APS Homepage

Poster: Biology & Disease Mgmt: Cultural Control


Eradication of the boxwood blight pathogen, Calonectrua pseudonaviculata, in compost
R. HARVEY (1), D. Davis (1), J. Pecchia (1) (1) Penn State University, U.S.A.

Calonectria pseudonaviculata, the causal agent of boxwood blight, is a serious threat to boxwood growers across the country. Boxwood blight is currently present in at least 15 US states, however this number is likely to increase as more infections are found. Due to the production of microsclerotia by the pathogen, there is concern that if infected plants are composted, the pathogen could survive the composting process and possibly cause further infections if the compost is used around healthy boxwoods, or other susceptible plants. To determine survivability during the composting process, discreet microsclerotia were inoculated into compost within a bioreactor system and subsequently sampled at set time/temperature intervals. Survival was rated as a plus/minus system based on the presence of microsclerotia germination. The data presented here are a refinement of data previously presented previously, and suggest that C. pseudonaviculata microsclerotia will not survive composting at greater than 50 °C for over 24 hours. Further work needs to be done to define the minimum time/temperature that is sufficient to ensure complete eradication. In addition, similar research is needed to assess pathogen survival within infected plant material and to confirm the time/temperature combinations in vivo.