UC Ag and Natural Resources will hold the 42nd International Carrot Conference, scheduled for June 2-3 at the Bakersfield Marriott Convention Center.
The Carrot Conference is an opportunity to share and discuss research findings and a way for people to exchange ideas and concerns in all aspects of carrot production. Topics such as breeding, new products, production, and pest management are discussed in formal paper sessions, poster sessions, and a field tour, as well as other social gatherings.
The conference also provides continuing education opportunities with 4.5 other DPR hours approved for June 2. More details and an agenda can be found here. For additional information please contact: Jaspreet Sidhu, Kern County Cooperative Extension, 661-868-6222, 661-304-8870. — Contributed by UC Ag and Natural Resources
Soil sampling is the first step toward effective control of plant-parasitic nematodes. These underground, microscopic worms, especially root-knot species, develop and feed on the root systems of young fruiting vegetables. Their feeding leaves visible galls on roots, which disrupt the plant’s ability to efficiently take up water and essential nutrients needed for healthy plant development.
A single acre of ground can harbor several hundred million nematodes. Because nematodes reproduce quickly, making control applications early in the cropping cycle is critical to protecting developing roots.
Fruiting vegetable growers can now put a nematicide with a new mode of action in their nematode control toolbox, offering a more favorable environmental profile than other products on the market today – Salibro® CA nematicide with Reklemel® active. Salibro CA is a true nematicide that selectively controls plant-parasitic nematodes and does not negatively impact free-living, or beneficial, nematodes, which play an important role in maintaining soil health.
Salibro CA nematicide is in a unique chemical group, making it a strong tool for resistance management and helping prolong the efficacy of all nematicides. It offers excellent compatibility with soil health, including with beneficial nematodes, soil fungi and soil bacteria. Let Salibro CA nematicide protect the roots of tomatoes and other fruits and vegetables for increased yield potential and more marketable crops at harvest.
The winter of 2024-2025 saw average precipitation for the Merced area, with 9.66 inches of rain based on the California Irrigation Management Information System (CIMIS) weather station in Ballico (Merced County no longer has any functioning CIMIS stations). A cool spring was followed by a mild summer, with only six days at or above 100°F. This great weather led to low plant stress and excellent yields. Overall production was even better than in 2023, which was likewise a good year due to mild summer temperatures.
The Collaborators Trial results reflected the successful production year — the standard lines exceeded 1400 boxes/acre, or about 70 bins/acre (Figure 1). Several Bellevue fields exceeded 80 bins/acre.
Rains came early during harvest, with 1.5 inches of rain falling on October 13, followed by another storm in November. The mid-October storm may cause some problems for the stored crop, especially if the Diane cultivar was still in the ground.Soil temperatures at 6 inches depth dropped 4°F after that rain. The combination of the soil being both cold and wet during harvest created the potential for accelerated decay in storage.
How Did the Different Cultivars Perform?
The Murasaki and Vermillion cultivars continue to have inconsistent set and erratic production.Zero carryover from last year resulted in high prices for Murasaki in August and September. Farm advisor Scott Stoddard guesses that many fields were harvested early to take advantage of the price at the expense of yield, which means a short crop is likely in summer of 2026.
Vermillion quality and yield vary.The plants seem to set too many roots that never fully develop. That is why Stoddard continues to screen new reds, with three potential new releases in the pipeline.
The market for purple-flesh sweet potatoes continues to grow and command good prices. In the last two years, new purple-flesh cultivars have yielded well — over 35 bins/acre — in Stoddard’s trials.They are attractive, with good shape and skin color. Cultivar L-24-71p looks especially promising in its first year, with deep purple flesh and good flavor and texture. It may soon join the six purple cultivars already commercially available: Stokes, Ben Yagi, Regal Purple (USDA ARS), Purple Majesty (NCSU), Purple Splendor (NCSU) and Purple Reyne (LSU), grown on about 1000 acres total.
Total marketable yields in boxes/acre differed widely among cultivars and among years. Covington had the highest 4-year total and Vermillion had the lowest.
