Diseases

1. Diseases Help me! I’m dying.

2. Disease • Disease is a plant disorder caused by an infectious pathogen or agent Host – Plant the disease attacks Pathogen – Any disease causing agent Environment – moisture and temperature needed for the pathogen to grow

3. Bacteria Single-celled organism Must remain in host or under debris Actively divide to spread Fungi Multi-cellular Eats on plants and hurts them in the process Produces spores that spread Viruses Ultramicroscopic parisites Attack plant tissues Should destroy plant completely if found Parasitic plants- A plant that attaches to another plant Ex. mistletoe, dodder, lichens Groups of pathogens

4. Plant Disease • Must be identified before they can be treated • Warm temperatures and moist conditions in greenhouse plant production make most horticulture plant diseases worse

5. Disease • Preventing plant disease through sanitation and insect control is much easier than treating the disease.

6. Blight Canker sores Damping off Galls Leaf spot Mildew Mosaic Rots Rust Smut Wilt Diseases

7. Blight • Infectious bacterium • Cause plant to quickly turn brown or black as if they had been burned • One specific blight is fire blight-devastating apple crops • Prune 6-8” below infection

8. Canker • Bacterial disease • Causes open wounds on woody plant stems

9. Damping off • Fungal disease • Causes young plants and seedling to rot off at soil level • Need clean containers and soil and plenty of air circulation between plants

10. Galls • Round swelling or growths on plants • Usually caused by an insect that vectors the disease

11. Leaf spot • Rings of different shades of brown, green, or yellow • Looks like dots or circles

12. Mildew • Fungus • Grows on leaf surfaces • Appears as white, gray or purple spots • Example is powdery mildew • Homemade remedy= 2 tsp baking soda + horticultural oil with 1 gal water

13. Mosaic • Caused by a virus • Leaves have irregular mottled areas with patterns • Ranges from dark green to light green to yellow to white • Tomato mosaic virus is common in tomatoes

14. Rots • Fungus • Causes plants to decay and die • Usually has a unique smell • Improve drainage for the plant to prevent

15. Rust • Fungus • Causes small spots on leaves • Resembles yellow, orange, brown or red rust • Mainly on underneath of leaf

16. Smut • Black powdery disease • Causes blisters that burst open • Releases black spores • Grows on aphid’s honeydew

17. Wilt • Fungus • Disease that blocks the uptake of water in plants stems • Causes plants to look constantly wilted even when adequately watered