Getting out of the weeds
Testing a promising new strategy to counter herbicide resistance. | 8
Battling Black Rot
What every grape grower needs to know. | 12
Insect pest control
The guide to pest control for strawberries, sweet corn and wine grapes. | 18
February 2025
Neudorff North America is an innovative leader in ecologically responsible pest solutions for farmers, turf professionals, nursery and greenhouse growers.
Our effective and affordable solutions for disease, insect pests, pest slugs and snails have limited impact on applicators, beneficial insects and the environment. They are an important part of integrated pest management programs.
Neudorff has you covered from the ground up.
®
Powerful disease protection for your fruit and vegetable crops with a fraction of the copper found in other copper fungicides.
The soft-bodied insect specialist. Kills aphids, mites and whiteflies on contact in a wide range of crops. A great tank mix partner.
A summer and dormant oil. Controls all life stages of insects and mites, and supresses powdery mildew.
A durable iron phosphate bait that offers excellent crop protection from slugs and snails.
A durable, fast acting spinosad bait, active against a variety of ants, cutworms, spotted wing drosophila and wireworms in a wide range of crops.
A lingering pathogen
Once it shows up, Phytophthora capsica is there to stay. 8
Getting out of the weeds
PC in a pepper field. See page 24.
Photo by Ontario Ministry of Agriculture, Food and Agribusiness/Amanda Tracey
B.C.’s only weed scientist, Jichul Bae, takes the fight underground to test a new strategy in reducing weed pressure.
BY J.P. ANTONACCI
What should you monitor, keep record of and how can you start the season off protected? Perennia outlines it all.
BY KATARINA VUCIC
The latest in potatoes Canadian Potato Summit taps into industry and agronomic trends.
BY BREE RODY
Growers work hard to meet the demands for produce that is not only abundant and fresh, but also visually appealing and most importantly, safe to eat. And the stakes are particularly high when addressing the significant disease, weed or insect pest challenges that persistently threaten crop yield, quality and marketability.
Effective pest management is far more than a line item in the budget; it’s a principle in sustainable farm operations and the agri-food industry at large. From insects and weeds to fungi and pathogens, the threats a crop can face at any given time are broad and complex, which is why dedicated research is essential to help guide effective decisions and unearth new, reliable solutions growers can implement on-farm. Moreover, tightening farm margins and a push toward reduced pesticide use, while maintaining good stewardship of current herbicide active ingredients,
and Agri-Food Canada is working to find new solutions for cranberry farmers in B.C. with winter herbicide applications. In addition, you’ll find insights to help fight black rot in grapes on page 12, and on page 24, OMAFA’s Amanda Tracey shares the devastation one pathogen can cause and the limited toolkit growers can use in response to an infection.
To continue the theme of supporting effective decisions, this issue also includes insect pest management charts on pages 18, 20 and 22 for wine grapes, strawberries and sweet corn. We thank the numerous agronomists and manufacturers for their contributions to these charts. Collectively, we strive for the most accurate and up-to-date information, but in the case of any discrepancies, please refer to your provincial crop protection guide or consult the company representative in your growing region.
“Effective pest management is far more than a line item in the budget.”
reflect the broader need for a portfolio of sustainable, economical and environmentally friendly practices that growers can realistically implement.
In this issue, we delve into some of the latest research, tools, and strategies in pests and diseases that our lively industry contributes to that goal. On page 8, you’ll read about how Jichul Bae of Agriculture
As you dive into the strategies and solutions you may need for the 2025 growing season, we’d love to know how Fruit and Vegetable magazine can help guide your on-farm decisions. If you’re at the Ontario Fruit and Vegetable Convention on Feb. 19-20, please stop in to visit with us at Booth #500, or connect with us by emailing fruitveg@annexbusinessmedia.com. •
Broad-spectrum disease control that lasts.
You go to great lengths to protect your apples. So does new Merivon®. It’s the advanced fungicide that helps maximize yields with broad-spectrum disease control and two modes of action. But it doesn’t stop there. Merivon also offers unique Plant Health Benefits1 and extended residual. Because like you, Merivon was made to go the distance. Visit agsolutions.ca/horticulture to learn more.
A new program will help the agriculture industry on Prince Edward Island (P.E.I.) continue to build capacity and improve training for those working in it.
Through the Sustainable Canadian Agricultural Partnership (Sustainable CAP), Agriculture and AgriFood Canada and the P.E.I. Department of Agriculture are investing over $300,000 in the Agriculture Labour Sub-Program. This new program stream will provide farmers and agricultural organizations with access to funding for a variety of initiatives focused on improving the workforce. These include but are not limited to:
• Recruitment missions;
• Developing on-farm resources for employees with English as a second language;
• Workforce training and professional development opportunities;
• Developing models and strategies for employee childcare and transportation;
• Participating in and attending job fairs and trade shows;
• Other fees, accommodations, and registrations related to recruiting and retaining staff.
