Location: Mycology and Nematology Genetic Diversity and Biology LaboratoryTitle: Evaluation of boxwood cultivars for resistance to boxwood blight, 2020
|BECKER, LINDSEY - North Carolina State University|
|ADHIKARI, URMILA - North Carolina State University|
|MAY, TED - Ag Biotech, Llc|
|Crouch, Jo Anne|
|CUBETA, MARC - North Carolina State University|
Submitted to: Plant Disease Management Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/4/2021
Publication Date: 3/4/2021
Citation: Becker, L.E., Adhikari, U., May, T., Shishkoff, N., Crouch, J., Cubeta, M.A. 2021. Evaluation of boxwood cultivars for resistance to boxwood blight, 2020. Plant Disease Management Reports. 15:OT008. Available: https://www.plantmanagementnetwork.org/pub/trial/pdmr/volume15/abstracts/ot008.asp
Interpretive Summary: Boxwood plants worldwide are threatened by a deadly fungal disease known as boxwood blight. Twenty cultivars of boxwood were evaluated for susceptibility to boxwood blight to determine if differences in susceptibility existed. Cultivars of the most commonly used boxwood species (Buxus sempervirens) showed high levels of damage due to blight, and cultivars of species such as B. microphylla, B. harlandii and B. riparia were much less susceptible. In particular, the Japanese boxwood cultivar ‘Golden Dream’ showed no blight symptoms. This information will be used by nursery and landscape industry professionals, gardeners, and extension personnel to make informed recommendations and decisions about which boxwood cultivars to grow and use in the landscape to minimize the risk of boxwood blight.
Technical Abstract: This field experiment evaluated the relative level of resistance in 21 boxwood cultivars to the fungus Calonectria pseudonaviculata, causal agent of boxwood blight disease affecting Buxus sp. (boxwood). Buxus sempervirens English/Suffruticosa plants had the highest level of leaf blight, stem canker and defoliation per plant area and did not differ from B. sempervirens cultivars Vardar Valley and Justin Brouwers. The B. microphylla var. japonica cultivar Golden Dream had the lowest leaf blight and stem canker disease ratings and disease levels differed significantly from those of English/Suffruticosa, Vardar Valley, Justin Brouwers, and Dee Runk. Fourteen of the 21 boxwood cultivars (John Baldwin, Green Mound, Green Mountain, Sprinter, Little Missy, Calgary, TM110, Cranberry Creek, NewGen Freedom, Jim Stauffer, NewGen Independence, Winter Gem, Franklin’s Gem, and Richard) significantly differed from the most susceptible cultivars (English/Suffruticosa, Vardar Valley, Justin Brouwers), but did not differ significantly from the least susceptible cultivar, Golden Dream, for leaf blight and stem canker disease ratings.