2. I. Introduction to disease control A. Causes of Plant Diseases 1. Abiotic a. Non-living cause of a plant disease by a physical or chemical component of the environment that is harmful to plant growth b. By definition, abiotic diseases cannot spread from plant to plant c. Abiotic plant diseases could include: Temperature extremes - winter kill, frost damage Soil moisture extremes Soil nutrient deficiencies or imbalance Agricultural chemicals Lightning, hail, wind, or pollutants

3. I. Introduction to disease control A. Causes of Plant Diseases 1. Biotic a. Living cause of a plant disease by a pathogen - any living organism capable of causing disease in a particular host species b. Most biotic pathogens are parasites, which grow and reproduce only on living plant tissues c. Major groups of plant pathogens could include: Fungi Bacteria Mycoplasmalike organisms Viruses Nematodes

4. I. Introduction to disease control B. The disease triangle 1. Host plant a. Type of grass or grasses that are affected by this Disease (pathogen) b. This is sometimes different within grass species - different cultivars of the same species might have different degrees of susceptibility

5. I. Introduction to disease control B. The disease triangle 2. Pathogen a. The disease causing organism b. This could be a fungus, bacteria, virus, or non-living agent. Parasitic or non-parasitic pathogen

6. I. Introduction to disease control B. The disease triangle 3. Environment a. Environmental conditions that favor the development of the disease b. These conditions might include temperature, humidity, wind (or lack there of), time of the year, and moisture content (either in the air or in the plant)

7. Locations for Testings For times and locations for testing to obtain a Applicators License, call your local Community College, or the Department of Agriculture in your state. Clackamas Community College: 503-657-6958 ex.2269 Mount Hood Community College: 503-491-7592 Portland Community College: 503-614-7289 Chemeketa Community College: 503-399-6556 ODA: 503-986-4635

8. Suggested Guidelines for Maintenance Staff 2. Know and understand what healthy turf looks like 3. Report anything that looks different than healthy turf 4. Ask questions 5. Invest in a good pocket magnifying glass 1. Be observant 6. Take the Turf Management Program at Walla Community College

9. Questions?