“From potatoes to beef and dairy – agriculture is one of the most important industries on the Island,” said Lawrence MacAulay, federal minister of agriculture and agri-food, in a statement. “By investing in people and providing new training and development opportunities, we can help ensure the sector remains strong for generations to come.”
Chris Hedges of Vanessa, Ont., has been elected as the new chair of the Ontario Apple Growers (OAG). Previously the organization’s vice chair, Hedges takes over from outgoing chair Brian Rideout of Blenheim, Ont., who has led OAG since December 2023. Past OAG chair Cathy McKay has been elected as the new vice-chair.
“These are challenging times for Ontario’s apple industry, and I appreciate the trust
my fellow growers have put in me to lead this organization,” says Hedges. “Ontario apples are a popular, year-round fruit choice and we will continue to advocate for the legislative support we need from all levels of government to produce food in an economically sustainable way.”
Hedges, a firstgeneration apple grower, farms with his wife in Norfolk County. He also owns and manages
Ontario Orchard Supply, selling orchard supplies to fellow apple growers.
As a director, Hedges has been active with the OAG Risk Management Committee, as well as the Ontario Agricultural Commodity Council and the Fruit & Vegetable Growers of Canada Apple Working Group. He was also involved with the board of the International Fruit Tree Association for many years.
McKay and her
husband Marvin Stevenson farm near Port Perry, Ont., growing 22 apple varieties on Nature’s Bounty Farm, a pick-yourown business that also includes a seasonal farm market and agritourism activities.
In addition to Hedges and McKay, the OAG board includes directors Keith Wright, Jeremy Veens, Joe Van De Gevel, Brian Gilroy, Kyle Ardiel, Robert Shuh, Kara Pate and Quinton Gibson.
Interested in growing garlic in Ontario? Travis Cranmer, OMAFA vegetable crop specialist for Alliums, Brassicas and leafy greens, has announced a one-day workshop covering garlic production and pest management.
This workshop will cover every part of garlic production in Ontario, including cultivar selection,
soil testing, pest and disease identification, and curing and storage. Special emphasis will be put on Fusarium management.
The workshop will take place in Guelph, Ont., on April 16, 2025. Pre-registration is required.
Scan the QR code or visit onvegetables.com for more information.
Kristen, Marie, Maryn, Nicole, Pete, Roman, Sarah - Inside Sales
Faced with a resilient and adaptable foe, British Columbia’s only weed scientist is taking the fight underground.
B.C.’s only weed scientist tests promising new strategy to counter herbicide resistance.
BY J.P. ANTONACCI
Jichul Bae of Agriculture and Agri-Food Canada is testing a new strategy for applying herbicide to fruit and vegetable crops in B.C.’s Lower Mainland, where herbicide-resistant weeds are a thorny issue for growers.
Working out of the Agassiz Research and Development Centre in Agassiz, B.C., Bae thinks he has found a “weak link” in the life cycle of perennial weeds like field horsetail and morning glory that growers can exploit to significantly reduce weed pressure.
The idea is to spray fields earlier in
ABOVE
the season – in late January and early February, while crops are dormant or not yet planted – to target the weed’s subterranean support system, which damages the plant’s reproductive organs and keeps weeds from gathering energy and sprouting.
After two years of field trials, the results have been dramatic. Spraying earlier has reduced weed pressure by as much as 60 per cent, allowing growers to skip some later-season herbicide applications altogether.
“With using our winter application strategy, (growers) would be able to reduce two herbicide applications in the growing season,” Bae says. That saves money, puts fewer chemicals in
Jichul Bae, AAFC is testing new strategies in British Columbia to combat herbicide resistance.
the soil and waterways, and avoids herbicide damage to the crops while chipping away at the problem of herbicide resistance.
It may seem counterintuitive to spray fields before the weeds pop up, but early application gives crops a fighting chance, while waiting can actually make things worse, Bae explains.
“If you spray herbicide in April, May, or June, then it’s too late,” he says, as that only kills the tops of the weeds poking out of the ground, while the base of the plant lives on to gather energy and sprout another day. “So (growers) spray herbicide at the wrong time and they just stimulate the below-ground growth,” Bae says.
The milder weather and long growing season that benefit B.C.’s fruit and vegetable crops also open the door for perennial weeds, which survive and grow stronger in the colder months while the crops go dormant. “Thanks to the warmer climate, those creeping perennial weeds have better regenerative capacity, because they have a longer period to accumulate energy in their reproductive organs,” Bae explains.
“The problem is perennial weeds are seldom controlled by a single herbicide application” because they have a “deep and extensive” underground network of reproductive organs.
Targeting that network zaps perennial weeds for good, letting crops thrive. “Then the following season they have less weed pressure, and they produce more berries,” Bae says.
Some B.C. potato and carrot growers are starting to adopt Bae’s early season spraying scheme based on promising results from two years’ worth of trials at the AAFC research farm in Agassiz, east of Abbotsford. Bae has seen the most enthusiastic uptake among cranberry growers, whom he says are “very open to research and new technology.”
