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Similar to Cfsa cucurbits and tomatoes 2012
Cfsa cucurbits and tomatoes 2012
- 1. Carolina Farm StewardshipAssociation 2012 Sustainable Agriculture Conference Sustainable and Organic Approaches To Managing Cucurbit and Tomato Diseases Anthony (Tony) Keinath Vegetable Pathologist Clemson University Coastal REC Charleston, SC
- 2. Today’s Outline Intro to Tomato and Cucurbit Diseases Important Pathogens Risks to Other Crops 5 General Control Strategies Avoidance Eradication Recommendations for Specific Diseases “More of what works, less of what doesn’t”
- 3. Avoid extremes “You can’tgrow organic vegetables in the Southeast.” “All diseases can be managed organically.”
- 4. Symptoms of ImportantTomato Diseases--Root Disease Leaves Stem Crown Roots Fruit Bacterial wilt ** ** * * -- Southern -- -- ** * (*) blight Fusarium wilt ** * -- (*) -- Root knot -- -- -- ** --
- 5. Spread and Survivalof Important Tomato Pathogens--Root Spread Rain Survive in Disease Organism Wind Splash Water Soil Bacterial Bacterium -- -- ** ** wilt Southern Fungus -- -- -- ** blight Fusarium Fungus -- -- -- ** wilt Root knot Nematode -- -- -- **
- 6. Host Range ofImportant Tomato Diseases--Root Other Other Br-Lf Disease Pepper Eggplant Potato Cucurbits Veg. Crops Weeds Bacterial ** ** * -- -- tobacco * wilt geranium Fusarium -- -- -- -- -- -- -- wilt Southern ** ** (*) (*) beans, (*) blight sun peanut choke Root knot ** ** ** ** *** ** *
- 7. Symptoms of ImportantTomato Diseases--Foliar Disease Leaves Stem Crown Roots Fruit Bacterial speck/spot ** (*) -- -- * Gray leaf spot ** -- -- -- -- Early blight ** * -- -- * Late blight ** * -- -- ** Spotted wilt ** * -- -- **
- 8. Spread and Survivalof Important Tomato Pathogens--Foliar Survive in Disease Organism Wind Rain Splash Water Soil Bacterial Bacterium * ** -- * speck/spot Gray leaf Fungus ** ** spot Early blight Fungus * * -- * Late blight Water ** * -- (*) mold Spotted wilt Virus -- -- -- --
- 9. Host Range ofImportant Tomato Diseases--Foliar Other Other Br-Lf Disease Pepper Eggplant Potato Cucurbits Veg. Crops Weeds Bacterial ** -- -- -- -- -- -- speck/spot (spot) Gray leaf ** (*) -- -- -- -- * spot Early blight -- (*) ** -- -- -- (*) Late blight -- -- ** -- -- petunia * Spotted wilt ** -- * -- -- peanut ** tobacco
- 10. The Disease Triangle AnAid to Management Host Plant Disease Environment Pathogen
- 11. The Disease Trianglefor Gummy Stem Blight Watermelon Didymella Environment
- 12. Host Range ofImportant Cucurbit Diseases Winter Summer Squash/ Cuke Melon Watermelon Squash Pumpkin Gourds Downy ** ** * * ** * mildew Phytophthora * -- ** ** ** * Powdery ? * ** ** * * mildew Gummy * ** ** -- * * stem blight Anthracnose ** (*) * -- * **
- 13. Symptoms of ImportantCucurbit Diseases Disease Leaves Crown Vine Fruit Downy mildew √ Powdery mildew √ Phytophthora crown √ √ √ √ and fruit rot Gummy stem blight √ √ (√) √ and black rot Anthracnose √ √ √
- 14. Spread and Survivalof Important Cucurbit Pathogens Spread Rain Survive Disease Organism Wind Splash Water in Soil Downy mildew Water Mold ** (*) -- -- Powdery mildew Fungus ** -- -- -- Phytophthora Water Mold crown and fruit -- * ** ** rot Gummy stem blight and black Fungus * ** -- * rot Anthracnose Fungus (*) ** -- *
- 15. Diseases that AffectBoth Cucurbit and Tomato Crops Phytophthora Southern blight crown and fruit rot Tomato, pepper, Pepper, tomato, eggplant eggplant Snap bean Snap and lima Jerusalem artichoke beans Peanut Root knot Many broad-leaved crops
- 16. 5 General Control Strategies Avoidance Protection Resistance Eradication Exclusion
- 17. Challenges with Sprayingfor Organic Disease Control (Protection) Favorable environment Biopesticides usually less effective than conventional fungicides Powdery mildew is exception NOP allows S and Cu only as a last resort Protectants only Labels of biopesticides are inaccurate
- 18. What is AVOIDANCE? Preventing contact between pathogen and host to prevent disease. Modifying the environment to make it less favorable for disease. One of 2 main strategies for organic disease control. Warning: pathogen is still present!
