Impatiens Downy Mildew NJNLA 2/19/2013 Cristi Palmer, IR-4 Photos by M. Daughtrey Before: Sept 15, 2011 After: Oct 11, 2011
The following slides were compiled from presentations provided by Ms. Margery Daughtrey, Dr. Mary Hausbeck, and Dr. Aaron Palmateer. Cristi Palmer greatly appreciates their generosity.
Recent IDM History IDM first seen in Busy Lizzies in 2003 in UK 2004 first seen on greenhouse crops in US, only one reported case in UK 2005 2007 - sporadic observations 2008 wide spread observations and oospores observed in UK 2009 2010 major declines in impatiens in Saratoga Springs, NY 2011 2012 widespread reports throughout US
2011 (Mostly Landscape) Reports of Impatiens Downy Mildew 5 * States with reported IDM 2012 Syngenta. Document Classification: Public
2012 Landscape & Greenhouse Reports of Impatiens Downy Mildew 5 * States with reported IDM
Symptoms Stippling Downcurling Leaves Defoliation Flower loss Collapse of Plants Photos by M. Daughtrey Photo by M. Hausbeck Photo by M. Daughtrey
2004 NY M. Daughtrey
Photo by A. Windham
Sporangia on stalk growing from infected impatiens. Photo by M. Hausbeck
Photo by M. Daughtrey
Photo by M. Daughtrey
Impatiens Downy Mildew is a Challenge! Effective management requires: Coordination Suppliers / plug producers Wholesalers Finishers Retailers Knowledge Disease biology Optimal management program(s)
IDM Management: Plants from Suppliers Inspect incoming materials Find out fungicide pedigree Try to separate impatiens from different sources Separate seed-raised and vegetative propagated impatiens IDM is not known to be seed transmitted Separate blocks by 40 inches to minimize cross contamination by splash dispersal Dispersal by air movement is still possible.
IDM Management: Cultural Practices Minimize greenhouse humidity and leaf wetness, especially at night Adequate drainage Good air movement Irrigate in the morning or when plants can dry quickly Scout routinely looking for early leaf symptoms Remove symptomatic plants and any fallen leaves Do not compost If sporulation is present Remove adjacent plants within 3 feet Disinfest greenhouse surfaces
IDM Management: Chemical Control Apply preventive treatments Most foliar fungicides have < 7 days residual Drench applications of Adorn and Subdue MAXX have 4 6 week residual Rotate among fungicides with different modes of action (refer to FRAC code) Many choices among 10+ classes
Preventative Control Options Fungicide FRAC # Re-entry Interval Use Site (example) Adorn (fluopicolide) 43 12 h G, N, L Disarm O (fluoxastrobin) 11 12 h G, N FenStop (fenamidone) 11 12 h G Heritage (azoxystrobin) 11 4 h G, N, L Micora (mandipropamid) 40 4 h G, N Orvego (ametoctradin + dimethomorph) 45 + 40 12 h G, N Pageant (pyraclostrobin + boscalid) 11 + 7 12 h G, N, L Protect DF (mancozeb) M 24 h G, N, L Segway (cyazofamid) 21 12 h G, N, L Stature (dimethomorph) 40 12 h G, N Subdue MAXX 4 Drench 0 h Foliar 48 h G, N, L Vital (potassium phosphate) 33 4 h G, N, L *** This list is not exhaustive. Other products may provide similar levels of efficacy but have not been tested and/or results published as of 2/15/2013.
Preventative Control Options Caveats: Curative applications are not effective. Must apply preventatively!!! Residual efficacy is 7 days or less for foliar applications Adorn & Subdue can be applied preventatively 6-7 days prior to inoculation and still be effective; others are not quite as good under heavy inoculations. Must rotate among different classes to reduce potential for resistance Must get excellent coverage for best efficacy including bottom of leaves, even for systemic products
1. Non-inoculated Control 2. Inoculated Control 3. Orvego 11 oz sprench 4. Orvego 14 oz sprench 5. Orvego 11 oz airblast 6. Orvego 14 oz airblast 7. Pageant 12 oz sprench 8. Pageant 12 oz airblast 9. Stature SC 6.12 oz sprench 10. Stature SC 12.25 oz sprench 11. Stature SC 6.12 oz airblast 12. Stature SC 12.25 oz airblast 13. Heritage 4 oz sprench 14. Heritage 4 oz airblast A. Palmateer, UF TREC, 2012
7 days Untreated 1. Non-inoculated Control 2. Inoculated Control 3. Orvego 11 oz sprench 4. Orvego 14 oz sprench 5. Orvego 11 oz airblast 6. Orvego 14 oz airblast 7. Pageant 12 oz sprench 8. Pageant 12 oz airblast 9. Stature SC 6.12 oz sprench 10. Stature SC 12.25 oz sprench 11. Stature SC 6.12 oz airblast 12. Stature SC 12.25 oz airblast 13. Heritage 4 oz sprench 14. Heritage 4 oz airblast
