A fungicide’s ability to infiltrate the soil profile dictates how effective it is against soil-borne fungal pathogens. On greens and tees, properly managing thatch and using soil surfactants can help enhance the efficacy of your program by encouraging better mobility.
Thatch Management
Not staying on top of thatch management can cause fungicides to tie up on the carbon-based portions of organic material. It can also make the soil hydrophobic to a degree due to the plant materials’ decaying sterols.
As long as you are performing your cultural practices (aeration, verticutting, and topdressing), you are allowing good water and gas exchange through the soil profile and will not have to deal with any of the previously mentioned issues.
This will allow you to spray and water your fungicides into the root zone to combat root-type and other pathogens without product binding on the thatch and getting stuck there.
Using Soil Surfactants
Using a penetrant-type soil surfactant will aid in breaking through the surface tension at the top of the soil profile and thatch. This will allow for easier water infiltration.
Superintendents typically use a higher rate of carrier for soil-focused sprays. This higher volume of water is run through the sprayer so that you don’t need as much irrigation water later.
With this type of spray, it’s best to aim for at least 1/10 to 1/4 of an inch of irrigation following your application. This should be done immediately, or by that evening at the very latest, so the product doesn’t have a chance to bind up on something.
1/10 to 1/4 of an inch of irrigation is generally good enough because most of your turfgrass roots are in the top inch of soil. The roots will pick up the product, then the crown, and it will continue to move upward and protect the plant from the roots up.
For additional fungicide tips and advice tailored to your course’s needs, reach out to your ATS representative.
