Field Crops

UC Davis Releases 5 Strawberry Varieties Resistant to Deadly Fungal Disease

By Emily C. Dooley

The University of California, Davis, is releasing five new strawberry varieties that are resistant to the soilborne disease Fusarium wilt, have high yields and improved fruit quality.

UC Eclipse, UC Golden Gate, UC Keystone, UC Monarch and UC Surfline will be available for sale to California nurseries from Foundation Plant Services in April.

Roughly 88 percent of strawberries grown in the nation come from California. Fusarium wilt is one of the most common reasons for crop loss and death and yet 55 to 59 precent of cultivars planted in the state since 2014 have not been resistant, according to UC Davis research.

This is the first release from the UC Davis Strawberry Breeding Program where all the cultivars have Fusarium wilt resistance. They are meant to replace susceptible plants on the market such as Monterey, UCD Royal Royce and UCD Valiant.

Monarch was also developed specifically as a prototype for mechanical harvesting – another first out of the breeding program, which dates to the 1930s and has released 72 patented cultivars over the decades.

“These provide the same yield or better and they are Fusarium resistant,” said Steve Knapp, a Distinguished Professor in the Department of Plant Sciences and director of the UC Davis Strawberry Breeding Program. “They have a better collection of traits. They’re superior.”

Dangerous pathogen

Fusarium wilt didn’t present much of a danger to strawberry crops until after the fumigant methyl bromide was phased out of use in the United States in 2005. But the pathogen had always been in the soil, and cases of wilt appeared a year later and increased over time, leading to concerns that a Fusarium wilt pandemic could destroy the crop in California.

“The disease has taken off fast and we need to react quickly to address the need,” said Glenn Cole, a breeder and field manager with the Strawberry Breeding Program.

Knapp said the program tries to “encourage people to consider things like disease resistance” and routinely invites growers and other experts to events showcasing research breakthroughs and improved cultivars.

Varieties for the seasons

The new strawberry varieties each have improved flavor and characteristics that allow for near year-round growing around California, where about 1.8 billion pounds of the fruit are harvested each year. Some of the cultivars are adapted for production in the southern part of the state while others do well under the long daylight hours of summer along the coast.

Eclipse, a “summer plant” cultivar, has the potential to increase grower profitability as it produces in the fall and winter, and yields during research testing were 54 percent higher than similar cultivars. “We expect this cultivar to have wide commercial appeal,” Knapp said. “Eclipse is going to eclipse them all.”

Golden Gate and Keystone are “day neutral.” Those type of cultivars grow throughout the summer on about 60 percent of strawberry farming acres in the state. The “short-day” plants Surfline and Monarch are resistant to Verticillium wilt and Phytophthora crown rot.

Surfline and Eclipse are firmer and promise longer shelf lives. Monarch provides growers with improved fruit qualities relative to other mass-produced cultivars and has characteristics needed for advances in mechanical harvesting, Knapp said.

Genetic tools

Breeding program experts have long been researching ways to improve strawberry cultivars so the crop can withstand pests, disease and other stressors. To find plants that had Fusarium wilt resistance, they obtained the DNA of thousands of plants in field studies. The scientists also developed genetic tools to screen the plants and identify the genes that have resistance to the Fusarium pathogen.

Knowing that information allowed the team to breed resistance into and develop new cultivars, at a faster rate than previous efforts. “These tools have allowed us to sweep out the susceptibility and bring in resistance,” Knapp said.

2023-04-27T08:27:32-07:00April 27th, 2023|

California Strawberry Commission Statement on Pajaro and Salinas River Flooding

California Strawberry Commission President Rick Tomlinson released the following statement regarding the flooding occurring in the Pajaro community and along the Salinas River.

 

“This week’s flooding events along the Pajaro and Salinas Rivers have been devastating for those communities. Preliminary assessments estimate hundreds of millions in losses and thousands of people displaced in the town of Pajaro. The entire California strawberry industry would like to thank the first responders, aid organizations and volunteers who have helped begin the long recovery process.

 

We are thankful that the Pajaro River levee breach is being repaired. Stopping the river from flowing into the community is the first priority. This is a good start toward a safer place to live, raise a family, and work.