24 days Untreated bed 13 10 7 4 1 14 11 8 5 2 12 9 6 3 1. Non-inoculated Control 2. Inoculated Control 3. Orvego 11 oz sprench 4. Orvego 14 oz sprench 5. Orvego 11 oz airblast 6. Orvego 14 oz airblast 7. Pageant 12 oz sprench 8. Pageant 12 oz airblast 9. Stature SC 6.12 oz sprench 10. Stature SC 12.25 oz sprench 11. Stature SC 6.12 oz airblast 12. Stature SC 12.25 oz airblast 13. Heritage 4 oz sprench 14. Heritage 4 oz airblast
32 days Untreated bed 13 10 7 4 1 14 11 8 5 2 12 9 6 3 1. Non-inoculated Control 2. Inoculated Control 3. Orvego 11 oz sprench 4. Orvego 14 oz sprench 5. Orvego 11 oz airblast 6. Orvego 14 oz airblast 7. Pageant 12 oz sprench 8. Pageant 12 oz airblast 9. Stature SC 6.12 oz sprench 10. Stature SC 12.25 oz sprench 11. Stature SC 6.12 oz airblast 12. Stature SC 12.25 oz airblast 13. Heritage 4 oz sprench 14. Heritage 4 oz airblast
38 days Untreated bed 13 10 7 4 1 14 11 8 5 2 12 9 6 3 1. Non-inoculated Control 2. Inoculated Control 3. Orvego 11 oz sprench 4. Orvego 14 oz sprench 5. Orvego 11 oz airblast 6. Orvego 14 oz airblast 7. Pageant 12 oz sprench 8. Pageant 12 oz airblast 9. Stature SC 6.12 oz sprench 10. Stature SC 12.25 oz sprench 11. Stature SC 6.12 oz airblast 12. Stature SC 12.25 oz airblast 13. Heritage 4 oz sprench 14. Heritage 4 oz airblast
46 days Untreated bed 13 10 7 4 1 14 11 8 5 2 12 9 6 3 1. Non-inoculated Control 2. Inoculated Control 3. Orvego 11 oz sprench 4. Orvego 14 oz sprench 5. Orvego 11 oz airblast 6. Orvego 14 oz airblast 7. Pageant 12 oz sprench 8. Pageant 12 oz airblast 9. Stature SC 6.12 oz sprench 10. Stature SC 12.25 oz sprench 11. Stature SC 6.12 oz airblast 12. Stature SC 12.25 oz airblast 13. Heritage 4 oz sprench 14. Heritage 4 oz airblast
7 days Subdue GR 30 oz/1000 sq ft 1. Non-inoculated Control 2. Inoculated Control 3. Orvego 11 oz sprench 4. Orvego 14 oz sprench 5. Orvego 11 oz airblast 6. Orvego 14 oz airblast 7. Pageant 12 oz sprench 8. Pageant 12 oz airblast 9. Stature SC 6.12 oz sprench 10. Stature SC 12.25 oz sprench 11. Stature SC 6.12 oz airblast 12. Stature SC 12.25 oz airblast 13. Heritage 4 oz sprench 14. Heritage 4 oz airblast
46 days Subdue GR 30 oz/ 1000 sqft 1 4 7 10 13 2 5 8 11 14 3 6 9 12 1. Non-inoculated Control 2. Inoculated Control 3. Orvego 11 oz sprench 4. Orvego 14 oz sprench 5. Orvego 11 oz airblast 6. Orvego 14 oz airblast 7. Pageant 12 oz sprench 8. Pageant 12 oz airblast 9. Stature SC 6.12 oz sprench 10. Stature SC 12.25 oz sprench 11. Stature SC 6.12 oz airblast 12. Stature SC 12.25 oz airblast 13. Heritage 4 oz sprench 14. Heritage 4 oz airblast
54 days Subdue GR 30 oz/1000 sqft 1 4 7 10 13 2 5 8 11 14 3 6 9 12 1. Non-inoculated Control 2. Inoculated Control 3. Orvego 11 oz sprench 4. Orvego 14 oz sprench 5. Orvego 11 oz airblast 6. Orvego 14 oz airblast 7. Pageant 12 oz sprench 8. Pageant 12 oz airblast 9. Stature SC 6.12 oz sprench 10. Stature SC 12.25 oz sprench 11. Stature SC 6.12 oz airblast 12. Stature SC 12.25 oz airblast 13. Heritage 4 oz sprench 14. Heritage 4 oz airblast
60 days Subdue GR 30 oz/1000 sqft 1 4 7 10 13 2 5 8 11 14 3 6 9 12 1. Non-inoculated Control 2. Inoculated Control 3. Orvego 11 oz sprench 4. Orvego 14 oz sprench 5. Orvego 11 oz airblast 6. Orvego 14 oz airblast 7. Pageant 12 oz sprench 8. Pageant 12 oz airblast 9. Stature SC 6.12 oz sprench 10. Stature SC 12.25 oz sprench 11. Stature SC 6.12 oz airblast 12. Stature SC 12.25 oz airblast 13. Heritage 4 oz sprench 14. Heritage 4 oz airblast
Combo of Subdue + Phos acid Combo of Heritage + Phos acid Aliette Heritage These 2 were untreated Phos acid A14685C SubdueMAXX 5 Weeks After Drench in the Greenhouse, M. Daughtrey, 2012 (made just before bringing outdoors & exposing to DM)
Shade alternatives to Impatiens walleriana Alternanthera Begonia Browalia Caladium Coleus Fuschia Hypoestes (polka dot plant) NG Impatiens Oxalis Perilla Torenia Scutellaria American Farms C. Palmer G. Weigel Willoway Nursery
Partial Shade alternatives to Impatiens walleriana Cyclamen Diascia Dichondra Euphorbia hypericifolia Ivy Geranium Heliotrope Ipomoea Iresine Lobelia Lobularia Nemesia Nicotiana Plectranthus Salvia splendens Sanvitalia Denver Plants DavesGarden.com Missouri Botanical Garden CalysFlowers.com
Additional Resources American Floral Endowment http://www.endowment.org Cornell Cooperative Extension http://ccesuffolk.org/floriculture-program/
M. Daughtrey