Diseases Remain Problematic
Despite the good growing season, certain diseases remain problematic. Fusarium root rot (putatively Fusarium oxysporum+ F. solani) mainly impacts Bellevue, though the other cultivars are not immune.Scurf — a superficial, soil-borne fungal disease — impacts Covington, but also can infect the other cultivars. Southern blight is mostly a problem in Diane in the hotbeds, but it can likewise damage any variety.
New work by UC Davis plant pathologist Cassandra Swett shows that the organism responsible for Fusarium foot rot may not be F. oxysporum at all, but rather the newly named Fusarium noneumartii, formerly lumped in with F. solani f.sp. batatas.
Fusarium foot rot first appeared as a major problem in 2022 during harvest, causing 10-20% loss on some fields harvested in October, after a September heat spell with several days above 105°F and a record high of 112°F on September 6. The roots rotted while still in the ground. No such heat conditions occurred in 2025, which makes the high incidence of this disease worrisome. No doubt it has been around for decades, but why it has suddenly become so prevalent is not known.
The reason for the increase in scurf, however, is most likely because of reduced use of clean seed these last few years. Scurf is easily transferred from cuttings to transplants, but does not live long in fields in the absence of sweet potatoes.“One year out and it’s gone,” Stoddard comments.
Suggested management practices for both Fusarium root rot and scurf include using thiabendazole (Mertect) fungicide in the hotbeds, using clean seed, cutting transplants above the soil line, managing nematodes and timely harvest — the longer the roots are in the ground the more likely they will become infected.
What is the acreage and production of sweet potatoes in California?
The USDA has revised their estimates for sweet potato production acres in California:
year
acres
2020
22,000
2021
21,000
2022
21,000
2023
19,000
2024
18,000
At 29.5 bins/acre average yield and 18,000 harvested acres, total production in 2024 was around 530 million pounds. USDA has not yet published estimates for 2025, but Stoddard estimates 18,000 acres at 35 bins/acre, for total production of 630 million pounds.
What’s Happening in Sweet Potato Research?
Variety Trials
The National Sweetpotato Collaborators Group trial is a variety trial that is conducted in multiple states.It provides regional information to plant breeders at Louisiana State University, North Carolina State University and USDA. The national results, shown in Figure 1, show that the yields vary widely among cultivars and over the years.Covington had the highest four-year total and Vermillion had the lowest.
The results of Stoddard’s 2025 Advanced Line Trials (ALT) in Merced, an expanded version of those conducted each year with Dave Souza, are presented in Figure 2. Notice how Beauregard yielded over 100 bins/acre, but was mostly jumbos (only 21% #1’s).Bellevue stands out as having both high yield and a high percentage of #1’s. Stoddard used greenhouse plant cuttings straight from Foundation Plant Services, which illustrates the tremendous yield increases possible when using new seed.
Advanced Line Trials (ALT) for 2025 showed Bellevue having both high yield and a high percentage of #1’s.
Fumigation and Nematicide Trials
Stoddard continued his evaluation of various nematicides in 2025 with an emphasis on placement and timing. The Salibro label, updated in 2025, prescribes different methods than the ones he has used for several years, limiting applications to pre-plant and 30 days after transplanting.
The experiments were conducted in hotbeds in 2023 but in fields in 2024. Even in fields, root knot nematode (RKN) counts were very low and remained so throughout the entire season. The field was fumigated in April, planted May 1 with Diane (RKN susceptible) and harvested September 17-19, 2025. Nimitz and Nemaclean nematicides were pre-plant incorporated one week before transplanting, while all the others were applied post-plant in May and June.
One of the Velum treatments was applied in the row by moving the tape over to the plants and then injecting. This position was chosen because Velum has low solubility and does not move well in soil, so direct placement near the plants may improve efficacy. A Velum-then-Salibro trial was also evaluated.
The nematicide results are shown in Figure 3. Overall, this was a high-yielding field with low nematode pressure.Nonetheless, yields were significantly higher in all the nematicide treatments than in the untreated control by an average of 8 bins/acre. The specific nematicides did not differ significantly from each other.
Farm advisor Scott Stoddard’s sweet potato nematicide trial in Merced County in 2025 showed that yields were higher in the plots receiving nematicide than in the control plots with no nematicide, even in a year with low nematode pressure. The nematicides did not differ significantly from each other.
