Disease

Potato Wart Panic: U.S. Growers Demand Ban on Canadian Imports

Tue, 19 May 2026 12:11:46 GMT

Warning that American agriculture faces a potentially catastrophic economic threat, the National Potato Council is urging the immediate reinstatement of a federal ban on Canadian fresh potato imports from Prince Edward Island following a newly confirmed detection of potato wart — a highly destructive fungal disease — in a previously unregulated field.

On May 18, NPC and 13 U.S. state potato organizations sent a letter to USDA Undersecretary for Marketing and Regulatory Services Dudley Hoskins stressing that this new detection exposes severe vulnerabilities in current border protections and proves that the disease spreads beyond known containment zones.

“The threat is to the entirety of the industry, and we are desperately trying to avoid potato wart,” Kam Quarles, CEO of NPC, tells The Packer. “It is an incredibly insidious disease. It will exist in a dormant fashion in the soil for decades, and the moment it comes in contact with host material, it’s off and running again. So, the solution to potato wart is, don’t get it. That is your first and best line of defense.”

The USDA Animal and Plant Health Inspection Service currently classifies potato wart as a select agent — one of only seven high-consequence plant pathogens listed as severe threats to domestic agriculture. According to data from the Canadian Food Inspection Agency, the fungus can survive in soil for more than 40 years, and no chemical treatments exist to control or eradicate it.

NPC insists the introduction of potato wart in the U.S. would have devastating economic consequences for domestic family farms, as the U.S. potato industry generates more than $100 billion in annual economic activity and supports over 714,000 jobs. A domestic outbreak would prompt an immediate loss of access to all international fresh potato markets, costing American growers over $225 million in direct annual export losses and billions more in indirect economic damage.

“If — and this is a doomsday scenario — if potato wart got into a production area in the U.S., we are going to lose on an immediate basis, and it doesn’t matter where it is in our country, we will immediately lose our export markets overnight,” Quarles says. “The impact of that, both the direct and indirect impact, could be catastrophic for our industry. So, we are approaching this with a huge amount of sensitivity and an abundance of caution. We do not want this disease in the United States.”

Potato Wart Politicized

Quarles says while NPC “sympathizes greatly with Prince Edward Island,” there’s been a history of permissive policy around potato wart.

When a major potato wart outbreak hit the island in 2021, the U.S. government immediately halted all fresh potato imports from the Canadian province to prevent the disease from spreading. But due to the economic toll on the region, NPC says the decision triggered significant political pushback from PEI leaders, prompting the Biden administration to treat the trade dispute as a political irritant rather than a biological threat. The U.S. reopened the border to PEI fresh potato imports in May 2022.

“We have, from the beginning, treated this as a phytosanitary matter,” says Quarles. “The disease does not care about political leaders. It doesn’t care about your talking points. The disease wants to get out. It wants to move, and if you’re not taking concrete steps to keep that disease under control — and the most important one is — if you are not surveying your fields comprehensively and constantly, you have a big problem, because you don’t know where this thing is.”

Despite an October 2022 APHIS pathway analysis warning that “the full extent of the potato wart infestation in PEI is still unknown but is likely to be larger than currently reported,” subsequent mitigation protocols remained largely unchanged, says NPC.

NPC previously expressed concerns over the effectiveness of Canada’s 2024 National Potato Wart Survey. The industry noted that it evaluated a very small sample size of only 2,200 fields and entirely skipped testing in fields with previous detections.

“It’s sort of surprising that a national survey picked it up, because it’s really like a 30,000-foot look at potato production across all of Canada, but it found it in an entirely new field outside of all of their regulated areas, which is where they thought the disease was confined to,” says Quarles. “But it jumped it. It’s out. It’s kind of like a fire jumping a fire break and now that’s triggered 1,000 new acres — but the field itself and then surrounding fields go under regulation to try to keep it from moving.”

Demanding Decisive Action

Potato wart can spread by infected tubers, infested soil attached to potato tubers, machinery, implements used in infested potato fields, footwear and manure from animals that have fed on infested tubers. Symptoms above ground are rare, but plants may show reduced vigor and leaf and shoot malformations. The disease is usually detected during harvest, when the infected potatoes exhibit abnormal wartlike growths.

For years, NPC and the U.S. potato industry urged APHIS to use its authority to implement common-sense risk-mitigation measures, says NPC.

