1. Control of Leaf Rusts • Scout regularly and remove infected plants or foliage • Remove weeds or alternate hosts • Water when leaves will dry quickly • Fungicides to reduce spread: myclobutanil (Systhane), propiconazole (Banner Maxx), azoxystrobin (Heritage), flutolanil (Contrast), chlorothalonil (Daconil), triadimefon (Strike), oxycarboxin (Plantvax)

2. Bacterial Leaf Spots • May not be visually distinguished from fungal leaf spots • More active in warmer temperatures than fungi • Common hosts: poinsettia, geranium, impatiens, ivy, mums, petunia, begonia

3. Bacterial Leaf Spots • Leaves have small, round, water-soaked lesions that turn brown • Water-soaked tissue looks greasy or oily, best seen on underside • Spots may have yellow halo • Center of lesion, tan with purple/red margin R. Lentini T Eaker

4. GW Moorman Bacterial Leaf Spots • Distinguish from fungal spots by: • Water-soaking • Look for fungal fruiting bodies in center of spots • Texture of the spots T. Eaker

5. Other Bacterial Diseases • Xanthomonas – Geranium • Erwinia soft rot – dahlia, begonia, primrose • Bad odor GW Moorman

6. Control of Bacterial Diseases • Good sanitation critical • Discard infected plants • Minimize overhead sprinkler irrigation • Chemical control rarely effective • Labeled for bacteria control: copper hydroxide (Kocide), copper sulfate pentahydrate (Phyton 27) and fosetyl-Al (Aliette)

7. Viruses • Most common in greenhouse • Impatiens Necrotic Spot Virus – INSV • Tomato Spotted Wilt Virus – TSWV • Spread primarily by Western flower thrips • Wide host range • Cucumber Mosaic Virus (CMV) • Vectored by aphids • Wide host range GA Salsbury

8. Impatiens Necrotic Spot Virus (INSV)

9. Tomato Spotted Wilt Virus (TSWV) Agdia Agdia

10. Other Viruses Agdia Agdia Tospovirus Ringspot virus Agdia Hosta X virus

11. Virus Management • Symptoms vary with host • Scout regularly and remove infected plants • Monitor and control thrips and aphids • Use caution in carry-over of plants • Quarantine new material (esp. vegetative material) • No chemical control available

12. Foliar Nematodes GW Moorman • Microscopic, parasitic, roundworms or eelworms • 250 susceptible crops • Begonia, African violets, mums, hosta, verbena, heuchera, helleborus and other perennials

13. Foliar Nematodes • Symptoms like bacterial leaf spots or downy mildew • To test: • Remove suspected leaf • Chop in water • View under scope (hand lens) for worm-like nematodes in the water

14. Control of Foliar Nematodes • Do not propagate infested material • Good sanitation • Keep foliage dry • Reduce plant to plant contact • Discard infested plants • No chemical controls available • Hot water dip may help, but plants may be injured by treatment

15. Disease Management • Verify your purchases are clean • Know your plant • Use resistant cultivars • Know what diseases to expect • History of greenhouse and crop • Know the diseases in your area • Learn about the diseases • Watch the weather • Know your control options