The big news is that Covington comes off patent in May. The high-yielding variety was released by NC State in 2005. — By Scott Stoddard, UCCE Farm Advisor, Merced and Madera Counties and edited by Nancy Power, PHD, Assistant Editor for California Fruit & Vegetable
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.
California is far from being the top producer of potatoes; however the Golden State is unique in its ability to cultivate potatoes year-round with four major (and diverse) growing regions. Potato harvest is well-underway in California for some growers, while it’s still a little ways off for process potato grower Jason Selvidge of Buttonwillow Land & Cattle. California Fruit & Vegetable Editor Matthew Malcolm met with this member of the California Potato Research Advisory Board at UCANR’s recent Potato Variety Trial Field Day in Kern County. Watch his brief interview as he shares his outlook for California’s potato crop this year and read more in California Fruit & Vegetable Magazine.
The Annual UC Cooperative Extension and California Potato Research Advisory Board Variety Trial Field Day is an opportunity to see tubers of potentially new varieties, how they performed this year, and how they performed compared to standard varieties. Entries include varieties from numerous USDA, state, and private breeding programs. This year’s entries include Russets, chippers, reds, yellows, and specialty types. Tubers will be shown as how they look straight from the field after being washed. This is an opportunity to express your evaluations and recommendations about these varieties to University researchers, breeders, seed growers, and fellow growers.
The Field Day will take place on Wednesday, June 11, 2025, 10a.m. to 12:30p.m.
LOCATION! The Potato Field Day will be held in the shade near the bank of the Kern River at HART PARK. It will be located on the east end of the park in Section 2, just off Alfred Harrell Highway. Please see map on back for directions to Hart Park. Snacks and refreshments will be available.
Potato Grower Meeting: You should be receiving a notice from the CPRAB for the annual potato grower’s dinner and informal meeting to be held the evening of the field day.
For further information contact:
Jaspreet Sidhu, Kern County Cooperative Extension, 661-304-8870
Nathan Sano, California Potato Research Advisory Board, 559-591-0436
In October 2024, the Government of Japan (GOJ) added a genome edited potato to the list of genome edited products not subject to regulations for genetically engineered food and feed. This is the seventh genome edited product added to the list and the second product developed a by a non-Japanese company. The U.S. company, J.R. Simplot Company, developed the potato product using CRISPR-Cas9 technology to have a high tuber set.
General Information:
The J.R. Simplot Company developed a genome edited potato product using CRISPR-Cas9 technology to knock out the “Gn2” gene by deleting 110 base pair, which resulted in a higher tuber set. In October 2024, Japan’s Consumer Affairs Agency (CAA) 1 and the Ministry of Agriculture, Forestry and Fisheries (MAFF) regulatory authorities added the potato to the list of genome edited products that are not subject to Japan’s GE food and feed regulations. For more information, see CAA’s website for Food Safety information, and MAFF’s website for Feed Safety information (Japanese only). As Japan restricts the import of U.S. fresh potatoes due to plant health sanitary and phytosanitary concerns, MAFF considers a biodiversity notification unnecessary.
Background:
The CAA and MAFF request that all developers and/or companies that seek regulatory review of genome edited products in Japan undergo a consultation and notification process prior to commercialization in Japan. See JA2020- 0184 for additional details about the policies and procedures for genome edited foods and agricultural products.
As of March 2025, CAA and MAFF have seven products to their lists of genome edited products that are not subject to Japan’s GE food and feed regulations, including two tomatoes with high GABA content, a high-yield seabream fish, a fast-growing tiger pufferfish, waxy corn, a fast growing olive flounder, and the high-tuber potato. — By Suguru Sato, USDA Foreign Ag Service
Navigating the consumer path to purchase can be complex, influenced by a countless factors. A new Potato Path to Purchase study from Potatoes USA uncovers key insights into consumer behavior and purchase patterns, offering a deeper understanding of the pre-shopping and in-store experiences that drive potato purchases. In addition to revealing the most recent data, the study provides actionable steps retailers can take to help drive potato sales.
“Potatoes are a staple in consumers’ kitchens. They earn a place on the table whether it’s a casual Wednesday night or a Thanksgiving feast, and consumer favorability for potatoes translates to valuable opportunities for retailers,1” said Kayla Vogel, senior global marketing manager at Potatoes USA.