The industry previously recommended:

Restricting bulk potato shipments into the U.S.
Limiting large retail shipments and mandating strict traceback labeling on consumer packages.
Imposing stringent controls on agricultural waste generated by processing and bulk handling facilities.

Federal authorities have not yet acted on any of these recommendations, says NPC. The group points out that if the roles were reversed, Canada would never tolerate such a permissive standard from the U.S. regarding a threat of this magnitude.

“Given the disease progression on PEI, coupled with the lack of enhanced phytosanitary actions to date, we strongly urge you to suspend PEI’s ability to ship fresh potatoes into the United States,” the letter concludes.

Quarles highlights a disparity between the rigorous protocols historically imposed on the U.S. and Canada’s current management of the potato wart outbreak on Prince Edward Island. When Idaho faced a nematode outbreak, Canada mandated an aggressive, long-term testing regimen that continues to this day — far surpassing the level of scrutiny and testing currently implemented by PEI for potato wart, he says.

“We have had to be very vocal with the Canadian government and with the public about the deficiencies in terms of their visibility on where this disease is,” says Quarles. “We have asked the Canadians to be really aggressive in terms of testing and their mitigation strategies.

“There hasn’t been really any movement on the on the USDA side,” he continues. “The only thing that’s blocked is seed potatoes coming in, so Canada has updated their mitigation strategies for how they deal with wart in terms of what their process will be going forward. And the challenge with that is they had a new plan in place, it’s been implemented and the disease is still moving around.

“From the start, we’ve been saying this is a disease issue. Deal with the disease,” he says. “There’s been a lot of politics at play here, but the time for that is just flat out over.”

Enza Zaden, Pairwise on Mission to Feed the World Vegetables

Thu, 20 Nov 2025 18:19:05 GMT

Enza Zaden, a Netherlands-based vegetable breeding company that develops and supplies vegetable seeds for some 30 crops to growers worldwide, has entered a strategic agreement to license Pairwise’s Fulcrum Platform, a suite of precision plant breeding tools.

“At Enza Zaden, our mission is to grant people everywhere access to healthy vegetables by developing high-quality varieties and seeds,” says Jaap Mazereeuw, CEO of Enza Zaden. “This collaboration reflects our commitment to breakthrough plant science and responsible innovation to benefit growers, consumers and the environment. Pairwise’s Fulcrum Platform equips us with advanced tools for research, strengthening our ongoing focus on sustainability and creating value for our customers.”

Co-founded by the inventors of CRISPR, Pairwise’s Fulcrum Platform aims to accelerate the development of climate-resilient, nutritious and sustainable crops. By integrating advanced gene-editing tools with its intellectual property portfolio, Pairwise says the platform enables accelerated agricultural innovation worldwide.

“Enza Zaden has a long tradition of developing innovative vegetable varieties. We’re proud to support them in accelerating the natural potential of crops with cutting-edge tools,” says Tom Adams, CEO of Pairwise. “Gene editing is a precise, modern breeding method that complements traditional approaches, enabling breeders to achieve results faster while addressing key challenges like sustainability and disease resistance. Gene editing represents a vital tool for advancing resilient, climate-smart crops that align with sustainable agriculture goals.”

To learn more about the partnership, The Packer connected with Xana Verweij, global biotech director for Enza Zaden.

What are the most pressing challenges vegetable growers face today that gene editing can solve, and how will Enza Zaden and Pairwise joining forces help to expedite these solutions?

Verweij: The world’s population is growing rapidly, and climate change is intensifying the challenges faced by vegetable growers. At Enza Zaden, we contribute to the global availability of healthy food and a sustainable future by developing vegetable varieties that, for example, are resistant to diseases and better able to withstand extreme weather conditions.

The agreement with Pairwise is focused on research and innovation in plant science, supporting Enza Zaden’s mission to breed vegetables that help feed the world. Gene-editing technology will be used to enhance our research programs. The goal is to accelerate the development of improved vegetable varieties that meet the evolving needs of growers, retailers, and consumers.

Are there certain types of vegetables on which Enza Zaden will be focused using the Pairwise platform breeding tools?

The GE technology and IP licensed from Pairwise will be used to enhance Enza Zaden’s research programs. The goal is to accelerate the development of vegetable varieties that meet the evolving needs of growers, retailers and consumers. At this moment all use is focused on research; any future commercial use will be considered in line with regulatory and market developments and Enza Zaden’s strategy.

