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POSTERS: Chemical control

Evaluation of host plant defense inducers for the management of boxwood blight in North Carolina
Alejandro Llanos Melo - North Carolina State University. Sara Villani- North Carolina State University, Rachel Kreis- North Carolina State University

Boxwood blight, a devastating disease caused by Calonectria pseudonaviculata (Cps) has rapidly emerged as one of the most serious problems for the boxwood industry since it was reported in the United States in 2011. Concerns of frequent fungicide applications in landscapes for disease management have led us to find other management tools. The aim of this research was to evaluate the effectiveness of host plant defense inducers; Actigard® (acibenzolar-S-methyl), Lifegard® (Bacillus mycoides isolate J), and ProPhyt® (Potassium phosphite) under different application frequencies and methods. Trials were conducted at two locations: A container pad under artificial inoculum conditions and an established landscape planting with a history of boxwood blight. At each location, two cultivars that vary in their susceptibility to boxwood blight; Buxus sinica ‘Justin Brouwer’ (JB) and B. sempervirens x B. microphylla ‘Green Velvet’(GV) were evaluated. At both locations and for both cultivars, drench applications of Actigard® provided significantly greater control against boxwood blight, compared to the untreated program (p < 0.05). Current and future research is focusing on the expression of genes that encode pathogenesis-related (PR) proteins following applications of host plant defense inducers and integration of these tools into conventional fungicide programs for the management of boxwood blight.