Heterobasidion Root Disease Interactive Guide
Result
HRD is present in the stand.
Learn more in Chapter 4 of the HRD guidelines.
Recommendation
No treatment is required December 1 through March 31. Treatment of pine and spruce stumps is considered unnecessary from 12/1 to 3/31 because of the following biological and operational reasons.
- The risk of spore dispersal is low when the temperature is low.
- Pesticides that are currently available in Wisconsin need to be applied as an aqueous mixture. Therefore, treatment is not feasible during periods of cold temperatures.
Things to consider
If harvesting occurs from April 1–November 30, preventive stump treatment on pine and spruce is recommended if more than 50% of the stand is pine and/or spruce. The minimum tree size for treatment is merchantable size. No treatment is required from December 1–March 31. Harvesting without preventive stump treatment can be considered April 1–November 30 under certain conditions listed as Exceptions or Modifications in this chapter.
Background information
HRD spore production (Chapter 5.3)
Types and efficacy of pesticides for prevention of HRD (Chapter 5.8)