What are some of Enza Zaden’s past vegetable seed innovation success stories, and what impact have they had on the fresh produce industry?

Enza Zaden has developed tomato seeds with resistance to Tomato Brown Rugose Fruit Virus (ToBRFV), a major global threat to tomato production. These resistant varieties help growers maintain yields and fruit quality, reduce losses and ensure a reliable supply for retailers and consumers.

Each year, Enza Zaden introduces approximately 100 new varieties designed to help growers worldwide produce healthy, diverse and sustainable food. Do you expect the partnership with Pairwise will eventually result in the commercial launch of new vegetable seeds?

The agreement is focused on research use at this moment; there are no genome-edited varieties being introduced to the market as part of this agreement. Enza Zaden’s commitment to non-GMO commercial breeding remains unchanged. Possible commercial use will be communicated when relevant.

Growers Feel the Squeeze as County's Citrus Industry Drops

Fri, 13 Nov 2020 06:04:54 GMT

MERRITT ISLAND, Fla. (AP) — From a 2-acre plot on north Merritt Island, Steve Crisafulli looks at rows of orange trees, searching for a glimmer of hope for Brevard’s dying citrus industry.

Crisafulli — a Merritt Island resident whose last name has been synonymous with the citrus business for five generations — has given over this small grove on his family’s land for a U.S. Department of Agriculture experiment that he prays will unlock the secret of a more disease-resistant orange tree.

The test grove contains about five different varieties of citrus trees planted in combination with about 10 different root stocks. The goal is to determine which combinations work best.

The Crisafullis view the USDA project as perhaps the last-ditch effort to stem the painful, long-term downturn of the citrus industry. Citrus production in Florida has dropped 59 percent since the 2008-09 season.

Production plunged even more in Brevard County, by 87 percent. And, recently, two of the area’s last traditional citrus retailers — Harvey’s Groves stores in Rockledge and West Melbourne and the Policicchio Groves retail store on north Merritt Island — announced they not open their stands for the 2017-18 season. The companies will keep operating their mail order businesses.

For some, the closing of these iconic roadside attractions is a bittersweet reminder of an older Brevard, a sleepier community before the rumble of rockets, when citrus was king and a muck-free, crystal-clear Indian River teemed with sea trout and manatees. Sorting warehouses dominated the landscape on U.S. 1, and trucks filled with pungent fruit plied the roads.

Now, some of those warehouses are crumbling derelicts, as diseases like canker and citrus greening — and hurricanes — have hit the industry hard. Many growers decided it was more lucrative to sell their groves to developers to transform them into residential subdivisions, rather than continue growing oranges or grapefruits.

And a looming question is where to buy the renowned orange and grapefruit juice that only comes from Indian River-grown fruit?

Indian River citrus has always been world-renowned for its quality and still is, albeit with a deeply declining production — if you can find it.

Even longtime local citrus growers like Crisafulli and Frank Sullivan of Cocoa say their families now buy their orange juice at the grocery store. But it’s not nearly the same as the fresh-squeezed juice.

“None of it really measures up,” Sullivan said.

Crisafulli agrees.

“Nothing is as good as the real thing,” he said with a grin.

Thinking about the citrus industry’s downturn, Crisafulli says: “I think it’s sad, because it’s an identity not just for Brevard, but the entire state.”

“Along the river, on both sides of the river, and certainly all of Merritt Island, was nothing but citrus groves,” Sullivan said. “There were 9,000 acres of citrus inside NASA,” referring to the sprawling federal reserve that is home to the Kennedy Space Center.

That land was “some of the best growing land in the state” for citrus, Sullivan said.

The downturn didn’t happen suddenly. Florida citrus production peaked in 1997-98, when 304.45 million boxes of oranges, grapefruits and other citrus were produced. By 2016-17, that figure dropped 74 percent to 78.13 million boxes. The latest projection for the current 2017-18 season puts expected production at 54.65 million boxes. Each box would weigh 85 to 95 pounds, depending on the type of fruit.

Sullivan, who is in the third-generation of his family in the citrus business, traces the local industry’s problems back even further — to the devastating freezes of the 1980s.

“That took a lot of citrus out. Then, there was the disease,” said Sullivan, who no longer grows citrus, but continues to operate the Sullivan Victory Groves citrus mail order business on U.S. 1 in Cocoa.

