Pythium Aphanidermatum - Management

Management

Several cultural management methods can be effective in avoiding disease caused by Phythium aphanidermatum. The pathogen thrives in a moist environment, so it is important to prevent an excessive amount of moisture from building up in the plant media. Irrigation that is too frequent and usage of soil that has poor drainage are common mistakes that result in inoculation. In addition, poor ventilation and insufficient exposure to sunlight can cause the plants themselves to accumulate moisture, potentially spreading disease. Sanitation of the soil using chemical treatment and minimizing the amount of plant debris in which the pathogen can survive is also an effective cultural practice. Fungicides are also effective control methods. Systemic and contact fungicides can be used, but in order to prevent the pathogen from becoming resistant to the treatment it is best to alternate between systemic and contact substances. Several chemical types can be used to manage the pathogen including acylalanines, thiadiazoles, carbamates, cinnamic acid derivatives, phosphonates, and phosphites. Rotation of chemical type is important in preventing resistance of the pathogen (5). In general, these fungicides yield best results when used for preventative purposes. Biological control of the pathogen has also been successful. Bacteria and fungi can be used to treat Pythium aphanidermatum in turf, crops, and flowering greenhouse plants. Bacteria species include Bacillus subtilis, Candida oleophila, Enterobacter cloaceae, and Pseudomonas species. Fungi include many Trichoderma species, namely T. harziamum, T. virens, and T. hamatum.