Winter herbicide application is being tested on cranberry plots at B.C.’s cranberry research farm, which is funded by AAFC, the province, and private industry. Experiments there saw weed pressure reduced by up to 60 per cent.
“Cranberry growers, they love winter application now,” Bae says with a smile.
Herbicide resistance is a major concern in B.C., especially among fruit and vegetable crops, which are outclassed by cash crops in terms of economic value and the resultant attention paid to them by government and industry.
Bae says “regional and seasonal effects” make B.C. weeds more potent and longer-living than those in Ontario or Quebec. The province’s warmer climate means seeds germinate better and stay viable longer in the soil, while flooding cranberry plants at harvest has the unfortunate side effect of creating ideal conditions for field horsetail spores to spread.
“Here I found out the weeds are flowering longer,” Bae says, noting perennial weeds accumulate energy over a longer period and spread their vegetation further than their counterparts in the colder central provinces.
Shortly after getting to B.C. in 2017, Bae tested various weed samples and immediately found widespread – and previously unidentified – resistance to the most commonly used herbicides.
“Before I came here, nobody did a herbicide resistance survey. We had no idea if we had herbicide-resistant weeds or not,” he says. “So, the growers were not aware of the herbicide resistance,” thinking it more of an issue on the Prairies.
“It’s not like Ontario and Quebec. They have such great data,
so the growers are fully aware of which (weed) is resistant and which herbicide you can use or not,” Bae continues. B.C. had next to no similar information, because, until recently, there has not been a provincial weed specialist or scientist.
Bae decided to fill that knowledge gap himself, assembling a team to fan out into three carrot and pumpkin fields. “We thought, okay, it’s going to take time,” he recalls. “But no. The first sample we got, it was resistant.”
The pandemic halted the testing program, which restarted last year. Bae expects to find more herbicide-resistant weeds, which is not good new for growers but will, he hopes, startle them into taking a different approach to weed management.
And new approaches are needed, since “weeds are developing very fast,” Bae says. He sees weeds that were only resistant to one type of herbicide develop resistance to multiple types over the course of a single year. “Within a very short period of time, they keep upgrading their traits,” he says.
In recent years, growers have called Bae complaining that the herbicides they count on have stopped working. “The growers here used the same herbicide over and over, which promotes the herbicide resistance development,” Bae says, noting growers have “very limited options” when it comes to alternative herbicides.
“The declining access to herbicides poses a potential threat to the growers right now,” Bae says. “The main reason is the lack of herbicide discovery for horticulture crops. The last time we had a new active ingredient for horticulture crops was 30 years ago.”
To make matters worse, weeds in Washington state are even more broadly resistant to herbicides, and the major winter floods of 2021 swept American weed seeds north into the Lower
Mainland. As Bae puts it, “There’s no border for weeds.”
The cost of letting weeds choke out B.C.’s fruit and vegetable industry could be catastrophic.
“In Canada, weeds alone cause about $528 million in crop yield loss annually, making them one of the most expensive pests in agriculture,” Bae explains. “Based on my previous trials, if we don’t control weeds (in B.C.), then we’d lose 40 percent of sweet corn yield, 50 percent of carrot yield, 60 percent of potato yield, and 65 percent of red beet yield.”
Field vegetables are more susceptible to weed pressure than fruit crops, but none of B.C.’s horticulture crops are naturally resistant, so everything is threatened. Bae estimates potential yield loss in blueberries at 15 to 30 percent and cranberries up to 25 percent. As these are not giant harvests to begin with, reductions of that scale would cripple the industry.
Inspired by their Ontario counterparts, some B.C. growers are starting to experiment with machines designed to
pull weeds automatically. But for many, the cost is prohibitive.
“Because of the size of the horticulture growers (in Canada) compared to the U.S., we can’t afford it,” Bae says.
”In Canada, weeds alone cause about $528 million in crop yield loss annually, making them one of the most expensive pests in agriculture.”
AAFC researchers are working with academics from university engineering departments to design “affordable, smallscale robotic weeders,” Bae says. But with current weed-pulling technology prohibitively expensive and “limited access” to useful herbicides, growers shell out big bucks for labourers to handpick weeds.
Bae knows of one cranberry grower
who spent $500,000 on labour in a single season and still had issues because his workforce got to the farm a couple months too late to pluck out the problem weed –field horsetail – in time. “He had a very small patch of horsetail … and after two years, (it covered) the entire field,” Bae says.
Labour-intensive hand-weeding “is effective against the annual weeds, but not the perennial weeds,” he explains. That makes his innovation to spray in the winter especially important, as it is one of the few new strategies growers can employ.
Some B.C. growers will plant winter cover crops to reduce weed pressures – with the added benefits of boosting soil health and biodiversity – or test technology that targets weeds. But once revenue is threatened, herbicides are reintroduced to protect their crops and yields.