Sullivan and other citrus mail order businesses in the region coordinate their purchase of citrus for resale from a handful of remaining local growers, including one in Scottsmoor.

“It facilitates buying the best fruit” that’s available at any particular time, said Sullivan, who also is a former Canaveral Port Authority commissioner. “We go wherever we can get it.”

This is a peak season for the mail order business, as many people want fresh fruit ahead of the holidays.

Even with the thinning of the citrus industry in Florida, Doug Bournique, executive vice president of the Fort Pierce-based Indian River Citrus League, said he is hopeful growers in Brevard will make a resurgence in producing oranges and grapefruit on the Space Coast.

Calling the Crisafullis, Harveys and Sullivans “rock star” growers of Indian River fruit, Bournique believes researchers are very close — maybe within two years — of “cracking the code” when it comes to ending citrus greening — a disease, also known as “yellow dragon disease” — that severely damages and discolors the fruit and eventually kills the tree.

Once the code is cracked, Bournique believes citrus will stage a big comeback in Brevard and elsewhere in Florida.

It’s not just the fruit and juice that’s enticing growers, but the Indian River citrus byproducts that are finding their ways into soaps, shampoos, beer, spirits and many other areas. The products often carry on “Indian River” citrus on the label, and it’s an entirely new market to exploit that wasn’t available 20 years ago.

“It used to be growers would simply use it for livestock feed,” Bournique said. “The byproduct market that wasn’t there 20 years ago is there now.”

Sullivan thinks back to the time when Brevard County’s population was relatively small, but there were a dozen or more citrus packinghouses in the area.

“And it seemed like everybody who had 20 acres has a little fruit stand,” Sullivan said. “When U.S. 1 was the only route going from the north to Miami, everybody had a fruit stand.”

Sullivan said much of his family’s citrus acreage was on land that now is part of Kennedy Space Center.

Historically, Sullivan said, most of this region’s citrus has been used for juice, with much of the remaining fruit used for the holiday gift fruit business.

Referring to the industry’s decline, Sullivan said: “It’s discouraging, but we haven’t give up hope. New varieties are showing signs of resistance to diseases. Farmers are always optimistic. We just have to work a little harder doing what we do.”

“Obviously, it’s a very unfortunate time in the industry,” Crisafulli said.

While disease has played a role, so has the weather.

“Mother Nature has her time, and she’s had a say in where we are today,” Crisafulli said. “Whether it’s freeze, flood, drought, heat or cold, we’re also dealing with disease, and that’s a challenge that we’ll continue to have.”

Hurricane Irma, for example, impacted the industry in two ways when it passed through Florida in September, Crisafulli said. The high winds blew fruit off the trees prematurely, decreasing this year’s crop. But, more significantly, if an orange grove is flooded and water sits on a tree root for more than 36 to 48 hours, it can kill the trees for good, he said.

“The storms were the straw that broke the camel’s back” for the remaining retail stands, Crisafulli said. “It’s very unfortunate.”

The Crisafulli family now is using much of its former citrus land for other business interests, including residential development and as cattle grazing land.

Still, Crisafulli said, he and others in the industry are not ready to abandon the industry.

“Looking forward, looking to the future, we’re certainly not going to give up,” said Crisafulli, who is a former speaker of the Florida House of Representatives. “Farmers are a resilient breed. If it wasn’t for farmers, we’d be eating grass next to the cows. So it’s certainly a time where we have to pick up and look for the future and look for the opportunities that are before us.”

Crisafulli said his 2-acre site on north Merritt Island is part of a widespread efforts involving USDA and state researchers to develop new breeds, new varieties, new root stocks and new places to plant citrus throughout the state.

“I will certainly say that we’re not going to give up. There are opportunities for us,” Crisafulli said. “The sad thing is the mom-and-pop operations will have a harder time enduring this period. And you’re going to see the larger corporations are going to continue to move forward and try to find opportunities to grow in this industry. We’re certainly interested in the future of what citrus holds.”

For his business, part of that future could be an orange variety being called the “Crisafulli navel” that has been developed over the last several years.

Crisafulli said, while some of the issues may be unique to Florida citrus, the agriculture industry in general constantly has obstacles to overcome.

“Farmers have that, whether it’s citrus or corn or wheat or whatever it might be,” Crisafulli said. “There’s always going to be challenges. And we’re certainly going to fight to the end to try to make sure that we can preserve this great industry.”

