
Please thank this video’s sponsor Suterra for their industry support.
In December 2022, the University of California (UC) acquired a 114-acre farm property on the west side of Camarillo to become the new home of the Hansen Agricultural Research and Extension Center (HAREC), supported by an endowment bequeathed to the University of California by Saticoy farmer Thelma Hansen. The mission of the Thelma Hansen Fund is to support and maintain University research and extension activities for the sustainability and benefit of agriculture and natural resources in Ventura County.
For the past 25 years, the Center has been located on the historic Faulkner Farm in Santa Paula. At 27 acres, HAREC was the smallest of the nine research and extension centers operated by UC Agriculture and Natural Resources throughout California. For many years, it hosted a popular school field trip program, a Master Gardener demonstration and training garden, and numerous research trials on fruit and vegetable crops and landscape plants. In 2019, it was decided that the Center should move to a larger property on or near the Oxnard Plain to expand research and extension capacity. The Faulkner Farm was eventually sold in March 2021 but a portion was leased back to the University to maintain research and educational activities until a new location was identified.
A planning committee of agricultural stakeholders, UC and County staff, and external consultants embarked on the search for a new location and developed a provisional layout of the new facility. The search was complicated by a paucity of suitable farm properties for sale during that period. One of the desired features of the new site was a location on the Oxnard Plain in order to have a representative environment for doing research on high-value crops in Ventura County, such as strawberries. Other criteria were acreage, accessibility, having representative and diverse soil types, access to sufficient irrigation water of good quality, low risk of flooding, proximity to California State University Channel Islands (CSUCI), and municipal water and sewer access.
The new farm location meets most of our search criteria and is representative of the coastal agriculture environment. Various soil types are present at the site, including clay, clay loam, loam and loamy sand, suitable for a variety of crops. Of the approximately 104 cultivable acres, 28 are certified organic, which will allow us to do research on organic as well as conventional crop production methods in the future. The farm has two agricultural wells, a 7-acre yard area with several shop buildings, and is fully tiled and set up for irrigation. The land is currently used to grow strawberries and vegetables but was a lemon orchard in the past. A bonus is its proximity to the Rodale Institute California Organic Center, which will enhance opportunities for collaboration, as well as Sterling Hills Golf Course, which has banquet facilities for large events.
So, what are our plans now that we have found a new home for HAREC? Over the next 6 months, we will orchestrate the move from the Faulkner Farm to Camarillo, which will involve the transportation of two modular office buildings, a walk-in cooler, shed, various sea containers and all of our farm equipment, vehicles and tools. Seismic and other repairs will be needed at the new site before the buildings can be usable. Since a substantial part of the parcel is leased out for farming for the next three years, we will initiate and expand research projects and plantings on the remaining acreage.
Then the long process of designing a new research and educational facility will begin with the help of stakeholders, staff, architects and engineers. The new facility, which is expected to be completed in 4 to 5 years, will have offices, conference rooms, laboratories, greenhouses, storage space, a demonstration kitchen and indoor and outdoor education areas. The facility will aim to be water efficient and energy neutral, relying on solar panels for much of its energy usage. The new site is envisioned to have Master Gardener demonstration gardens, a Student Organic Farm in collaboration with CSUCI and the Rodale Institute, a pollination garden with beehives, and a Compost Training Center. Other ideas on the table are the establishment of a Biological Control Research Center for Southern California and possibly a Fire Science Laboratory. Eventually, the UC Cooperative Extension Office in Ventura will also move to the new site for administrative and programmatic efficiency.
The ultimate goal of the new Hansen Agricultural Research and Extension Center is to become a vibrant research and education hub that provides science-based solutions and is responsive to the needs of agricultural, rural and urban communities and the environment in Ventura County. Staffing levels will increase in order to expand current programming and bring new educational opportunities to the County, such as the UC Master Food Preserver and Master Beekeeper programs. A capital campaign will be needed to gather sufficient funds for the establishment of the facility. We look forward to gathering input on how to best fulfill our mission and future-proof the facility. — By Annemiek Schilder, UCANR
The removal of nuts remaining on almond trees from the prior year’s crop is an important winter sanitation practice for the management of navel orangeworm (NOW), Amyelois transitella. Residual nuts are called ‘mummies’ and the process of removing the mummies is referred to as a ‘mummy shake’ because they are mechanically shaken from trees. This practice is conducted during the dormant and delayed dormant season, a time when orchard access may be thwarted by the winter rains.
Most growers strive to have the mummy shake complete by mid-January when buds are dormant and less likely to abscise from the vibration caused by a mechanical shaker. As the flower buds progress toward bloom, they become more sensitive to the shaker vibration and more likely to abscise. Studies conducted in the 1980s (Sibbett et al.) established that the shaking of mummies by January 31 (approximately 8 days prior to bloom) at a Kern County site did not adversely affect yield; however, the authors cautioned growers of the risk of delaying mummy shakes further, particularly on early blooming varieties and in locations in the southern San Joaquin Valley. Because bud development and bloom date advance with increasing latitude, the potential risk of early and mid-February mummy shakes was investigated by W. Asai (Pomology Consulting, Turlock, CA) in the northern San Joaquin Valley. This work, conducted at a more northern latitude, suggested shakes conducted in early February may not compromise yield.
The lack of yield detriment attributed to a mummy shake-mediated bud loss may seem counterintuitive; however, simple concepts of tree physiology may help explain this phenomenon. Consider that only approximately 30% of the flowers on a tree set a crop. A given tree does not have the carbohydrate stores needed to set every flower. As a result, the loss of a subset of flower buds may have little effect on overall yield. Naturally, the risk of crop loss increases the closer the shake approaches bloom, and both research groups suggested that mummy shakes be complete prior to the pink bud stage of development.
Although rainy years make it difficult for growers to access orchards and complete orchard sanitation tasks, the heightened soil moisture adversely affects NOW survival in comparison to dry winters. Mummy nuts on the ground support enhanced NOW survival on a dry orchard floor than on moist soil with winter vegetation in the row middles. The next step in managing overwintering populations of NOW is destruction of mummies by flailing or mowing. Flailing and mowing should be completed by March 1, prior to the emergence of NOW. The emergence profile of NOW varies by location, but the first flight generally starts in late March.
Growers who have not completed their winter sanitation practices by the end of January should walk their orchards to assess bud development in consideration of a delayed mummy shake. Winter sanitation can reduce now damage by up to 80%, so an early February shake may be worth the effort if orchard access is possible and bud development has not advanced into pink tip. For more information on NOW management, visit www.ipm.ucdavis.edu. — By Cameron Zuber & Elizabeth Fichtner, UCANR
In addition to frost damage in the spring, San Joaquin Valley vineyards also experienced severe heat stress as well that took a toll on the crop. Watch this brief interview with UCCE Viticulture Farm Advisor George Zhuang as he shares how growers can better prepare their vineyards for future heat waves — as discussed at the recent Grape, Nut & Tree Fruit Expo in Fresno. Read more about it in American Vineyard Magazine.
Please thank this video’s sponsor Suterra for their industry support.
Vine mealybug has never been more widespread across the grape growing regions of California than it is now. Watch this video interview with Nathan Mercer from the Kent Daane Lab at UC Berkeley, who shares a more effective and collaborative way to control this pest in vineyards. Read more about vineyard pest management in American Vineyard Magazine.
Please thank this video’s sponsor Suterra for their industry support.