Bae understands the economic pressures, but is committed to helping growers reduce herbicide reliance and incorporate strategies that are sustainable and environmentally friendly. •
24_014597_Fruit_n_Vegetable_FEB_CN Mod: December 13, 2024 12:07 PM Print: 12/27/24 page 1 v2.5
Each year, CABEF helps students to pursue rewarding agri-food careers through seven $2,500 scholarships. We’re looking for the future leaders who will help this industry meet tomorrow’s challenges.
Do you know someone who needs to fund their future in agri-food? Tell a student today.
Scholarship application deadline is April 30, 2025
Want to help support the next generation of agri-food leaders?
Become a “Champion of CABEF.” This program allows your organization to directly sponsor a deserving student. Contact CABEF at info@cabef.org.
With the potential for total crop loss, it’s crucial to know signs, symptoms and management strategies for Black Rot.
BY KATARINA VUCIC, VITICULTURE SPECIALIST, PERENNIA
Black rot (Guignardia bidwellii (Ellis)) is a highly destructive fungal disease that, under the right conditions, infects the leaves, shoots, berries and cluster stems of grapevines. It is the main disease Nova Scotia grape growers contend with every year. While susceptibility to black rot varies significantly between grape varieties, it poses a threat to all types, including American, French hybrid and Vinifera cultivars in both yield and grape quality. If left untreated, it is extremely difficult to eradicate and because of its complex life cycle, has the potential to cause total crop loss and ongoing damage year after year.
Black Rot is often regarded as a major challenge for organic grape growers, due to the limited control methods available and the significant crop losses caused by berry infections. The Fungus is seldom found in dry, arid regions and instead thrives in warm, humid and rainy climates such as Nova Scotia and Ontario.
SUSCEPTIBILITY AND WEATHER CONDITIONS
Ascospores require at least 3 mm of rainfall to be released, while conidia need 10 mm. Infection occurs most rapidly when there is at least six hours of wetness and temperatures range from 18.5 C to 26.5 C. Outside this range, a longer wetness period is needed. Ascospores are spread by wind and rainsplashed conidia can quickly disperse in wind-driven rain. Nova Scotia is particularly prone to Black Rot outbreaks because of its cool and humid springs.
SYMPTOMS AND SIGNS
rainy weather continues. These spores need free moisture for release and a prolonged wetness period to cause infection. Wind, along with rain, helps disperse the spores.
Symptoms of black rot infection typically appear around 2 weeks after the initial infection. On leaves, it begins as small, round brown spots that can expand, developing light brown centers and dark edges. After several days, numerous tiny black fungal fruiting bodies, known as pycnidia, form. The disease primarily affects young leaves, as older ones are more resistant. Black rot can also manifest on shoots, petioles and tendrils as irregular brown to black lesions, with pycnidia appearing within these lesions, just like on the leaves.
Spores are formed in the pimple-like structures on all infected tissues and can spread black rot throughout the canopy if warm,
Infection is possible from flowering through to the berry ripening stage. Berries are most vulnerable to infection three to five weeks after bloom. Susceptibility decreases by week six to seven post-flowering. Infection on berries start as pale spots that turn brown within 24 to 48 hours. The grape berry surface then becomes wrinkled and small black dots (pycnidia) form. Eventually, the berries become black, hard, shriveled and fully mummified.
CONTROL AND MANAGEMENT STRATEGIES
It is important to understand that Black Rot overwinters. Infection from the previous year provides inoculum for the current year. The inoculum survives the winter in mummified grape berries, rachises, and canes that were infected in the previous season. Spores generated in these infected tissues can be carried by the wind (ascospores) or splashed by rain (conidia) to infect leaves, shoots, tendrils, and berries.
Monitoring
• Scout for mummified berries in spring on ground and vines.
• Obtain historical pest information from previous growing season.
• Monitor leaves around bud break.
• Monitor fruit until Veraison.
Site selection
• Choose a site with good air circulation and favorable conditions for leaf drying when establishing a new vineyard.
• Avoid planting in low-lying or poorly drained areas.
• Train vines onto higher trellises to improve air flow and ensure better fungicide coverage in the canopy.
Sanitation
Maintain a weed and tall grass-free area around the fruit planting. This helps reduce humidity and allows the vines to dry more quickly, thereby limiting fungal infections.
Cultivation
• Remove diseased fruit throughout the growing season, whenever possible.
• Remove and dispose of infected vines during dormant pruning.
• Avoid dropping mummies onto the ground; instead, prune directly onto tarps or carts and ensure all diseased material is removed from the vineyard.
Not all cultivars are susceptible to Black Rot equally. Below is a short list of several cultivars and susceptibility ranked from Low to High. Check the vulnerability of cultivars before planting to prevent heartache down the line.
Low Medium High
L ‘Acadie Frontenac Baco Noir
NY Muscat Lucie K Cab Franc
DeChaunac Marechal Foch Riesling
Leon Millot Seyval Pinot Noir Vidal
Berries are most susceptible to infections between flowering and bunch closure. Consequently, fungicide applications need to focus on this period. The first fungicide spray should be targeted for Spring when the vines reach 3-5 leaves. This will protect both leaves, protecting both the leaves and shoots from infection.