Information from: Florida Today (Melbourne, Fla.), http://www.floridatoday.com

Florida Orange Crop Seen Plunging to 71-Year Low After Irma

Fri, 13 Nov 2020 06:04:46 GMT

(Bloomberg) -- Florida’s orange production will plunge 21 percent to a 71-year low after damage wrought by Hurricane Irma devastated the harvest, while output of cotton also suffered in storm-hit areas, government figures showed.

Orange growers in Florida, the largest U.S. producer, will harvest 54 million boxes in the 2017-18 marketing year, the least since 1947 -- an era when citrus irrigation was rare -- the U.S. Department of Agriculture said in a report Thursday. A survey of analysts conducted by Bloomberg indicated a crop of 58.2 million boxes. A box weighs 90 pounds, or 41 kilograms.

Irma, which dropped as much as 17 inches of rain on citrus- growing areas in a 24-hour period, made it impossible for farmers to reach their groves, with trees destroyed and fruit dropping to the ground unharvested, the USDA said.

Still, the USDA’s forecast was ahead of the 31 million boxes predicted by Florida Citrus Mutual, the state’s largest grower group, on Oct. 10. Orange juice for November delivery in New York fell as as much as 3.7 percent, before settling 2.3 percent lower at $1.589 a pound on ICE Futures U.S.

Florida growers group disputes USDA’s Florida orange crop estimate

Prices are also under pressure because Brazil, the top supplier, has ample stocks, is harvesting more, and will compensate for lower supplies from Florida, Burak Kazaz, professor of supply chain management at Syracuse University’s Whitman School of Management, said in a telephone interview.

Irma caused an estimated $2.5 billion in damage to agriculture, the Florida Department of Agriculture and Consumer Services said Oct. 4. Preliminary estimates show $760.8 million in damage to the citrus industry. Texas’s state farm agency has yet to release a damage estimate for Harvey, which hit the Gulf Coast region in late August.

“The path of Hurricane Irma could not have been more lethal than what it was,” Florida Agriculture Commissioner Adam Putnam said Wednesday. Groves are still under water in southwest Florida and state lawmakers are calling for immediate federal aid for producers.

©2017 Bloomberg L.P.

Crop Vigor Delivered by Honeybee Snipers

Fri, 13 Nov 2020 06:04:33 GMT

Honeybees deliver airmail crop vigor as they scurry out of a hive and collect a health package on hairy legs before delivering a booster shot into each bloom.

A field trial utilizing honeybees combined with a newly developed dispenser technology to deliver a beneficial microbe has shown efficacy in controlling two devastating blueberry diseases, in addition to supplementing yield, according to Bee Vectoring Technologies ( BVT ).

Conducted in Nova Scotia, Canada, the field test used BVT’s dispenser system to combat Botrytis blight (gray mold) and Monilinia blight (mummy berry) in blueberries. “Our yields went up quite substantially when we used the BVT system, whether alone or in combination with chemical fungicides, but they didn’t go up where we used the fungicide alone,” says Dr. David Percival blueberry research program director and professor at Dalhousie University in Nova Scotia. “The results indicate the potential for floral blight disease control and increased berry yields with the use of BVT technology. Future work will allow us to fine tune the use recommendations.”

“Notably, this was the first time we tested our honeybee delivery system in a replicated R&D study, and we got great results,” adds Ashish Malik, CEO of BVT. “Having a proven system that works with honey bees alongside our first system designed to work with commercial bumble bee hives allows us to reach a far wider market and gives us options to deliver solutions for growers based on the specific needs for their crops.”

Almost 300,000 acres of blueberries cultivated in the U.S. and Canada with a total farm gate value of $1.1 billion. North American acreage is responsible for 54% of global blueberry production.

For more information, see beevt.com .

Vegetable breeder says new tomato varieties bring high resistance to virus

Tue, 09 May 2023 14:42:15 GMT

Vegetable breeder Enza Zaden is touting 18 new tomato varieties with high resistance to Tomato Brown Rugose Fruit Virus (ToBRFV), giving growers another tool to combat the disease.

The Netherlands-based company says 1,000 hectares of High Resistance by Enza Zaden (HREZ) varieties have been successfully cultivated around the world. The varieties are completing their first season of commercial production in The Netherlands, Mexico, Canada and other key production regions, according to a news release.

