IPM Strategies to Manage Plant Diseases
Exclusion — keep pathogens (things that cause disease), vectors (things that spread disease) and infected plants out of disease-free areas.
Eradication — destroy a disease organism after it has become established. You can do this by destruction of infected plants, disinfection of storage bins, containers and equipment, and/or soil disinfection by fumigation, pasteurization, solarization or drenching.
Protection – use a physical barrier such as a row cover. You can also use chemical applications available to prevent a disease from becoming established.
Resistance — plant resistant varieties.
Therapy – use chemicals that are systemic in the plant.
Avoidance – use good cultural practices such as planting date selection, seedbed preparation and water management to avoid disease. Poorly drained soils, shade and other factors can increase the susceptibility of plants to disease. Provide adequate irrigation, fertilization and space for each plant. Handle plants carefully to prevent injury, as the injury may later be the access point for a disease.
Fireblight on pear can be managed using a combination of IPM strategies.
Compost teas are actively brewed to produce beneficial microbes. See Notes on Compost Tea, National Sustainable Agriculture Information Service
Tomato Spotted Wilt Virus has increasingly been found in home gardens. See Greenhouse Plant Viruses (TSWV/INSV) .
Soil solarization is a nonchemical method for controlling soil borne fungal diseases and nematodes, during hot summer months.
Winter damage to conifers — a video from the CSU Plant Diagnostic Clinic
IPM Strategies for Crops
- Use clean seed and vegetative propagating material. Some disease-causing organisms are seed-borne and others are associated with seeds.
- Select cultivars that are resistant or tolerant to pathogens.
- Destroy or remove infected crop residues, culled fruits or prunings. Crop residues, which may be reservoirs of disease organisms, can be burned, composted, buried or shredded.
- Rotate crops to avoid or reduce the build-up of disease organisms in a field. Note that some plants have shown to have a suppressive effect on diseases.
- Provide plants with good nutrition. A properly nourished plant can withstand or tolerate the attack of plant pathogens better than a stressed plant.
- Avoid injuring or bruising plants because many pathogens can enter a plant through an injury or wound.
- Use proper spacing to allow air movement between plants and reduce the amount of time that leaves are wet.
- Schedule timing and duration of irrigation to satisfy the crop requirements without over-watering. Too much water can be as detrimental as not enough.
- Select the appropriate control method — biocontrol or chemicals (fungicides, bactericides, fumigants and nematicides).
IPM Strategies in Forests & Range
Plant pathogens can cause mortality of individual plants as well as shifts in the composition of plant communities. At the same time, pathogens can help maintain plant species diversity.
Will the condition actually harm the tree, shrub or grass plant? Is it likely to cause economic or aesthetic damage? There are instances where a condition can run its course without assistance or with some minimal attention including pruning, fertilization or site amendments.
Review all available control methods and follow all local, state and federal regulations that apply. Evaluate the benefits and risks of each treatment and choose the best solution with the least negative environmental impact. The challenge, when using pesticides, is to pick the one that will cause the least harm to non-target organisms in the forest or landscape.
The Field Guide to the Insects and Diseases of the Rocky Mountain Region from the U. S. Forest Service is a complete resource of pests found in the region.
Nematodes: Alternative Controls, National Sustainable Agriculture Information Service
Notes on Compost Tea, National Sustainable Agriculture Information Service
Sustainable Management of Soil-borne Plant Diseases, National Sustainable Agriculture Information Service
Use of Baking Soda as a Fungicide, National Sustainable Agriculture Information Service