Blue Mold Found on Tobacco Transplants in Bluegrass Greenhouse

Source from:  By CHRIS MILAM-Agriculture/Natural Resources Agent for Logan County 06/06/2007

Kenny Seebold and Gary Palmer report that blue mold was found today (June 1) on tobacco seedlings in a greenhouse in Fayette County. Active sporulation was observed in a small portion of the transplant facility, and was apparently in an early stage of development. At the moment, the source of the blue mold outbreak has not been determined. Measures were taken to contain the outbreak and limit spread of the pathogen, Peronospora tabacina. The entire greenhouse was sealed to avoid the further release of blue mold into the outside environment and to permit heat to destroy infected plants and those that were potentially infected. All plants with sporulating lesions were placed in clear plastic bags that were sealed and leftinside the greenhouse as an additional precaution. It is advisable at this point to make sure that any tobacco in float beds (outdoor and greenhouse) be treated with Dithane DF to protect against blue mold. This is especially important for tobacco being grown near Fayette County, but would also be a good measure of insurance for the rest of the region. The recommended rate of Dithane DF is 0.5 lb/100 gal of finished spray (or 1 teaspoon of product per gallon). Since Dithane is a protectant, it needs to be in place prior to the arrival of inoculum for best effect and this means preventive applications are the key for success. Apply as a fine spray to achieve thorough coverage. The risk at this time to plants in the field is low due to the prevailing hot and dry weather. However, if we enter a period of cool and rainy conditions, plants should be treated with Dithane DF (1.5-2 lb/A) + Acrobat 50 WP (2-8 oz/A), Quadris (6-12 fl oz/A), or Actigard (0.5 oz/A). Plants need to be at least 18-in tall before receiving an application of Actigard, and the material should be applied 3-5 days before infection for the product to work effectively ?lease let me know if you find blue mold or suspect it in your area. I will continue to send out e-mails to keep you posted on the situation, and you can visit the Kentucky Tobacco Disease Information page for regular updates on blue mold and other diseases (http://www.uky.edu/Ag/kpn/kyblue/kyblue.htm). Enditem