HREZ varieties are available in all significant tomato types, including roma, beef, grape, cherry, cocktail and tomatoes-on-the-vine, the release said.

Enza Zaden said in the release that, until now, the only controls against ToBRFV had been strict phytosanitary measures, such as more frequent crop rotations and extra cleaning, resulting in higher labor costs. While resistant varieties are not a substitute for good phytosanitary controls, they provide additional confidence to growers, according to a news release.

The company said this is partly due to the unique resistance identified in HREZ varieties, which actively blocks progression of the virus in the plant under normal virus pressure. After the virus enters a HREZ tomato plant and starts replicating, the plant’s defense system will be activated, killing the infected cell and preventing the disease from spreading, according to the release.

“Just as islands are insulated from diseases and pests, HREZ varieties highly restrict virus accumulation. This is why HREZ varieties are named after islands around the world,” Enza Zaden Regional Marketing Manager Jean-François Thomin said in the release.

Thomin added that the HREZ varieties can help growers return to preferred planting dates and regular harvest cycles.

“In turn, growers, shippers and retailers can expect a return to predictable supply planning and consistent product quality,” he said.

The company said the effectiveness of the resistance was demonstrated in Dutch crops with HREZ varieties grown in greenhouses in areas known for high ToBRFV pressure. The same is true of commercial crops in Mexico and Canada, where growers are increasing their area of HREZ tomatoes this year as they become more familiar with the varieties, according to the release.

“As a company, our goal is to bring innovation and solutions to growers, and it is a privilege to be involved in the HREZ project that benefits not just growers, but the whole tomato supply chain, all the way to consumers,” Enza Zaden Mexico Commercial Director Antonio De Sainz said in the release.

“As a family business we have always stood shoulder-to-shoulder with partners in realizing our ambition of providing people all over the world with access to a wide range of healthy vegetables,” Enza Zaden CEO Jaap Mazereeuw said in the release. “We work to help producers grow. With HREZ we can help producers achieve reliable profitability while ensuring continuous supply of healthy vegetables.”

New study traces worldwide spread of powdery mildew

Wed, 15 Jan 2025 14:00:09 GMT

A research study at North Carolina State University has pinpointed the worldwide spread of a fungus that infects blueberry plants with powdery mildew.

The study shows that the fungus, Erysiphe vaccinii, has spread from its point of origin in the eastern U.S. to multiple continents in the last 12 years.

“We’re watching this global spread happen right now, in real time,” Michael Bradshaw, assistant professor of plant pathology at NC State and the corresponding author of research paper, said in a university news report.

Powdery mildew causes a powdery substance to cover host plants and steal nutrients and slow photosynthesis. Different species of fungus infect different plants. Powdery mildew can infect grapes and strawberries, among others.

Bradshaw examined historic and modern plant leaves infected with powdery mildew from North America, Europe, Africa and Asia. Researchers discovered the first infection of powdery mildew outside North America on a farm in Portugal in 2012. The study traced its spread, with one strain of E. vaccinii in China, Mexico and California, and another strain in Morrocco, Peru and Portugal.

The research team attributes the spread from nursery plants.

“This is a hard organism to control,” Bradshaw told the university. “If you’re sending plant material across the world, you’re likely spreading this fungus with it.”

The research team estimates the blueberry industry invests between $47 million to $350 million annually to reduce powdery mildew.

The researchers said there is an imminent threat of powdery mildew in blueberry-producing regions such as the Pacific Northwest, where conditions favor the fungus.

“Disease spread could also be impacted by agricultural conditions,” Bradshaw told the university. “Some areas that grow blueberries in tunnels, or enclosed areas, seem to have worse disease outcomes than areas that grow blueberries outdoors without any covering, like in North Carolina.”

California expands sweet orange scab quarantine

Mon, 06 Jan 2025 19:09:43 GMT

The California Department of Food and Agriculture says it has expanded the sweet orange scab quarantine in Santa Ana area of Orange County.

Sweet orange scab is caused by the fungus Elsinöe australis. Infected fruit has a corky appearance, and the fungus can stunt young nursery trees or new field plantings and cause premature fruit drop.

The USDA’s Animal and Plant Health Inspection Service and the CDFA expanded the quarantine September 2024 due sweet orange scab detections in plant tissue samples collected from residential properties in Riverside County.

A map of the expanded boundary can be found online .