Sanitation Protocol for Valdensinia Leaf-drop Disease

Prepared by Dr. Seanna Annis, Blueberry Pathologist, School of Biology and Ecology, University of Maine, Orono, ME, 04469.

There is NO tested fungicide that will eradicate this disease from a field. Fungicides will only suppress the disease by protecting the plants.  Once in a field, the fungus will produce new spores and infect plants after any three-day wet period throughout the season.  Many fungicide applications will be necessary throughout the prune and crop years to protect plants if this disease is in your field.  We want to avoid the trouble (hopefully it is not a disaster) that is hitting growers in Nova Scotia this year from Valdensinia leaf drop disease.

THE KEY IS: DO NOT MOVE ANY DISEASED LEAVES AROUND.

  • Do NOT walk or drive through any areas of leaf drop or brown leaf spots in a field. Do NOT harvest any area with suspected (or confirmed) Valdensinia leaf drop.  Once, confirmed to have the disease, BURN any plants with Valdensinia leaf spot to the ground including burning all leaf litter, as soon as possible.

General Precautions

  • At the edge of ANY field, you visit,  brush leaf litter off of your footwear and vehicle before going to another field. Brush off your footwear and vehicle tires with your hand or something that will NOT collect leaf litter.  (If you use a brush, clean it off regularly).
  • ALL equipment, vehicles, ATVs, harvesters, blueberry boxes, etc. need to be cleaned off of leaf litter BEFORE they are moved out of a field.  All equipment should have no leaf litter on it before you let it into your field. Spraying with a 5% bleach solution (one part bleach to 19 parts water),  other disinfectant or a weak soap solution may help to remove the leaf litter, but may NOT kill the fungus (see below).
  • What will NOT WORK: Soaking infected leaves in 10% bleach solution for 1½ minutes did NOT kill the fungus!  Just dipping footwear or spraying equipment with disinfectant or bleach solution will NOT work, UNLESS the leaf litter is removed.

Please contact Seanna Annis at the Blueberry Hotline (1.800.897.0757) if you have any questions.

Information in this publication is provided purely for educational purposes. No responsibility is assumed for any problems associated with the use of products or services mentioned. No endorsement of products or companies is intended, nor is criticism of unnamed products or companies implied.

© 2009

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