 

The foreseeable future will be challenging. Families will work to restore their homes, their jobs, and many other aspects of their lives.

 

Farms face a massive cleanup. As soon as the cleanup is complete, farmers will begin the process of preparing the fields and starting over.

 

For the farms that were flooded, this catastrophe hit at the worst possible time. Farmers had borrowed money to prepare the fields and were weeks away from beginning to harvest. Disaster relief and emergency financial assistance will be critical for both the residential community and the farming operations.

 

California strawberry operations, most of which are multi-generational and family-owned, will remain vital to the damaged areas during the recovery and well beyond.

 

California’s 400 family strawberry operations create 70,000 jobs in the state and invest 97 cents of every dollar back into the community. That commitment will only grow as the damaged area recovers. Despite the challenges, there will be increased shipments of California strawberries from Oxnard and Santa Maria to stores across the country to keep up with high demand.

 

Times are tough, but the town of Pajaro, the surrounding communities and the strawberry farming families are more resilient than ever, and we will work together to recover,” said Rick Tomlinson, California Strawberry Commission President.

 

There are photos available for media use. Plese click here and credit California Strawberry Commission.

2023-03-17T16:16:53-07:00March 17th, 2023|

New UCCE Advisors Bring Fresh Ideas to Protect Lettuce From INSV, Pythium Wilt

By Mike Hsu, UCANR

Salinas Valley lettuce growers lost about $150 million in 2022 due to diseases

A stormy winter could portend another devastating year for the lettuce industry in the Salinas Valley, which saw approximately $150 million in lost gross revenue in 2022 due to INSV (impatiens necrotic spot virus) and associated diseases. Recent drenching rains might mean more weeds – overwintering “reservoirs” for the tiny insect, the Western flower thrips, that carries INSV.

Or the extreme precipitation could benefit growers, as thrips in the soil – during their intermediate stage of development – might be drowned in the waterlogged fields.

As with so many aspects of the INSV crisis, the ultimate effects of flooded fields on thrips populations remain unknown.

“We don’t know if thrips are just so persistent and so stable in that pupal stage that maybe they will emerge unaffected,” said Kirsten Pearsons, University of California Cooperative Extension integrated pest management farm advisor for Santa Cruz, Monterey and San Benito counties. “There’s just so much about their biology and ecology in the Salinas Valley that we just don’t know.”

The mystery of thrips, INSV and soilborne diseases (namely Pythium wilt) is why UC Agriculture and Natural Resources assigned Pearsons to the area last November and hired Yu-Chen Wang in October as UCCE plant pathology advisor for the three counties.

“They’re stepping in at a critical moment,” said Richard Smith, the region’s UCCE vegetable crop production and weed science advisor who retired in January after a 37-year career. “They’ve gotten grants funded already – and that’s just incredible. They’re hitting the ground running.”

Experienced in disease diagnosis and collaboration with growers and industry partners, Wang said her pathology background – paired with Pearsons’ entomology expertise – will be crucial in addressing INSV and other diseases.

“It is important for Kirsten and me to work together and provide different insights for the vector and the pathogen, respectively,” Wang said.

‘It’s going to take everything to get a crop’

One priority is untangling the dynamics of INSV and Pythium wilt co-occurrence – the subject of ongoing research by JP Dundore-Arias, a plant pathologist at California State University, Monterey Bay. While the vegetables may tolerate one disease or the other, their one-two punch often deals the lethal blow. 

“The challenge is – which is why it’s great to have Yu-Chen and Kirsten – is that we have so many problems now, whether it’s Fusarium (wilt), or Verticillium (wilt), or Pythium, or INSV,” said Mark Mason, pest control adviser for Nature’s Reward, which primarily grows lettuces on 5,000 acres across the Salinas Valley.

Mason said that co-infections on his crops (sometimes with three or four diagnosed diseases) make it difficult to assign monetary damages to a specific pathogen, but he noted he has seen fields with “100% loss.” According to the Grower-Shipper Association of Central California, about 11,500 acres were deemed not harvestable in 2022, representing 12% of lettuce industry acreage.

Given the gravity and complexity of the disease dilemma, Pearsons said she has been fielding calls from growers seeking new and better solutions – ways to improve existing tools, techniques borrowed from other crop systems, and additional biological or chemical means of control.