Managing primary infections in the spring reduces the need for fungicide applications later in the season. Follow label instructions for early-season sprays, ensuring proper coverage and protection of vulnerable tissue. Vines left unprotected early in the season may become infected, causing inoculum buildup and leading to berry infections. The threat will vary each year based on the disease level in the vineyard from the previous season and the current weather conditions. These factors may require an early-season spray or an additional fungicide application after bloom.
200+ Exhibitors, over 100 industry speakers, a community full of fellow growers to network with, all under one roof.
FEBRUARY 19–20, 2025
NIAGARA FALLS CONVENTION CENTRE
Canadian Potato Summit taps into industry and agronomic trends.
BY BREE RODY
Growers can rarely rest on their laurels. Being proactive is better than being reactive. And good things take time to see.
These were insights from the fifth annual Canadian Potato Summit, which was held virtually Jan. 15.
The main purpose of the Summit, hosted by Fruit and Vegetable sister publication Potatoes in Canada is to bring growers together and keep them updated on the latest research, findings and trends. The virtual format allows the information to be delivered efficiently, with speakers hailing from Atlantic Canada, Manitoba and everywhere in between.
The event kicked off with a session that covered numerous aspects of the business from a grower’s perspective.
United Potato Growers of Canada GM Victoria Stamper delivered a business update on behalf of UPGC, which covered the status of the growing seasons across the country – planted acreage, yields and broader trends affected by weather and the like.
Utilizing current and historical data, Stamper and UPGC’s data showed that Canada remains a
ABOVE
potato production powerhouse.
“Although our planted acreage haven’t reached the peak – back in 2003, over 457,000 acres – we can see that production has surpassed [previous levels] with the assistance of steadily increasing yields.”
For the 2024 growing season, estimates put the season at just over 391,000 planted acres, nearly 384,000 harvested acres, 330.9 overall yield, and production of nearly 127,000,000 hundredweight, a modest increase (0.3 per cent) from 2023. That slight increase came after some recent revisions to StatsCan’s 2023 numbers – initially, the production amount was expected to be lower this year than last year’s. The result? It was a record 2024.
That doesn’t mean every region shared similar spoils. It wasn’t all sunshine in the east, for example, although in this case, the rainy days were welcome.
“We had a lot of consistent rain in New Brunswick, P.E.I., Quebec, even into Ontario,” said Stamper, noting this was almost the opposite of the 2023 season. Harvest – not simply what is pulled out of the ground, but what is suitable for storage – increased in most eastern regions, while most western regions saw modest decreases in harvest. Stamper said in her work, most of the growers with whom she’s spoken
AAFC’s Judith Nyiraneza, a specialist in regenerative soil practices, has studied a number of field plots that were subject to different combinations of regenerative practices.
have been pleased with the harvest.
Alberta and Manitoba also saw slight decreases in planted acreage thanks to some decrease in processing sector acreage. “We are slightly down overall, [with] most of that in the west.”
Stamper’s outlook also pointed to trends and changes at home, and what the development of Canada’s economy means for the potato sector. Quickservice restaurants such as Tim Hortons, McDonald’s, Starbucks and A&W (the top purchasers of potatoes) have mostly seen small increases in their footprints, with the exception of Tim Hortons, which had a small (0.8 per cent) decrease. More than 85 per cent of Canadian households purchase potatoes, and it continues to be the driving force between high-demand items such as frozen French fries.
Stamper’s talk also discussed trends and developments in the U.S. and Europe with some insight into what this means for Canada.
Naturally, this resulted in the biggest question on everyone’s minds: tariffs.
Newly sworn-in U.S. president Donald Trump has made numerous promises prior to his inauguration to apply 25 per cent
tariffs on imports from Canada, at times as a threat times as a threat, at other times in reference to what he views at other times in reference to what he views as a trade deficit between the two nations.
There’s no denying that Canada is a net exporter of potatoes, and that the U.S. is an important trade partner for many of Canada’s industries, including potatoes. Numerous groups have expressed worries that blanket tariffs would cause significant damage to the industry. “Our government and our associations in Canada are definitely lobbying and are making sure people are aware that tariffs are not good for anyone on either side of the border,” said Stamper.
Editor’s note: At press time, Jan. 21, 2025, no executive order has been made to impose tariffs on imports from Canada, nor have any concrete plans been outlined since the Jan. 20 inauguration.
Other pressing matters include a potential rail strike, port strikes, the low exchange rate, erratic weather and more.
Two sessions included information on key pests. Manitoba Agriculture’s Vikram Bisht delivered an update on Manitoba’s growing
season and condition, with a focus on pests and diseases. AAFC’s Christine Noronha delivered a special presentation focused on Colorado potato beetle (CPB) and management strategies for the pest.
Left uncontrolled, CPB populations can cause yield loss of anywhere from 40 to 80 per cent. Currently, with CPB’s adaptability and history of developing resistance to major insecticides, prevention is less of a realistic option than management.
