The Influence of Iron Sulfate Application Interval on the Suppression of Microdochium Patch on an Annual Bluegrass Research Green in Western Oregon

Core Ideas Two pounds of Iron sulfate heptahydrate per thousand square feet applied every two weeks suppresses Microdochium patch more consistently than a four week application interval and more effectively than a six or eight week interval at the peak of disease. Regardless of the iron sulfate application interval, the turfgrass quality was considered unacceptable because of either a lack of complete disease control or turfgrass thinning caused by the iron sulfate treatments. Future research will be necessary to determine if it is possible to move away from a calendar based spray schedule by developing a weather based application model.