During the winter the turf becomes weaker as the amount of carbohydrates within the plant becomes less and less. Snow moulds are among those disease types that are active and actually thrive under cooler temperatures and because of that they are the perfect opportunists when the turf is weaker to attack. The leaves of the plant will appear sunken and usually be coated in white mycelia after the pathogen has infected the plant.
Photo by William M. Brown Jr., Bugwood.org.
There are extra steps that we can take to help in hardening the plant off in the fall along with not neglecting regular cultural practices which will lead to optimal plant health the can help to lessen the effects of snow mould but usually it is still necessary to apply fungicides to prevent snow moulds. The good news is that there are many different fungicides available that will work very well to control snow mould.
There are many different types of fungi that cause snow moulds though so it is very important to know what type of snow mould you are trying to control when selecting fungicide products as some products will work better than others depending on which fungus is present. The two main diseases we deal with at snow mould time are grey snow mould and pink snow mould. Grey snow mould will typically have visible mycelia (white webbing) on top of the patch and the patches will be white or gray in colour. Pink snow mould will appear in similar sized patches and be pink to orange-brown in colour.
Different fungicide active ingredients will work and prevent the pathogen in different ways. Some will coat the plant tissue and prevent the pathogen from entering the plant, some fungicides will enter the plant foliage and spread throughout the leaf blade they were sprayed on and in that case prevent the disease from infecting the plant in the areas the active ingredient was sprayed on and some fungicides will enter the foliage and spread throughout the entire plant and in that case prevent the pathogen from infecting the plant structures it had spread to. The important factor with any of the active ingredients that do not just coat and remain on the plant tissue and instead move throughout the foliage is that you have to ensure that the plant is still actively growing (not dormant) enough for the product to be taken into the plant and then spread. Alternatively though, fungicide products that just coat the plant tissue will be less effective at times of aggressive plant growth and watering as the plant will grow out the active ingredient or the water will eventually wash it off in time.
At Target Specialty Products we have many different fungicide products available to treat snow moulds and the different disease types related to snow mould. FMC has a product called Disarm that contains the active ingredient Fluoxastrobin. Disarm is a systemic product that is labelled for control of and very effective with both grey and pink snow mould. Disarm is usually one of the products we have customers use as one of their September "clean-up" applications.
Quali-Pro has a three-way active ingredient fungicide product called Intaglio that contains the active ingredients Chlorothalonil, Fludioxonil and Iprodione. Intaglio is a very effective product and it is labelled for control of both grey and pink snow mould. Intaglio is the fungicide product that we have our customers use as their final fungicide application right prior to winter.
Quali-Pro also has single active ingredient products called Chlorothalonil 720F, Iprodione 240 SE and Propiconazole 14.3 ME which are also very effective for pink and grey snow mould. Those three Quali-Pro products are products that we would recommend to customers for use in September as one of their "clean-up" applications or as a preventative application first thing in the spring right after snow melt.
When used at the proper times in conjunction with strong plant health programs (fertility and cultural)Target Specialty Products fungicide products will be very effective in controlling all different types of snow moulds that exist.
