1. Diseases
Help me! I’m dying.

2. Disease
Disease is a plant disorder caused by an infectious pathogen or agent

3. Three Conditions Necessary for Diseases
Host plant
Disease causing organism or pathogen must be present
Favorable environment for disease organism to develop

4. Groups of pathogens Bacteria Fungi Viruses
Parasitic plants- mistletoe, dodder, lichens (attach to plants)

5. 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

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

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

8. Blight- Bacteria and Fungi
Cause plant to quickly turn brown or black as if they had been burned
One specific blight is fire blight-devastating apple crops

9. Canker-Bacteria and Fungi
Causes open wounds on woody plant stems

10. Damping off- Fungi Fungal disease
Causes young plants and seedling to rot off at soil level

11. Galls- Bacteria and Fungi
Round swelling or growths on plants
Usually caused by an insect that vectors the disease

12. Leaf spot- Bacteria and Fungi
Rings of different shades of brown, green, or yellow
Looks like dots or circles

13. Mildew Grows on leaf surfaces Upper and lower leaves
Appears as white, gray or purple spots
Example is powdery mildew

14. Mosaic- Virus Caused by a virus
Leaves have irregular mottled areas with patterns
Ranges from dark green to light green to yellow to white

15. Tobacco Mosaic Virus (TMV)
This is a nasty virus
Transmitted by smokers from tobacco to tomato (most often)
Another reason not to smoke, y’all!

16. Rots- Fungi
Causes plants to decay and die
Usually has a unique smell

17. Rust- Fungi Causes small spots on leaves
Resembles yellow, orange, brown or red rust
Mainly on underneath of leaf

18. Smut- Fungi Black powdery disease Causes blisters that burst open
Releases black spores
Grows on aphid’s honeydew

19. Wilt- Fungi and Bacteria
Disease that blocks the uptake of water in plants stems
Causes plants to look constantly wilted even when adequately watered

20. Parasitic Plants Lichen Dodder Mistletoe
Roots into plant and uses its sugars and starves or chokes out host plant

21. Disease Treatment Fungus? Use a fungicide
Use resistant cultivars when available for virus and wilt resistance
Cut out diseased portions with sterile equipment

22. Disease Treatment 4. Keep it clean 5. Reduce humidity and warmth
6. Control insects that spread disease
7. Quarantine infected plants

23. Disease Treatment Remove dead plant material from area
Promote ventilation and air circulation
Prevent disease, it’s easier than treating!