Fighting Sclerotinia with Fungicides

July 9, 2020

As flowering begins in soybean fields, it’s time to apply a fungicide proactively to protect the quality of your soybean plants and potential yield. In Quebec and Ontario, sclerotinia (or white mould) is the most common disease among soybean plants, and it also causes the most economic damage. Whether it comes from your machinery, poorly composted manure, animals or a previous year’s infestation, Sclerotinia can be stubborn! In this article, we’ll go over the benefits of using fungicides to reduce any negative economic impacts.

The sclerotinia cycle

First, you need to understand that sclerotia are the dormant resting bodies of fungi. They hibernate in the soil and can live for 7 years, with a strong fungal structure that can withstand freezing and thawing. In the spring, sclerotia germinate in the top centimetre of the soil and propagate spores that can contaminate flowers. That’s how white mould appears on plants and weakens stems. Contaminated plants then produce sclerotia that increase the quantity of spores in the soil.

Favourable management conditions

Unfortunately, the recommended conditions to increase soybean yields are also favourable to Sclerotinia! Fertile soil, early seeding, narrow rows, high populations and high-yield varieties with branches are all factors that contribute to Sclerotinia. Cool and humid conditions can also increase the risk of infection and disease.

Reducing sclerotinia’s impact

Of course, fungicides can help control sclerotinia. But this is a preventive measure, not a treatment. To eliminate seasonal Sclerotinia, we recommend spraying twice at the R1 and R3 stages to maximize the effect of the fungicide. You can also give your crops the best possible odds by:

  • Using resistant varietie;
  • Using varieties with good standability;
  • Opting for a longer rotation with a non-host crop;
  • Favor wider rows for improved aeration;
  • Managing crop waste;
  • Using certified and treated seeds.

Your trusted Prograin representative can help you implement a monitoring system and apply recommendations to fight Sclerotinia. Give them a call!