Biological control is one common method – including releasing insect predators, such as soldier bugs. Regardless of release methods, Noronha described this method as a strong biocontrol agent. Mechanical control is another method. A plastic-lined trench in a field could serve as an effective trap for walking beetles – provided the slope is right. In the right conditions, Nornha said studies show a marked improvement from this mechanical control.
For those still using insecticide, said Nornha, rotating insecticides is important, as it will help delay resistance development.
CPB is among the top pests of major concern in Manitoba, according to Bisht, as well as aphids and European corn borer (ECB). For aphid tracking, 2022
February
represented a peak for aphids trapped at eight sites. However, 2023 and 2024 saw a lowering from the peak – with a twist, says Bisht. “In 2023, when our numbers were medium – not too high – our numbers of green peach aphid and potato aphid trapped were very, very high,” he explained. While 2024 saw fewer, Bisht pointed to the “late surge” observed as a pain point.
For diseases, Bisht covered the major concerns among Manitoba growers – late blight, powdery scab, black dot and others. One item of note was an increase in spraing incidence and intensity for potato mop top virus (PMTV) in storage tubers, over the storage period. Research work to better understand the virus will continue in the province, says Bisht.
AAFC’s Erica Fava and University of Guelph’s Vanessa Currie delivered highlights from the 2024 National Potato Variety Trials conducted by AAFC.
The project’s objectives are to come up with a “superhero-type” potato with desirable traits – early maturity, pest and disease resistant, heat tolerant and more. “That’s an awful lot to ask,” Fava said. With nine trial locations in markets that were key for various types of potato products (French fries, fresh market potatoes and chips), a total of 39 selections were made, spanning French fry, fresh market (divided into white and red) and chip.
Even with all those traits in mind, trials showed that size matters beyond aesthetics
– affecting yield, marketability and more.
For example, for fresh market potatoes, Fava noted positive feedback on varieties VF170089-26 and F170045-06, “However, it was mentioned that the size profile [for both] was a concern.” And, although total yields for both were comparable to Norland, the marketable yields were comparably low partially due to the size profile.
Some varieties are available for nonexclusive licensing through agriculture. canada.ca
Judith Nyiraneza, an AAFC scientist and a specialist in regenerative soil practices, discussed how such practices related to potato yield. Soil with high organic matter,
said Nyiraneza, has better structure, water retention (better defense against drought), improved biological productivity and better nutrient recycling. It’s important for growers to commit to practice that increase soil organic matter, said Nyiraneza.
“Combining several practices might be the key,” she said, which is why the research team explored combinations of crop residue and organic amendments, such as manure at different stages of composition. Using 2022 modelling from the Quebec Living Lab that looked at estimated soil organic matter over the next 100 years, Nyiraneza highlighted the various practices that, even on their own, raise soil organic matter.
The modeling was based on a clay loam with about four per cent soil organic
matter, with a corn-soybean rotation. “If you don’t do anything… as you can see, it’s business as usual,” said Nyiraneza, pointing to the trendline over time that indicated that the soil organic matter stayed at just above four per cent over the next 100 years. However, other management practices such as no-till, manure, intercropping, winter wheat plus cover crop and others saw significant increases in soil organic matter over the next century.
Nyiraneza highlighted two studies from the Atlantic Living Lab that looked at the effects of such practices on potatoes. The first study, which began in 2017, looked at cover cropping both with and without manure. Cover crops resulted in higher potato yield, with the top contributing cover
crop being pearl millet. Manure showed a clear trend of improved soil health metrics.
The second study, established in 2019, compared primary, non-inversion shallow tillage (ST) and moldboard plowing (MP). The two tillage regimes resulted in comparable total yield, marketable yield and specific gravity.
Combining practices is a good strategy, said Nyiraneza, and it should be considered whenever possible.
But she also emphasized although such practices will result in soil health improvements, such improvements may take a while to be seen. But, like many other management practices that benefit potatoes and the land on which they’re grown, that does not mean they’re not worth it. •
recommended.
Do not enter, or allow worker entry, into treated areas within 15 days after application to carry out girdling or cane-turning activities or within 7 days after application to carry out training, tying, hand harvesting, hand pruning and thinning. For all other activities including mechanical harvesting, do not enter, or allow worker entry, into treated areas until pesticide residues have dried.
Western flower thrips
Two-spotted spider mite
Spotted wing drosophila
Multicoloured Asian lady beetle
Leafhoppers
Japanese beetle
Grape phylloxera (leaf form)
Grape berry moth (second generation)
Grape berry moth (first generation)
European red mite
Climbing cutworm
Max. applications per season
Days between applications
Re-entry period (hours)
Pre-harvest interval (days)
Aerial or ground
Soil or foliar
of 2 application per year for climbing cutworm.
Do not enter, or allow worker entry, into treated areas within 15 days after application to carry out girdling or cane-turning activities or within 7 days after application to carry out training, tying, hand harvesting, hand pruning and thinning. For all other activities including mechanical harvesting, do not enter, or allow worker entry, into treated areas until pesticide residues have dried.