And although there are a couple of pesticides that manage the disease-carrying thrips reasonably well, growers and researchers are worried about their diminishing efficacy due to overuse. Plus, they only constitute a short-term fix.

“Managing the thrips will only reduce the amount of INSV that can get transmitted,” Pearsons explained. “You can kill 99.9% of the thrips, but you get one thrips that has INSV that enters a field, and now you have an infected lettuce plant. All of the thrips are going to come and they can spread it from there; pesticide slows things down, but it’s not going to eliminate it.”

Finding disease-tolerant lettuce cultivars is a more sustainable approach. Trials conducted last year by Smith, Wang and others identified several varieties that appeared to hold up well to Pythium and INSV. While additional research could maximize their potential benefit, Wang said even the hardier cultivars will lose their resistance over time, and a multi-layered INSV strategy with “integrated management tools” is crucial.

“We realized, when this thing started happening, that we cannot spray our way out of this problem,” Mason said. “We need varieties; we need management practices; we need pesticides…it just seems like it’s going to take everything to get a crop.”

Weeds key to disease control

An all-hands-on-deck approach helped control thrips-harboring weeds last winter. With fields drying out from January storms, Smith said communities must get back to weed management – with a focus on prominent weed hosts for INSV and neglected areas adjacent to farms. Hotspots of infection last year were traced to industrial lots that were overlooked during the weeding process.

“People can’t lose sight of the fact that we still need to be controlling the weeds in key areas, because that’s the reservoir of the virus during the winter,” Smith said. “We have to stay on task with that.”

Yet despite the diligent weed abatement, crop damage from INSV and Pythium was widespread in 2022, and Smith said it’s “very possible” that high heat during the summer was a contributing factor to especially prevalent disease in fall. Thrips populations tend to thrive in warmer weather, Smith said, but much more research needs to be done to understand the basic biology of the insect, including how they acquire the virus and how they spread it.

High hopes for future

Pearsons cited the work of Daniel Hasegawa, a research entomologist with the U.S. Department of Agriculture, who leads teams in monitoring thrips populations in several locations across the Salinas Valley. Currently the counting of thrips on sticky card traps is done manually, but Pearsons and Mason mentioned the possibility of using AI and machine learning to expedite that process.

Mason said that the grower community is excited about the new technologies and ideas that Pearsons and Wang are bringing to the region. As a participant in the search for candidates to fill the advisor positions, Mason said “they were, in my opinion, by far the best fit for what we were looking for.”

“I hope they stay here for 30 years,” he added.

The new advisors both noted the palpable energy and cooperative spirit in the Salinas Valley to proactively meet the challenge.

“Looking to the past, there have been other outbreaks and diseases that they’ve managed to overcome,” Pearsons said. “These farmers are resilient and creative and I fully believe that lettuce will still be growing here for years to come – it might look a little different, and it might take a little bit of a painful period to get to that point, but I think that we’re going to be able to come up with some solutions.”

And while there are concerns that some lettuce growers might decide to leave the region, Wang said she also believes in the industry’s strong roots and rich history.

“Salinas Valley has had a beautiful climate for lettuce for so many years; there are some undeniable advantages here,” she said. “This is still the best place in the United States – and maybe the world – to grow lettuce.”

2023-02-03T16:01:34-08:00February 3rd, 2023|

Pitahaya/dragon fruit growers gather to learn from UCCE research and each other

By Saoimanu Sope, UCANR

Once you know what a dragon fruit looks like, you will never forget it. The bright red, sometimes yellow or purple, scaly skin makes for a dramatic appearance. One that will surely leave an impression. The flesh ranges from white to a deep pink and the flavor is often described as having hints of kiwi, watermelon, or pear.

Since 2007, the Pitahaya/Dragon Fruit Production Tour, has united dragon fruit growers of all levels and backgrounds. After a two-year hiatus due to the pandemic, registration for the 2022 tour filled up in less than 24 hours.

A group of 60 participants gathered Sept. 8 at the Wallace Ranch Dragon Fruit Farm in Bonsall to learn the latest research on growing the drought-tolerant specialty crop. Ramiro Lobo, a small farms and agricultural economics advisor for UC Cooperative Extension in San Diego County, introduced dragon fruit growers and other UC scientists.

