The most destructive viral disease of stone fruit was detected in southwestern Michigan during routine testing by the Michigan Department of Agriculture and Rural Development (MDARD) in the summer of 2006. Thankfully, this was the state’s only encounter with Plum Pox Virus, but the scare quickly affected commerce and halted trade.
“We did a massive amount of surveying to ensure that we eradicated the virus. We still continue to monitor for this,” says Elizabeth Dorman, laboratory scientist for MDARD’s Pesticide and Plant Pest Management (PPPM) Division, which is responsible for responding to the detection of harmful insects and diseases, as well as certifying plants, fruits and vegetables.
Through the plant pathology lab at the MDARD Geagley Laboratory, scientists like Dorman are continuously conducting surveys to ensure early detection of plant health problems. They are especially cognizant of viruses, since no treatment is possible once found. Unlike the hosts of many plant diseases, plants infected with viruses must be destroyed, which is a significant investment loss for growers and dealers.
“We have inspectors who go out to growers, collect tissue and bring it back to the lab, where we screen for a panel of viruses that are specific to the host,” explains Dorman. Because viruses are tricky to detect early on, the PPPM heavily screens stock plants to prevent a pathogen from being passed on to cuttings. Both Michigan-grown and imported plant materials are subject to inspection.
Maintaining and Advocating Plant Health
More than 2,000 growers and 5,200 dealers are licensed by MDARD, the benefits of which are numerous, including higher market value, greater market access and pest-free stock for consumers. As part of this program, growers and dealers are inspected on an annual and biennial basis, respectively.
“Growers are trying to make sure they have the best product possible, and they can say that because they’re routinely inspected,” says Dorman. Plus, “you never know about that new virus coming.”
Along with regular testing, advanced technologies are crucial in MDARD’s fight for plant health. Smartphones are improving disease identification in the field and “quick strips” are used outside the lab to test for viruses before symptoms are present. In spring 2014, quick strips proved essential in monitoring for the highly contagious Tobacco Mosaic Virus, a big concern for the greenhouse industry.
Furthermore, the Michigan Floriculture Growers Council, which works closely with MDARD, has been vital in spearheading research and education on hot-button issues, such as emerging diseases, so growers are ready to implement best practices and eliminate development in their greenhouses.
“This year, we’ve talked about where some of those diseases are and how close they might be to Michigan,” says Val Vail-Shirey, executive director of the Michigan Floriculture Growers Council.
With these resources at hand, maintaining plant health in Michigan is not a hope, but a reality.