21 days to perform girdling and turning, 13 days for training, bunch thinning, hand pruning, tying and leaf pulling, 12 hours for all other activities
Fungicide effective against the pest SSuppression only This table is presented as a guide only. It is strongly recommended that users refer to crop protection guides and product labels for specific details prior to purchase and/or use
*Actual technology may not be exactly as shown.
Experience a new level of control with our unique binding action.
Talk about technology you’ll get attached to quickly. Cevya® fungicide uses exclusive binding activity to control biotypes that may be resistant to other fungicides, including Group 3-tolerant strains. This hook-like action delivers fast and continuous control of key diseases in blueberries, grapes, apples, pears, stone fruits, potatoes and vegetables. Visit agsolutions.ca/horticulture to find out what it can do for you.
Japanese beetle/black vine weevil
Tarnished plant bug specifically, meadow spittle bug and bud (clipper) weevil. Minor use: Suppression of black vine weevil adults ( Otiorhynches sulcatus )
Also: spittlebug
Fungicide effective against the pest SSuppression only *see note This table is presented as a guide only. It is strongly recommended that users refer to crop protection guides and product labels for specific details prior to purchase and/or use
Do not apply within 7 days of harvest of sweet corn and forage (of sweet corn, field corn, seed corn, popcorn, and sorghum). Do not apply within 14 days of harvest of grain and stover.
Also effective against beet armyworm, tomato fruitworm and grasshoppers.
Do not apply within 28 days of stover
or within 7 days of forage harvest.
For sweet corn, do not enter, or allow worker entry, into treated areas within 7 days after application to carry out detasselling or hand harvesting activities. For all other activities, do not enter, or allow workers, adults, children or pets to enter into treated areas until pesticide residues have dried. Do not apply within 7 days of harvesting. Do not apply within 28 days of fodder harvest or within 7 days of forage harvest.
For sweet corn, do not enter, or allow worker entry, into treated areas within 7 days after application to carry out detasselling or hand harvesting activities. For all other activities, do not enter, or allow workers, adults, children or pets to enter into treated areas until pesticide residues have dried. Do not apply within 7 days of harvesting. Do not apply within 28 days of fodder harvest or within 7 days of forage harvest.
Fungicide effective against the pest
Suppression only
is presented as a guide only. It is strongly recommended that users refer to crop protection guides and product labels for
GET PROTECTION FROM DAMAGING SOIL-BORNE DISEASES AND NEMATODES WITH VELUM RISE.
Protect your potato crop with an in-furrow application of Velum® Rise fungicide/nematicide. Velum Rise delivers excellent control of soil-borne black scurf, stem and stolon canker caused by Rhizoctonia solani It also offers suppression of black dot and nematodes which are some of the causal agents of the potato early dying (PED) disease complex.
Rise to the challenge and get the performance you need with Velum Rise.
Once it shows up, Phytophthora capsici is there to stay.
BY JEFF TRIBE
Phytophthora capsici (PC) is like the very worst of party guests. Showing up uninvited, it hangs around far too long. And if it happens to have too much to drink, the real trouble starts.
“It is a really big concern,” says Amanda Tracey, vegetable crop specialist with the Ontario Ministry of Agriculture, Food and Agribusiness (OMAFA).
That concern is two-fold, Tracey continues, including the undeniable damage an infestation can do, and secondly, the limited toolkit producers have to respond, against the negative backdrop of more extreme climate events.
“I wish there was more we could do about it.”
Different qualities from different forms of the shape-shifting soil-borne pathogen make PC a persistent and powerful threat to a range of commercially grown fruiting vegetables and cucurbits.
The list of fruiting vegetables affected includes tomatoes, peppers and eggplant says Tracey, as well as cucumbers, melons, squash, zucchini and snap beans.
“All of these as well.”
The pathogen’s oospore form is a hardy, resting
ABOVE
spore which can remain viable in soil for 15 years. The length of overlap extends well past a strategy of denying survival on host material through rotational cropping, although a three or four-year crop rotation can be a positive factor versus a shorter time period.
“The more you plant a host crop, the more you are building a lot of these spores in the soil,” said Tracey. “And the higher the load, the more risk of disease.”
Under the right conditions, PC oospores can also produce zoospores, a form with the ability to sense potential physical hosts and a tail providing mobility to seek them out.
“They can move through the water to get to that host and infect it.”
PC’s effects vary from crop to crop. It attacks peppers aggressively through their roots and spreads, shutting down vascular tissue and resulting in rot, the fruit reduced to ‘dried up mummies.’ It results in vine decline in tomatoes, the fruit slick, smooth and shiny with greyish-brown lesions,
Phytophthora capsica stem lesions causing vine decline in tomatoes. The discoloured, ripe fruit is also infected and has turned into a ‘water balloon.’