“I can’t remember a year where this event was not sold out. So, the need and demand is there,” said Eyal Givon, a long-time participant and dragon fruit grower.

The tour not only demonstrates how to grow the fruit, but it also grants participants access to plant material for varieties that are unavailable elsewhere.

“We have given out about 50,000 cuttings through our festival and some varieties were unique to us because we introduced them to the U.S.,” said Lobo.

During their time at Wallace Ranch, participants heard from the farm’s owner, Neva Day, regarding the growing practices that have shaped her success today. Day has been growing organic dragon fruit since 2013 and has well over 5,000 plants on the ground and more than 20 varieties.

Eric Middleton, UCCE integrated pest management area advisor for San Diego County, talked about managing insects and pests that growers are likely to encounter such as Argentine ants.

According to Middleton, Pecan Sandies are a balanced source of fat, protein, and sugar, making them excellent bait for the sugar-loving insects.

Participants eventually made their way to Dragon Delights Farm located in Ramona. Kevin Brixey, the farm’s owner, has been growing organic dragon fruit for six years.

Although Brixey was hosting this year’s tour participants, he used to be one of them.

“I attended the Pitahaya Festival in 2014 and that’s where I realized dragon fruit was something I could grow. There was a lot of good information being shared and a connection to other growers, so it was a major steppingstone for me,” he says.

Unlike traditional dragon fruit growers, Brixey uses shade to grow his dragon fruit after learning about the method from another grower.

“I was impressed. I liked how the fruit performed under shade and now I use it as a management tool,” Brixey explained. In Inland Valleys, shade can shield fruit from intense sunlight and protect them from unwanted guests that eat the fruit, such as birds.

At the Farm Bureau of San Diego County offices, participants learned about the history of dragon fruit growing in California, food safety, pest management, best production practices and much more.

The presenters included experts like Paul Erickson from Rare Dragon Fruit, Lobo, Middleton, Johanna del Castillo from UC Davis Department of Plant Pathology and Ariana Reyes, a community education specialist from UCCE San Diego.

When reflecting on his time participating in the production tour, Givon, who has been growing dragon fruit for about 20 years and manages a 20-acre farm in Moorpark, said he enjoys reconnecting with other growers the most.

“What others are doing, might be better than what I’m doing,” Givon said. “Or what I’m doing, could be better than what someone else is doing. This time together is good for us to learn from each other.”

Lobo agreed with Givon and added, “I hope that these tours become self-sustained, and that we go back to a research field day at Southcoast REC with regional tours in San Diego and Ventura as we did before, or any other counties.”

The Pitahaya/Dragon Fruit Production Tour is an annual event hosted by UCCE San Diego. To learn more about UCCE San Diego events, visit https://cesandiego.ucanr.edu

2022-10-25T08:08:03-07:00October 25th, 2022|

Decertification Action

If an LGMA member is found to be out of compliance with the food safety standards the program can decertify the company. 

LGMA members work to provide the safest leafy greens on the market through a rigorous set of food safety practices that are verified by audits conducted by the California Department of Food and Agriculture. However, if a company is found to be out of compliance with the food safety standards the program can decertify a member. Although this happens rarely, California LGMA and the California Department of Food and Agriculture recently decertified a member company.

The LGMA audit verifies compliance with over 500 food safety checkpoints. LGMA members are required to be 100% in compliance, which means that if an audit identifies a non-conformity the member must submit corrective actions to the LGMA Compliance Officer. If a company fails to demonstrate full compliance, they are subject to decertification.

Decertification means that a company cannot present itself as a certified LGMA member, nor use the LGMA Service Mark. Government agencies and produce buyers rely on LGMA certification for supplier verification. Loss of certification potentially means a loss of sales, including product being turned away from international borders. An up-to-date list of LGMA members and their certification status is available on our website: https://lgma.ca.gov/certified-members

2022-10-19T09:02:16-07:00October 19th, 2022|

UC Study Breaks Down Costs of Growing Organic Strawberries

By Pam Kan-Rice, UCANR

Thinking about commercially growing organic strawberries on the Central Coast?

To help prospective and current growers evaluate financial feasibility, the University of California has estimated costs to produce and harvest organic strawberries for fresh market in Santa Cruz, San Benito and Monterey counties.

