Year after year, farmers across Ontario swap stories of yield losses from white mould – Sclerotinia –and as its impact and incidence spreads, so does the need for proactive protection.
“Growers in Eastern Canada have been battling white mould for more than 25 years,” says Marc Maisonneuve, Retail Territory Manager with Corteva Agriscience™. “The problem is, this disease has become more detrimental as soybean yields have increased, and effective fungicide options have been limited.”
Premium white mould protection for 2023
Marc Maisonneuve, Retail Territory Manager Corteva AgriscienceWhite mould can slash yields from 10 to 20 per cent in a moderate infection or in severe cases 10 to 20 bushels per acre. While every grower has their individual threshold for yield loss, Maisonneuve notes that soybeans are experiencing some of the strongest market prices in decades, making investment in disease protection and management more important than ever.
Fortunately, he said Corteva has good news this year for soybean farmers with a new option for white mould protection: Viatude™ fungicide with Onmira™ active. This unique fungicide deploys two highly effective active ingredients to protect soybeans.
“This new product will be a game-changer for white mould disease protection and resistance management,” says Kirsten Ratzlaff, Portfolio Marketing Manager with Corteva Agriscience.
Viatude is a high-level protection tool that can easily be integrated into any soybean management system early to combat disease and offer peace of mind.
Plan for prevention
“To avoid any unpleasant surprises at harvest time, farmers need to take a proactive prevention approach to white mould,” Maisonneuve advises. “The disease itself is hard to identify as the soybean plant grows, so if you don’t manage it, you may be setting yourself up for disappointing yields.”
White mould infection typically occurs during the four-week flowering period in soybeans. That means July is peak season for the disease across Ontario and Quebec. Humid conditions, especially in lower parts of the plant canopy are ideal for infection. Spores develop on the flower petals then fall, invading the stem and spreading the infection where it chokes off the plant’s vital water and nutrients.
“That’s where the yield robbing take place,” Maisonneuve explains.
The spores are hard to see and once farmers start to notice effects from the disease, it’s too late. Once a soybean plant is infected, the full impact of the infection won’t be obvious until a few weeks before harvest, or towards the end of a plant’s full maturity.
Until now, soybean farmers have had limited tools when it comes to products to combat white mould disease. It’s critical that each active ingredient provides protection to achieve true resistance management. Viatude contains two highly effective active ingredients that provide multiple effective modes of action to combat white mould and reduce the risk of the developing resistance in the disease.
“This unique combination contains one of the strongest actives on white mould, Onmira, delivering industry leading protection and return on investment,” Ratzlaff explains.
Approach fungicide application as insurance
Kirsten Ratzlaff, Portfolio Marketing Manager, Corteva Agriscience“Even with disease management practices like crop rotation and diligent scouting, field history takes precedence over everything else when it comes to white mould infections,” Maisonneuve says, explaining that disease spores can live in crop debris for up to 10 years. “If a field has been infected in the past, it should now be considered a high risk.”
Many farmers watch the weather, preferring to scout once damp or humid weather sets in, but Maisonneuve explains that weather conditions don’t really matter. For example, the 2022 Ontario soybean growing season saw hot, dry weather conditions. While last year saw lower white mould infection rates, the weather only served to delay the infection period.
The best strategy? Plan ahead and have a prevention plan. Because white mould is so hard to predict and identify, include a fungicide treatment as part of a disease risk management strategy. As to timing, aim to protect as many flower petals from infected spores as possible. Maisonneuve says the R1 ½ to R2 stage is the ideal time to apply fungicide to achieve the best results in terms of systemic movement and coverage of the active ingredients within and on the plants for optimal protection within a dense soybean canopy. He also notes some fields may need two applications, depending on the host and infection rates.
“Because white mould is so hard to predict, a fungicide application, like Viatude, acts as insurance against yield loss,” Ratzlaff says. “Adding an application to your soybean management helps to protect a grower’s yield potential and bottom line.”
For more information about Viatude, visit viatude.corteva.ca.