This volume, presents the latest pomological research on the production, postharvest handling, processing & storage, & information on marketing for a selection of temperate fruits. With chapters from fruit experts from different countries of the world, the book provides the latest information on the effect of climate change on fruit production, organic fruit growing and advanced fruit breeding, the nutraceutical value and bioactive compounds in fruits and their role in human health, and new and advanced methods of fruit production.
Phytophthora capsica in a pepper field, illustrating an area that has been infected and the damage it can do to pepper plants, including wilting and eventual death.
worthless ‘water balloons.’ Fungal growth on cucurbits resembles powdered sugar says Tracey, their vulnerability elevated by their vine support structure.
“The fruit is touching the soil so they tend to get infected rather quickly.”
Traditionally, PC presents more of a problem later in the season when soil warms up, the activity of the pathogen tending to be higher in July and August.”
However, the presence of excess water is also a defining risk factor, exacerbated by a weather pattern featuring more extreme storm activity, more heavy rains throughout the season.
“Once you get standing water or saturated soil, it really helps the disease to spread,” said Tracey.
As an example, 2024 in southwestern Ontario featured a wet planting period, dry period, and then another stretch of wet weather. The 2023 season featured a seven-to-nine-inch one-day rain event in Chatham/Essex a couple of weeks into tomato harvest. Ripe fruit in near-ideal conditions for the pathogen to spread proved extremely vulnerable.
“There were guys whose crops turned into water balloons,” said Tracey. “It can be pretty devastating.”
The response to an outbreak is twofold. Producers do have access to chemical agents which are applied to the soil. However, they are suppressive rather than corrective,
their efficacy limited to a six-to-eight-week period, and additionally, the soil application may only be applied once per season.
There are foliar treatments which can be applied throughout the season, however they must be done more regularly. Additionally, if a product is used as a soil treatment, it cannot as a foliar treatment.
Planning mitigation around peak periods of potential infection is one strategy, says Tracey.
“Knowing when you tend to get infection is important.”
However, as 2024 illustrated, that prediction can be increasingly difficult.
“It really depends on the year, which is another tricky aspect for growers to deal with.”
Additionally – or alternatively – it is recommended farmers till down infected areas in order to limit the disease’s spread. PC infection tends to begin in wetter, lower-lying areas and go outward from there. There is potential to slow that process, preventing more severe damage in the rest of the crop by acting quickly.
“The sooner you can get in there, the better,” Tracey emphasized. “By leaving the plants there, you are letting the pathogen grow and produce more spores.”
Pre-emptive, rather than reactive action is also highly recommended when dealing with any soil-based pathogen, especially PC.
“Our chemical counter options aren’t
very strong, so trying to do mitigations ahead of time and minimizing the risk would be helpful for a lot of people. I would like to stress cultural control options can help minimize the risk of serious infections.”
That list begins with the longest possible crop rotation for host species, in order to limit pathogen build-up and levels in the soil.
Secondly, water management, proper drainage to remove excess amounts efficiently.
“And get any standing water off the field as quickly as possible.”
Third, irrigation strategies play a role says Tracey. Drip is superior to overhead irrigation, given the splashing water associated with the latter may carry pathogens from the soil, onto plants.
Plastic row covers used in some fresh vegetable applications can be a related factor, in that they limit ‘splashing’ and its associated risks.
Producers might also consider hilling or mounding, given that physically elevates plants from damper soil conditions that PC loves.
Weed control may also have a role in pathogen suppression. Although there is not a lot of hard data, the potential exists weeds can be compatible hosts.
Finally, farmers should recognize the dangers of physically spreading the disease. When they are moving equipment, they are potentially also moving pathogens.
“Once it’s there, it’s there,” said Tracey. Its presence can be hard to quantify in terms of percentage out of 100, for example, however resting spores have been confirmed in Essex, Kent, Elgin and Norfolk Counties.
“I’m not saying it’s exclusive to those,” said Tracey, who suspects its presence is more prevalent than recognition thereof.
“I do believe it is more widespread than we believe it is or have proof for. I would say a lot of people have it and don’t know it.”
The tenacious nature of soil-borne pathogens like PC and their potentially devastating effects on processing vegetables provide a compelling argument for dedicated full-time attention and research.
“It can be devastating,” Tracey summed up, expressing the sincere desire more effective counter-measures existed for when PC rears its ugly head. “There is so much about this growers don’t have any control over - that just makes it that much harder.”
This season, let us point you in the right direction when it comes to proven protection from hazards like western bean cutworm, leafrollers, leafminers, aphids, cutworms, armyworms and more.
Get to where you want to go with insect control solutions from FMC.
58 days. Long, very straight high quality pods that are heavy set for excellent yield potential. Robust disease package for reliable performance.
Early. Bright, canary yellow fruit with an excellent smooth, blocky shape. Heavy fruit set and excellent quality helps increase yield potential.
Vigorous tops that hold up well under high disease pressure matched with an attractive globe with dark red color and good skin retention.
68-70 days, Very smooth root with a blunt tip. Ideal for waste reduction in processing. Widely adapted,