“This revise of the last cost-of-production study incorporates the newest in labor costs along with updates on cultural techniques,” said study co-author Mark Bolda, UC Cooperative Extension strawberries and caneberries advisor in Santa Cruz, San Benito and Monterey counties.

The new study, “Sample Costs to Produce and Harvest Organic Strawberries in the Central Coast Region-2022,” has been released by UC Agriculture and Natural Resources and UC Davis Department of Agricultural and Resource Economics.

The analysis is based on a hypothetical well-managed organic strawberry farm using practices common to the region, but the costs, materials and practices shown in this study will not apply to all farms. Growers, UC Cooperative Extension farm advisors and specialists, pest control advisers and others provided input and reviewed the methods and findings of the study.

“Current growers can use it as a baseline to compare with their own cost and returns estimates to make sure they have an accurate picture of the profitability of their organic strawberry enterprise,” said co-author Brittney Goodrich, UC Cooperative Extension agricultural economics specialist. “Many agricultural lenders use these studies as a baseline to determine whether to approve operating or investment loan requests from current and potential strawberry growers.”

The researchers assume a farm operation size of 30 contiguous acres of rented land, with strawberries are planted on 27 acres. The study includes a list of suitable strawberry varieties for the region, but no specific variety is used in the study. The crop is harvested by hand and packed into trays containing eight 1-pound clamshells from April through early October, with peak harvest in June through August.

The authors describe the assumptions used to identify current costs for production material inputs and cash and non-cash overhead. Ranging analysis tables show net profits over a range of prices and yields. Other tables show the monthly cash costs, the costs and returns per acre, hourly equipment costs, and the whole farm annual equipment, investment and business overhead costs.

The study’s expanded section on labor includes information on California’s new minimum wage and overtime laws.

“It’s reached a wider audience this time through presentations of the material to students at Cal Poly [San Luis Obispo] and also a group of USDA officials at the California Strawberry Commission,” said Bolda.

“All of this just underlines the value of these studies to California growers and others working in agriculture,” Bolda said.

Free copies of this study and other sample cost of production studies for many commodities are available. To download the cost studies, visit the UC Davis Department of Agricultural and Resource Economics website at https://coststudies.ucdavis.edu.

This cost and returns study was funded by the UC Davis Department of Agricultural and Resource Economics.

For additional information or an explanation of the calculations used in the studies, contact Jeremy Murdock, UC Davis Department of Agricultural and Resource Economics, at jmmurdock@ucdavis.edu or UC Cooperative Extension’s Bolda at (831) 763-8025.

2022-08-26T08:15:47-07:00August 26th, 2022|

Study: New Fumigation Stategy

New Fumigation Techniques for Soilborne Diseases

By Tim Hammerich with the Ag Information Network

Protecting fruit from soilborne pathogens is a big concern for strawberry growers. Researchers at the University of California Ag and Natural Resources are looking to see if a drip application of fungicides might be effective, noted UC Cooperative Extension advisor in entomology and biologicals, Surendra Dara.

“This particular study was based on a request from FMC. They wanted to evaluate if drip application of some fungicides could be supplemental to whatever the growers are currently following to control soilborne diseases. And they also wanted to see if it has any impact on improving the crop health, and potentially other diseases,” said Dara.

Dara noted the results from the first trial were positive, but he didn’t see enough incidence of soilborne disease in the control group to be sure. He’s optimistic though, given drip application of fungicides has been effective on other plant pathogens.

“They do apply fungicides to drip, but not necessarily for soilborne diseases. The management practices are usually obtaining clean transplants and fumigating or crop rotation. These are the typical management recommendations for soil-borne diseases,” explained Dara.

Dara hopes to continue to study the potential for this management practice.

2021-07-23T21:22:40-07:00July 22nd, 2021|

Naturipe Farms Produces Berries for Global Consumers

Naturipe Farms is Leading Growers of Blueberries in the World

By Tim Hammerich, with the Ag Information Network of the West 

 

Naturipe Farms is a brand most Americans have seen in the supermarket. What many may not realize is that the company is actually owned by growers. California Ag Today’s Patrick Cavanaugh recently spoke to Jill Overdorf, who is Naturipe’s Director of Business Development for Food Service & their Corporate Chef.

