Avoid frequent sprinkling because this generally keeps surface soil too moist and promotes fungal growth. Damping-off may not occur at a location for many years and then be devastating in one season. Such situations sometimes can be traced to a change in crops or plant varieties, a change of source of soil, or some change in cultural practice. Prior to initiating any changes, it would be wise to test the intended changes on a small scale before the main planting is done. Control measures for damping-off fall into several categories depending on the facilities available and whether preventive measures are to be used after the trouble has begun.
Preventive measures are much preferred, but make preparations for emergencies.
Preventive measures are based on eliminating fungi that cause damping-off or providing chemical barriers to prevent the fungi from growing in the planting medium. Pasteurization of Soils Soil for growing transplants in flats can be steam pasteurized. If steam is used, the entire soil mass should be maintained at a temperature of 160 degrees F for 30 minutes. To prevent soil recontamination, all items such as tools, pots, and flats, etc., must be clean. It is important to use fresh chlorine bleach-water solutions.