Preventing Target Spot in Flue-Cured Tobacco

(Updated: May 22, 2024, 9:23 a.m.)

Target spot has become a recurring problem in our tobacco.  Research has shown that this disease can cost a grower 5% in yield when the growing conditions support the development of this disease.  Now is the time to prepare to reduce the effects of this foliar disease.

An effective program to control target spot should begin before the disease is actually seen in the field.  Target spot is expected to become visible about layby in a tobacco field and is caused by a fungus called Rhizoctonia.   This fungus is present in every Pitt County field.

There are two products which are labeled for use to guard against target spot and they are Quadris and Manzate Pro Stick.  Azoxystrobin (e.g. Quadris) is labeled for use in the field and greenhouse. Mancozeb (e.g. Manzate Pro Stik) has a 24c label for use in tobacco in North Carolina, and is moderately effective for reducing target spot.   Last year, 58% of Pitt County tobacco farmers used Quadris to protect against target spot and 78% of growers used this product spraying only once.

Dr. Daisy Ahumada, NC State Tobacco Extension Plant Pathology Specialist, has outlined a "three-pronged, preventative approach to reducing target spot in your tobacco field.  These steps are as follows:
  • Use a post application of Quadris over-the-top 4-5 weeks after transplanting but before layby. Apply 8 fluid ounces in a volume of 25 gallons of water.  Apply using one nozzle directly over the row.
  • Use Manzate Pro Stik as a post application at the rate of 1.5 pounds per acre 2 weeks later. At this stage of growth, it is recommended to use a 3-nozzle arrangement for good coverage in a volume of 25 gallons per acre.
  • Use a second application of Quadris at a rate of 9 ounces per acre if there are signs of target spot development or if this disease is an annual problem. Use drop nozzles with a volume of 40-50 gallons per acre to provide good coverage.  Note:  There is a 21-day pre-harvest interval with Quadris.
Contact your local Cooperative Extension for more information.