Most of the important diseases in lawns are caused by fungi. Disease occurs when the fungal pathogen is present, the environment is favorable for infection to take place, and the host (the plant) is susceptible. Control or management of disease is obtained by breaking the interaction of host, pathogen, and the environment. This approach is integrated disease management. Multiple tactics are used to obtain integrated disease management.
The host can be manipulated by using a turf grass or plant that is adapted to the site conditions. Use of good cultural practices that encourage plant rigor also allow the plant to resist infections or to recover from disease faster. Certain varieties of a particular grass or plant may have resistance to common pathogens or be particularly well adapted to the environment. Sometimes it may be necessary to prevent or cure an infection or disease spread by use of fungicides (Preventive and Curative treatment). Most of these fungicides work by protecting the uninfected turf or plant, thereby allowing healthy turf or plants to persist.
Periods of high humidity, over irrigation, rain, heavy dews or fog will favor the development of fungal disease in turf or plants. Prolonged presence of moisture is needed on the plant surface. Other factors that can influence disease are improper mowing practices, and improper irrigation practices. Over watering or watering in the later afternoon or night can make the plant more susceptible to disease outbreak.