Identifying Virus and Bacterial  Diseases in High Tunnels       Michelle Grabowski
What’s Different and Why?•     High tunnels provide a unique environment•     Excess heat and humidity•     Plants are han...
Viruses
Tobacco Mosaic Virus (TMV)                                                                                                ...
Tobacco Mosaic Virus(TMV)•     Fruit Symptoms                                                            S.M. Douglas, CTA...
Tobacco Mosaic Virus• Infects over 150 genera         – petunia, pepper, weeds• Can come in on seed coat• Very durable    ...
Tomato Spotted Wilt Virus(TSWV)• Bronzing of leaves• Small darks spots  on leaves, streaks  on petioles & stems© 2011 Rege...
Tomato Spotted Wilt Virus(TSWV)© 2011 Regents of the University of Minnesota. All rights reserved.
Tomato Spotted WiltVirus (TSWV)• Early infection  results in no fruit• Later infection         – Ring spots on green      ...
TSWV• Infects 300 species in 34 families                                         P.M.J. Ramakers, APS Bugwood.org• Can spr...
Identifying Virus Diseases withImmuno Strips•     Agdia.com•     5 for $32-37•     25 for $105-120•     Strips for many vi...
UMN Plant Disease                                    Diagnostic Clinic• Will identify the problem  regardless what it is• ...
Managing Virus Diseases in Tunnels• Purchase seed from a reputable supplier  that uses and acid treatment of seed• Purchas...
Managing Virus Diseases in Tunnels• Do not grow ornamentals with tomatoes and  other crops• Control weeds in tunnels• Main...
Managing Virus Diseases in Tunnels• Workers must have clean clothing and wash hands  before entering the house• Wash hands...
Sterilizing Equipment & Hands• Soap and water• Carnation instant nonfat dry milk  (20% wt/vol)• 1:10 bleach water solution...
Bacteria
Tomato Pith NecrosisPseudomonas corrugata      Photos from M. McGrath, Long Island Hort. Research & Extension Center© 2011...
Pith Necrosis   P. corrugata                                                                         M. McGrath, Long Isla...
Tomato Pith NecrosisPseudomonas corrugata• Favored by high humidity, cloudy  weather, high N, rapid growth• Soil borne, po...
Managing Pit Necrosis• Reduce humidity through ventilation• Provide adequate but not excessive fertilizer• Remove entire p...
Bacterial CankerClavibacter michiganensis subsp. michiganensis• In field conditions or with  overhead irrigation see• Bird...
Bacterial CankerC. michiganensis ssp. michiganensis                                                    MSU© 2011 Regents o...
Bacterial CankerC. michiganensis ssp. michiganensis• Lives on surface of the seed & inside seed coat• Survives 5 yrs on se...
Bacterial CankerC. michiganensis ssp. michiganensis• Enter through wounds or stomata• Spread on workers hands, clothing, t...
Managing Bacterial Canker• Use certified disease free seed or treat seed in hot  water for 25 min. at 125F• Reduce overhea...
Managing Bacterial Canker• Immediately bag and remove infected plants• Remove several neighboring plants as well• Do not l...
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Virus and bacteria in High Tunnels

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Virus and bacteria in High Tunnels

