Disease Management

This section emphasizes the NOP requirements of IPM and contains general information on disease management strategies for organic growers.

See the Resources section for links to additional information.

As part of the organic certification process, organic producers develop an Integrated Pest Management (IPM) action plan (click here for the Organic System Plan website)  for managing existing and anticipated pests, including plant disease problems. This action plan must incorporate a range of strategies, from maintaining soil biodiversity and health to cultural and biological controls to sanitation. Only when these strategies are insufficient to maintain adequate plant health are approved chemical treatments allowed, and then only in conjunction with all the other practices outlined in the IPM plan. Organic pesticide use must follow all applicable federal and state laws, while also adhering to NOP standards.

The first step in effective disease management in organic farming is PREVENTION. By using a wide range of proactive strategies to reduce disease pressure and maintain plant health, you can reduce the incidence of disease and also increase the plant’s tolerance of some damage. If pesticide use is necessary, proper application timing is crucial to achieve maximum protection. Timing depends on both the disease cycle and local conditions.

IPM for plant disease

Good disease management begins with the identification of the potential problems that occur on crops in your area. Identification gives you information about the disease cycle and favorable conditions for disease development. This allows you to plan for disease prevention and implement appropriate management strategies before widespread damage occurs. While non-chemical methods are both required and the preferred approach in organic systems, pesticides may be used if they are part of your organic plan. Decisions to apply pesticides should also weigh ecological considerations, such as water and soil management and potential impact on beneficial organisms in the environment.

Remember that not all products are approved for use as organic pesticides, even if they bear the words natural, organic, or biopesticide on the label. Check with your organic certifier as well as your state Department of Agriculture to make sure you are using products properly.

A variety of materials are approved for the management of diseases. Several of these are traditional mineral-based materials, such as lime-sulfur, fixed coppers, and kaolin clay. Many plant extracts (neem, garlic, or soybean oils, for example) and biological pesticides (such as Bacillus products) are also allowed. Because of the vast range of pest-plant-pesticide combinations, we will not address specific management recommendations; however, links to further information are included at the end of this module.

While many of the materials approved for organic production are typically considered less hazardous than conventional pesticides, there are still some risks associated with their use. Some pesticides approved for organic production are actually more hazardous to handle and use than many conventional pesticides. Always read and follow pesticide label instructions, take care to minimize exposure and contact, and use appropriate personal protective equipment when using any pesticide.

Summary of best practices for organic disease management:

Know your crop and its potential problems, including significant disease problems. Understand the life cycle of the plant pathogen (disease-causing organism), including conditions that favor disease development, and effective prevention and management strategies. Use cultural strategies, such as disease-resistant plant material, crop rotation, crop diversity, and intercropping, sanitation, and other tools, to minimize pest problems. Maintain plant health using soil, water, and fertility management. Monitor your plants and scout for problems at appropriate times based on environmental conditions and the disease cycle. If necessary, a variety of pesticides are approved for disease management in organic systems; however, pesticides are only allowed if other methods are inadequate. Pesticides must be used in conjunction with cultural, mechanical, and biological prevention and control strategies.


Initial compilation courtesy of Lenora Jones

Washington State University Extension