American-Hort and the Horticulture Research Fund in conjunction with the NPB, announced a revised, updated Boxwood Blight Best Management Practices refrence, version 2.0, now available online.
Two closely related fungi, Calonectria pseudonaviculata and C. henricotiae, can cause boxwood blight. Currently only one, C. pseudonaviculata, has a known presence in the US. Both, however, are present in the EU; so, the threat remains for C. henricotiae to come to the US. Despite being the same genus (Calonectria), these two species have some key differences, such as different responses to temperatures and fungicides.
While researchers know of only three host plants for boxwood blight, boxwood (Buxus), Pachysandra, and sweet box (Sarcococca), the economic impact is potentially quite large. Boxwood blight has been confirmed in 24 states, with Illinois and Missouri being among the latest detections. There are a few states with significant boxwood production where the disease hasn’t been confirmed, such as Texas and Louisiana.
Dr. Chuan Hong, plant pathologist at Virginia Tech and the lead researcher of key boxwood blight projects said: “Boxwood blight risk is mounting for horti-cultural production facilities, especially those near an infested landscape site, now in 24 states. This BMP update with the latest research from the Farm Bill projects was well timed and will serve individual growers and the horticulture industry as a whole very well.”
To access the latest version of the Boxwood BMPs, visit the AmericanHort Knowledge Center.