As with any fungicide application, the duration of control is governed by a number of factors, including application accuracy, disease pressure, weather conditions before or after application, cutting regime, pathogen to be treated etc..Remember that in very high pressure situations, if the diseaseis already established in the turf at application, it may be that the disease gets visibly worse after treatment, as it will be too far through its life cycle. The pathogen will then express itself before the chemical treatment can get a level of control.