A preventive fungicide applications not only inhibits fall infection, but it also suppresses or delays disease development in the spring. This disease can continue to damage shoots even after the zoysia has entered fall dormancy provided that air temperatures remain relatively warm. This is very common in our area. Therefore, you are not out of the woods if you don't notice any symptoms before the turf goes dormant. The damage caused by the fungus after turf dormancy will be apparent next spring during green-up and by that time it is too late to do anything about it.
Curative treatments are much less effective in controlling large patch.
Many zoysia shoots are damaged by the time fungicides are applied. Because of cool temperatures in fall and spring, the turfgrass cannot quickly recover from the injury. Nevertheless, curative treatments of iprodione, chlorothalonil and possibly flutolanil may prevent patches from further expanding during favorable weather.