- 19. Avoidance Techniques Change planting date Raise beds to prevent damping-off Avoid wetting leaves when watering Mulch to prevent fruit rots
- 20. Eradication: Length ofCrop Rotations Foliar pathogens Soilborne pathogens No long-term survival Various survival structures structures Until infested debris is Sclerotia gone Oospores ≤ 1 yr for bacteria Dormant mycelia 1-3 yr for fungi and Cannot eradicate with water molds rotation Can reduce populations (= primary inoculum)
- 21. 2 Crop Rotationand Planting Schemes for Small Acreages For foliar diseases: For root and wilt Spread crops in diseases: same botanical Group crops in family far apart same botanical Slows pathogen family together spread Rotate away for 3-4 Disadvantage: Makes years crop rotation difficult Disadvantage: May increase foliar diseases in wet years
- 22. Foliar Soilborne pathogens pathogens Separate or Group Related Tomato Solanaceous Squash Arugula Cucurbits Eggplant Crops? & Broccoli Cukes Pepper Brassicas
- 23. Soil Solarization Sterilizing soil by using heat from the sun trapped under clear plastic by the “greenhouse effect” Solarize Solarizing soil potting is PARTIALLY soil in effective clear plastic bags 2 wk 8 Use 2 weeks layers in plastic June- July
- 24. Composting to Eliminate Pathogens Eradication of Nematodes Fungi Seeds pathogens in plant 180 debris 160 D To be safe: e 140 Peak temperatures g 120 147-158 F. for 21 r 100 days e 80 e Difficult to achieve s 60 in 1-cu-ft pile 40 Survived: F 20 Fusarium wilt of tomato 0
- 25. General Cultural Practicesto Avoid Disease on All Crops Reduce leaf wetness •Drip irrigation •Increase row/plant spacing •Avoid edges of woods •Row orientation Improve soil drainage • Raised beds • Add organic matter • Compost • Cover crops
- 26. Controlling Vegetable Diseases- GeneralOrganic Techniques Bacteria Fungi (true) Reduce leaf wetness Copper does not work One- to two-year Sulfur is better option rotation Water molds Copper (oomycetes) Root diseases and Copper nematodes Potassium phosphite Improve soil drainage Not organic certified Increase organic matter Resistance
- 27. General Cultural Practicesto Manage Tomato Diseases Grafting •Root knot •Southern blight •Fusarium wilt •Bacterial wilt •(awaytogarden.com) High Tunnels • Prevent fruit cracking • Reduce foliar disease • Extend season • (hightunnel.org, Kansas State)
- 28. Resistant Tomato Varieties ResistanceAvailable No Resistance Spotted wilt Bacterial spot Early blight Bacterial wilt Root knot Southern blight Late blight ‘Mountain Magic’ (campari type) Resistance in All ‘Plum Regal’ Hybrids Gray leaf spot Fusarium wilt Except grapes
- 29. Gray Leaf Spot ‘Cherokee Purple’ is v. susceptible 2-3 year rotation Avoid planting tomato and pepper next to each other Early planting Disease is favored by high temp and humidity
- 30. Phytophthora crown andfruit rot
- 31. Phytophthora capsici Sporangia— Oospore— • Form on infected plants • Forms in/on fruit • Spread by/in water • Survives in soil
- 32. Controlling Phytophthora crown andfruit rot— Water management Raised beds • Cut water furrows • Don’t punch holes too deeply Do not use surface water Drip irrigation Avoid planting low areas
- 33. Controlling Phytophthora crown andfruit rot— Soil management Mulch--Plastic or organic Wash equipment • Between fields • Newly purchased or borrowed Remove cull fruit
- 34.
- 35. Controlling Cucurbit Downy Mildew Copper sprays • On crops other than cucumber Avoidance • Early planting date Resistance • C. maxima • Cucumber cultivars • Tolerant • ‘Aladdin’ pumpkin • Some summer squash cv.
- 36.
- 37. Controlling Cucurbit Powdery Mildew Biopesticides—spray top and bottom of leaves • Organocide (fish oil + sesame oil) • Potassium bicarbonate • JMS Stylet Oil or horticultural oil Sulfur • Do not apply at 90ºF Resistant summer and winter squash and pumpkin cultivars from Harris Seeds
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- 40. Survival of theGSB Fungus in Cantaloupe Crowns Nov 05 May 06 Nov 06 May 07 Nov 07 100 % Crowns with viable D. bryoniae Soil surface % Crowns with viable D. bryoniae 90 Plastic mulch 100 Soil surface 80 Buried 5 in. 90 Plastic mulch 80 70 70 60 60 50 50 40 40 30 30 20 20 10 10 0 0 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 Weeks after burial Weeks after burial
- 41. Controlling Gummy StemBlight and Anthracnose Rotate for 3 years • Summer squash in 2nd or 3rd year Plant early Disease-free transplants Do not reuse plastic mulch Disk fields to bury debris as soon as possible after harvest
- 42. Managing Fusarium Wiltof Watermelon Resistant cultivars Only resist. to race 1 Grafting onto bottlegourd or hybrid squash Both are susceptible to root knot Crop rotation to Hairy vetch as winter reduce build-up of cover crop/green pathogen manure Works best before soil is infested
- 43. Managing Bacterial Fruit Blotch See conventional guidelines Only exception is avoid use of Actigard
- 44. Managing Cucurbit Viruses Spreadby Aphids Resistant cultivars Check if conventional or GM Horticultural oil sprays Every other day Prevent infection Camouflage Rye grass between rows Kaolin clay sprays
- 45. Sustainable Disease Management Organic soil Cultural management practices Check plants • Cover crops • Exclude, weekly for • Crop rotation • Eliminate and problems • Compost • Avoid disease Identify diseases to Apply select the best biopesticides control method preventatively •Bacterium or fungus? •Water mold or true fungus?