“Producing fresh berries since 1917, Naturipe Farms is unique to the produce industry with a partnership between four highly esteemed berry growers: Naturipe Berry Growers, MBG Marketing(Michigan Blueberry Growers), Hortifrut, and Munger Companies,” said Orverdorf.

Overdorff said Naturipe is the leading grower of blueberries in the world, second in strawberries, and also produce raspberries, blackberries, avocados, and cranberries.

“Our strawberry growers had a very challenging year, but they developed some great crops,” noted Overdorff. “We also have a good breeding program. Our blueberry growers, the Mungers, are the largest growers of blueberries in California. They had a phenomenal year, and they are branching out and are enormously innovative. They’re leading our value added program with their proprietary wash process, which enables 21 days on a fresh blueberry shelf life for a snack product,” explained Overdorff.

“Our blackberries and raspberries, we have a number of proprietary varieties, including the Centennial Raspberry and the Madeline Blackberry, both flavorful and non traditional berries because of their load seed count and they’re delicious flavor,” she said.

2020-02-01T08:07:49-08:00January 31st, 2020|

Produce Passes All Residue Testing in 2017

FDA Produce Residue Sampling “Once Again” Verifies Safety

Last week the Federal Food and Drug Administration (FDA) released its 2017 pesticide residue sampling data results. FDA concluded: “The latest set of results demonstrate once again that the majority of the foods we test are well below the federal limits set by the Environmental Protection Agency.”

Note the term “once again” in FDA’s statement. They used it because government residue sampling data year after year reaffirms the safety of our food and the exceptionally high level of compliance among farmers with laws and regulations covering the use of organic and conventional pesticides.

Let’s get a little technical for a moment and focus on how FDA residue sampling is protective of consumers. FDA employs a three-fold strategy to enforce the Environmental Protection Agency’s (EPA) tolerances or safety standards for pesticide residues.
If you haven’t heard – September is National Fruit and Vegetable month. Yes, it is time to celebrate the only food group health experts and nutritionists agree we should all eat more of every day for better health and a longer life.
While decades of studies have shown the nutritional benefits of fruits and vegetables are overwhelming and significant, the safety of both organic and conventional produce is also impressive. Government sampling data shows an over 99% compliance rate among farmers with the laws and regulations required for pesticide applications on organic and conventional fruit and vegetable crops. This led the United States Department of Agriculture to state that: “The U.S. food supply is among the safest in the world.”

Many health organizations are promoting National Fruit and Vegetable month to remind consumers about the importance of increasing consumption – only one in 10 of us eat enough of these nutrient-packed foods each day.

However, studies show a growing barrier to consumption is fear-based messaging which inaccurately calls into question the safety of the more affordable and accessible fruits and veggies. This messaging is predominantly carried by the same activist groups year after year despite studies which show that “prescriptions” for fruits and veggies could reduce health care costs by $40 billion annually. Or that 20,000 cancer cases could be prevented each year.

2019-09-23T15:06:22-07:00September 23rd, 2019|

Even Organic Production of Strawberries Not Sustainable

Data Shows Even Organic Production Uses Resources

By Jessica Theisman, Associate Editor

Is growing strawberries organically sustainable? That’s something that Surendra Dara is trying to find out. Dara is a UC Cooperative Extension Advisor in Entomology and Biologicals. He is based in San Luis Obispo County as well as Santa Barbara County. Dara met with California Ag Today recently and let us in on his research and some of his findings.

“I have not come across a mainstream grower that has told me that organic is sustainable,” Dara said.

After pulling in data and understanding the inputs, Dara is asking if there is anybody out there that has a different opinion.

“When we are talking about sustainability, we are looking only in terms of non-chemical being the sustainable, ecological practice,” he said.

There are such things as organic pesticides that harm natural enemies.

“Some of the organic ones can be as bad as some of the chemicals,” Dara said.

Data is showing that growing strawberries organically has not been sustainable economically. In terms of the carbon footprint and the bigger picture, “even organic production is not sustainable with the resources because certainly some resources are being used up,” Dara said.

2021-05-12T11:05:02-07:00July 10th, 2019|
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