Location: Foreign Disease-Weed Science ResearchTitle: Survival of lab grown Calonectria pseudonaviculata microsclerotia during small scale composting
|HARVEY, ROBERT - Pennsylvania State University|
|DAVIS, DONALD - Pennsylvania State University|
|PECCHIA, JOHN - Pennsylvania State University|
Submitted to: Bioresource Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/12/2018
Publication Date: 1/15/2019
Citation: Harvey, R.J., Davis, D.D., Shishkoff, N., Pecchia, J.A. 2019. Survival of lab grown Calonectria pseudonaviculata microsclerotia during small scale composting. Bioresource Technology. 27(1):24-34. https://doi.org/10.1080/1065657X.2018.1536865.
Interpretive Summary: Boxwood blight is a new and emerging disease affecting boxwood, an economically important plant that is also culturally significant, featured in many historical Early American gardens such as those found at Mount Vernon, Monticello, and Colonial Williamsburg. In 2011 the pathogenic fungus causing blight (Calonectria pseudonaviculata) was reported in North Carolina, Connecticut, Pennsylvania, Maryland, Oregon, and Virginia (2011), in New York, Ohio, Delaware, and New Jersey (2013), in Kansas, Kentucky, Tennessee, Georgia, and Massachusetts (2014), and subsequently in West Virginia, Alabama, Florida, South Carolina, Washington, Illinois, Maine, New Hampshire, and Rhode Island, and California. Most recently, in late 2017, Indiana reported that a shipment of wreaths with infected boxwood material was received and sold by a local Boy Scout troop. Research suggests that the pathogen survives for long periods in soil and litter, making it difficult to replant boxwood in areas where the pathogen is established. Composting of disease plant litter has been shown with other plant diseases to serve as an effective way to eradicate a pathogen. The objective of this study was to evaluate survival of the pathogen under various combinations of composting time and temperature. It was determined that no pathogen survival would be expected in compost that sustained temperatures greater than 122 °F for 24 hours, offering a way to dispose of diseased material from affected sites without spreading the pathogen.
Technical Abstract: Boxwood blight, caused by Calonectria pseudonaviculata in the United States, is a devastating fungal disease of Buxus spp. first observed in the United States in 2011. Subsequently, this pathogen has spread to 26 other states, both on the east and west coasts. Initial outbreaks led to large monetary losses, therefore making control and management imperative. Due to the resistant nature of the produced microsclerotia, concern arose over the potential for compost to serve as a disease vector. Plant pathogen dissemination in compost is a known phenomenon, and depends mainly on the attributes of the organism. Previous work demonstrated that Ca. pseudonaviculata is very stable in mesophilic temperatures, however no previous work evaluated compost survival. It was the goal of this paper to assess the survival of Ca. pseudonaviculata microsclerotia in a composting bioreactor system. It was determined that no pathogen survival would be expected in compost that sustained temperatures > 50 °C after 24 h.