WI Pesticide Applicator Test Correct 100%

Define plant disease and what causes disease. - ANSWER Plant disease is any harmful change in the physiology and/or structure of a plant caused by the continuous irritation of a primary causal agent (pathogen). List examples of plant pathogens. - ANSWER 1. Fungi 2. Oomycetes 3. Nematodes 4. Bacteria 5. Viruses 6. Phytoplasmas 7. Viroids How is fungi spread? - ANSWER Wind, rain splash, or insect vectors How is Oomycetes spread? - ANSWER Wind, rain splash, Transfer of infested soil (for example on equipment tires) How is Bacteria spread? - ANSWER Rain splash, insect vectors, and on tools How is Phytoplasmas spread? - ANSWER Only by insect vectors (principally leafhoppers) How are Viruses spread? - ANSWER Insect vectors, mechanical transmission (rubbing of infected leaf onto another leaf by equipment), some are seed borne, vegetative propagation. How are Viroids spread? - ANSWER mechanical transmission, vegetati