Preventative fungicide applications are only necessary in sports turf, where perfect conditions are needed, and there is the financial reason to keep the turf playable. In general, purely preventative applications in ornamental turf is a huckster's agenda. Of course if one's business is built on profiting by churning sales of pesticides, then one would push such an agenda. The responsible ornamental turf manager would have nothing to do with this idea.
Application of a fungicide may control the targeted pest, but it is not known how many other non-destructive, and even beneficial, organisms are also damaged or destroyed by the fungicide. There have been cases on golf courses of fungicide controls for one harmful species reducing the fungus population in general so that a more harmful variety of fungus can proliferate.
Better course is to assist and educate so that proper cultural practices are followed in ornamental turf management. "Success with a landscape is 99% cultural practices."
North central Indiana
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