Consumers note quality, price and quantity are the top three potato purchase factors.
The Consumer Path to Purchasing Potatoes study, fielded by Nielsen IQ, found that shoppers’ path to purchase potatoes is mostly influenced by three key factors with over 90% of potato purchases being pre-planned.
“Ranking purchase factors, freshness/quality receives the top rating, ahead of price1,” Vogel said. “For retailers, it is important to highlight freshness, including tips on how to best store potatoes at home to optimize shelf life and prevent unnecessary food waste.”
According to the study, 84% of consumers want transparent bags1 so they can gauge freshness and quality for themselves. Vogel emphasizes merchandisers should create eye-catching displays with quality products and inspiration to try new potato recipes and varieties.
“In-store, visual displays and inspirational signage drive influence more than discounts and promotions. As budgets tighten, people have remained loyal to potatoes. That means there are opportunities to significantly achieve scaled results through improved visibility, merchandising and cross-merchandising.”
Potato purchasing decisions are driven by planned meals.
Pre-store, there are numerous high-impact influences on consumer purchasing decisions, including:
Price and promotions in circular flyers.
Recommendations from family and friends.
YouTube recipes.
Products in cookbooks.
Shopping list apps.
Ads in magazines or newspapers.
“Meal planning significantly influences pre-trip purchases with 90% of purchases being pre-planned,1” noted Vogel. “It’s important to integrate potatoes into recipe suggestions to optimize their inclusion on consumers’ grocery lists and prioritize pre-store touchpoints to influence consumer decisions.”
80% of respondents plan which potato type they will buy with more than 44% going directly to the planned type in-store.
“In-store buying decisions are predominantly swayed by point-of-purchase displays,” added Vogel. “Retailers and merchandisers can enhance the in-store experience through larger displays, secondary locations, inspirational signage and ensuring potatoes are readily accessible within the store.”
89% of consumers believe potatoes are versatile and easily adapted to many different types of dishes.1
“To inspire mealtime with potatoes, provide on-pack and shelf inspiration to show how potatoes can be used in the meal lineup multiple times a week without eating the same thing twice,” noted Vogel. “It’s also important to highlight new ways of using common varieties in special ways as well as expand on special occasions to increase sales.”
1Nielsen Consumer LLC, Consumer Path to Purchase Potatoes Study 2023
About Potatoes USA
Potatoes USA is the national marketing and promotion board representing U.S. growers and importers. Potatoes USA, the largest vegetable commodity board, was established in 1971 by potato farmers to promote the benefits of eating potatoes. For more information on Potatoes USA’s mission to “Strengthen Demand for Potatoes,” visit PotatoGoodness.com.
Tubers of four Russet potato cultivars (Russet Burbank, Umatilla Russet, Bannock Russet, Dakota Russet) are being monitored under controlled environmental conditions for dormancy progression and sprout growth patterns during postharvest storage. (Photo by Munevver Dogramaci, USDA-ARS, Fargo, ND.)
Scientists at the USDA’s Agricultural Research Service (ARS) use innovative technology to study the lifecycle of potatoes (including development, production, and postharvest storage), ensuring a high-quality supply year-round for snack food processing facilities, restaurants, and grocery stores.
Potatoes are one of the main crops grown in the U.S., with a production of approximately 22.5 million tons annually. Fall is the primary season for harvesting potatoes, accounting for 90 percent of the total production. Since many locations cannot support year-round potato cultivation, most potatoes intended for processing, such as frozen french fries or instant mashed potatoes, are harvested in the fall and safely stored until needed. Storing and maintaining potatoes at their top nutritional quality while meeting consumer and market demands is essential for the industry.
Yet, potato producers face several critical challenges, including climate- and disease-related challenges during crop production and long-term storage. Maintenance of post-harvest quality is of prime concern to the potato industry because post-harvest crop losses through physiological and disease-related processes routinely reach 10-15 percent. These challenges include factors such as early sprouting, as well as slow wound-healing of potato tubers inadvertently damaged during the operational process.
