Boxwood blight, caused by the fungus Calonectria pseudonaviculata, is a serious fungal disease of boxwood that results in defoliation and decline of susceptible boxwood.
In Florida, Boxwood blight was discovered in April 2015 in a commercial nursery in North Florida by the University of Florida, NFREC Plant Diagnostic Clinic and the Division of Plant Industry, FDACS. The disease was on liners of Common boxwood (B. sempervirens) and ‘Green Velvet ‘ (B. sinica var. insularis x B. sempervirens ‘Suffruticosa’) cultivars shipped from Oregon.
The most characteristic symptoms of boxwood blight on susceptible boxwood cultivars are brown leaf spots (Fig. 1) that lead to defoliation.
The National Plant Diagnostic Network (NPDN) First Detector program, which promotes the early detection of invasive, exotic plant pathogens, arthropods, nematodes, and weeds, offers an E-learning module on boxwood blight.
Bush et al. 2014. Virginia Cooperative Extension. Accessed 9/8/2015 – http://pubs.ext.vt.edu/PPWS/PPWS-29/PPWS-29-pdf.pdf
Paret, Matthews, 2015.University of Florida, North Florida Research and Education Center, Quincy. Accessed: 9/8/2015 – http://nwdistrict.ifas.ufl.edu/phag/2015/06/02/pest-alert-boxwood-blight/