  1. 1. Identifying Virus and Bacterial Diseases in High Tunnels Michelle Grabowski
  2. 2. What’s Different and Why?• High tunnels provide a unique environment• Excess heat and humidity• Plants are handled more• Tight spacing of plants• Insects pest like thrips and white flies more likely than in field conditions© 2011 Regents of the University of Minnesota. All rights reserved.
  3. 3. Viruses
  4. 4. Tobacco Mosaic Virus (TMV) UFL S.M. Douglas, CTAg.Exp.station• Dark & light green mottle• Small, curled or distorted• Plants may be stunted S.M. Douglas, CTAg.Exp.station© 2011 Regents of the University of Minnesota. All rights reserved.
  5. 5. Tobacco Mosaic Virus(TMV)• Fruit Symptoms S.M. Douglas, CTAg.Exp.station• Poor yield• Distorted fruit• Uneven color S.M. Douglas, CTAg.Exp.station• Delayed ripening• Brown discoloration of inner walls© 2011 Regents of the University of Minnesota. All rights reserved. JP Jones, UFL
  6. 6. Tobacco Mosaic Virus• Infects over 150 genera – petunia, pepper, weeds• Can come in on seed coat• Very durable MSU Extension – Transmitted on tools, hands, clothing, leaf debris – Survives in plant debris in soil, on strings, poles, cross bars in tunnel, in cigarettes• Symptoms develop rapidly in heat© 2011 Regents of the University of Minnesota. All rights reserved.
  7. 7. Tomato Spotted Wilt Virus(TSWV)• Bronzing of leaves• Small darks spots on leaves, streaks on petioles & stems© 2011 Regents of the University of Minnesota. All rights reserved.
  8. 8. Tomato Spotted Wilt Virus(TSWV)© 2011 Regents of the University of Minnesota. All rights reserved.
  9. 9. Tomato Spotted WiltVirus (TSWV)• Early infection results in no fruit• Later infection – Ring spots on green fruit – Yellow to white rings on mature fruit© 2011 Regents of the University of Minnesota. All rights reserved. W.M. Brown, Bugwood.org
  10. 10. TSWV• Infects 300 species in 34 families P.M.J. Ramakers, APS Bugwood.org• Can spread in seed• Not as durable as TMV• Not easily transmitted on tools, hands, and from rubbing C.Hesselein, Bugwood.org• Thrip larvae pick up TSWV• Adult thrips transmit TSWV© 2011 Regents of the University of Minnesota. All rights reserved.
  11. 11. Identifying Virus Diseases withImmuno Strips• Agdia.com• 5 for $32-37• 25 for $105-120• Strips for many viruses• Most specific to 1 pathogen• A few combo strips© 2011 Regents of the University of Minnesota. All rights reserved.
  12. 12. UMN Plant Disease Diagnostic Clinic• Will identify the problem regardless what it is• Lab techniques – Electron Microscopy – ELISA – RT-PCR• http://pdc.umn.edu© 2011 Regents of the University of Minnesota. All rights reserved.
  13. 13. Managing Virus Diseases in Tunnels• Purchase seed from a reputable supplier that uses and acid treatment of seed• Purchase only transplants that have been tested and found to be virus free© 2011 Regents of the University of Minnesota. All rights reserved.
  14. 14. Managing Virus Diseases in Tunnels• Do not grow ornamentals with tomatoes and other crops• Control weeds in tunnels• Maintain a weed free buffer outside of tunnel• Do not allow use of tobacco products in the tunnel© 2011 Regents of the University of Minnesota. All rights reserved.
  15. 15. Managing Virus Diseases in Tunnels• Workers must have clean clothing and wash hands before entering the house• Wash hands and tools regularly while working• Immediately bag and remove infected plants• Manage thrips and other insect pests – TSWV, CMV• Sanitize strings, poles, boards and all surfaces in the tunnel after TMV infection© 2011 Regents of the University of Minnesota. All rights reserved.
  16. 16. Sterilizing Equipment & Hands• Soap and water• Carnation instant nonfat dry milk (20% wt/vol)• 1:10 bleach water solution (0.6% bleach)• Virkon (1% wt/vol) Lewandowski, D. J. Hayes, A.J. and Adkins, S. 2010. Surprising results from a search for effective disinfectants for Tobacco Mosaic virus – contaminated tools. Plant Disease 94:542-550© 2011 Regents of the University of Minnesota. All rights reserved.
  17. 17. Bacteria
  18. 18. Tomato Pith NecrosisPseudomonas corrugata Photos from M. McGrath, Long Island Hort. Research & Extension Center© 2011 Regents of the University of Minnesota. All rights reserved.
  19. 19. Pith Necrosis P. corrugata M. McGrath, Long Island Hort. Research & Extension CenterM. McGrath, Long Island Hort. Research & Extension Center © 2011 Regents of the University of Minnesota. All rights reserved.
  20. 20. Tomato Pith NecrosisPseudomonas corrugata• Favored by high humidity, cloudy weather, high N, rapid growth• Soil borne, possibly seed borne UFL• Does not appear to spread between plants on tools, hands etc© 2011 Regents of the University of Minnesota. All rights reserved.
  21. 21. Managing Pit Necrosis• Reduce humidity through ventilation• Provide adequate but not excessive fertilizer• Remove entire plant as soon as symptoms develop, bag the plant and bury and remaining debris• Copper fungicides are ineffective© 2011 Regents of the University of Minnesota. All rights reserved.
  22. 22. Bacterial CankerClavibacter michiganensis subsp. michiganensis• In field conditions or with overhead irrigation see• Birds eye fruit spots• Classic cankers at leaf axil D.Cuples Agri-Food Canada© 2011 Regents of the University of Minnesota. All rights reserved. D.Cuples Agri-Food Canada
  23. 23. Bacterial CankerC. michiganensis ssp. michiganensis MSU© 2011 Regents of the University of Minnesota. All rights reserved. ASTA MSU P.Bachi, UKY Bugwood.org
  24. 24. Bacterial CankerC. michiganensis ssp. michiganensis• Lives on surface of the seed & inside seed coat• Survives 5 yrs on seed – 2-3 yrs in plant debris – 1 month in soil or on plastic or cement – 1 year on plant material (wood stakes etc) or rock wool• Survives better in cool dry conditions than warm wet conditions© 2011 Regents of the University of Minnesota. All rights reserved.
  25. 25. Bacterial CankerC. michiganensis ssp. michiganensis• Enter through wounds or stomata• Spread on workers hands, clothing, tools, splashing water, forceful pesticide application• Favored by high temps (75-90F) wet conditions, low light and nutrient imbalance• May not see symptoms for 2-7 weeks© 2011 Regents of the University of Minnesota. All rights reserved.
  26. 26. Managing Bacterial Canker• Use certified disease free seed or treat seed in hot water for 25 min. at 125F• Reduce overhead watering of seedlings• Start with clean potting mix, pots & trays• Regularly disinfect cutting tools & worker hands• Copper fungicides are ineffective© 2011 Regents of the University of Minnesota. All rights reserved.
  27. 27. Managing Bacterial Canker• Immediately bag and remove infected plants• Remove several neighboring plants as well• Do not leave cull piles or plant debris near the tunnel• Control solanaceous weeds in & around the tunnel• Disinfect tunnel, crates, tools between crops• Rotate away from tomato & pepper 2-3 years© 2011 Regents of the University of Minnesota. All rights reserved.
  28. 28. ThanksQuestions?

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