Have you opened your home pantry and found potatoes sprouting? Immediately after harvest and for an indeterminate period thereafter, potato tubers are physiologically dormant and will not sprout even when they are placed in growth promoting conditions. The length of tuber dormancy period is determined by the genetics of the potato cultivar, and environmental conditions during the crop production and post-harvest storage—including temperature, humidity, light, and air composition. Premature sprouting or incomplete wound-healing adversely affects potato processing quality and nutritional value, resulting in lower producer prices or even complete market rejection by the industry and fresh market.
Munevver Dogramaci, a research plant physiologist and lead scientist of the Potato Research Program at the Edward T. Schafer Agricultural Research Center in Fargo, North Dakota, and Darrin Haagenson research plant physiologist at the Potato Research Worksite in East Grand Forks, Minnesota, collaborate with growers and universities to address these post-harvest physiological challenges, as well as to evaluate advanced potato breeding material for postharvest storage, food quality, and safety characteristics.
“Currently, there is no method that is 100 percent efficient to control the physical deterioration of the potato tubers during storage,” said Dogramaci. “Potato tubers are at their peak nutritional quality during harvest, but it is essential to store them under specific conditions to maintain this quality.”
A better understanding of physiological processes will help scientists improve post-harvest storage methods, preserving nutritional value, processing quality, and the marketability of potatoes.
Dogramaci also noted that unintended wounding of tubers, like cuts and bruises, can also occur during harvest and post-harvest operations. “This results in rapid quality loss that impacts the tuber’s texture, ability to retain water, and an increase in its susceptibility to diseases during storage,” Dogramaci explained.
Paul J. Collins, a research geneticist for the ARS Eastern potato breeding program based in Orono and Presque Isle, Maine, is working to develop new varieties for chip processing and table markets with improved agronomic attributes, disease resistance, climate resiliency, and quality traits. Successful varieties developed by this program include Atlantic, a variety that is widely grown across the U.S. for potato chips and is within the top ten most popular potato varieties grown in the nation.
“Potato breeding seeks to identify new potato varieties that can provide benefits throughout the value chain,” said Collins. “Farmers can benefit from disease resistance traits, resilience to climate variability, and improved yields. Processors and retailers are interested in maintaining quality and uniformity. Consumers are driven by improved nutrition and flavor. Within the breeding program, we see huge variability for all of these traits. The challenge and fun of potato breeding is finding a new variety which makes everyone in the value chain happy.”
Want to learn more? Watch the latest episode of “Cooking with Science“! USDA-ARS scientists share exciting facts about their work while Chef Mark Mills demonstrates how to incorporate potatoes into safe and nutritious recipes!
The Agricultural Research Service is the U.S. Department of Agriculture’s chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in U.S. agricultural research results in $20 of economic impact.
The U.S. Department of Agriculture (USDA) has announced it intends to renew the charter of the Fruit and Vegetable Industry Advisory Committee (FVIAC).
USDA is set to renew the committee’s charter for two years as required by the Federal Advisory Committee Act. The current charter expires on May 23, 2024. USDA invites interested persons to submit comments on this notice. Comments are due by 11:59 p.m. ET on May 1, 2024, through regulations.gov: Document # AMS-SC-24-0006.
Established in 2001, the FVIAC is administered by the USDA Agricultural Marketing Service (AMS). Committee members represent the entire spectrum of the fruit and vegetable industry including shippers, wholesalers, brokers, retailers, processors, fresh cut processors, foodservice suppliers, state agencies, state departments of agriculture and trade associations. The FVIAC meets in person at least twice a year to develop recommendations on issues affecting the U.S. produce industry.
This notice was published in the Federal Register on March 26, 2024. Information about the committee is available on the AMS Fruit and Vegetable Industry Advisory Committee webpage.
AMS policy is that diversity of the board should reflect the diversity of its industries in terms of the experience of members, methods of production and distribution, marketing strategies, and other distinguishing factors, including but not limited individuals from historically underserved communities, that will bring different perspectives and ideas to the table. Throughout the full nomination process, the industry must conduct extensive outreach, paying particular attention to reaching underserved communities, and consider the diversity of the population served and the knowledge, skills, and abilities of the members to serve a diverse population.
Navigating the consumer path to purchase can be complex, influenced by a countless factors. A new 
