Grower News

University of Michigan researcher Mary Hausbeck shares her insights on the prevalent fungus after decades of experience. Subscribe Hausbeck working in the greenhouse Mary Hausbeck As part of her research for a graduate degree in horticulture, Mary Hausbeck was conducting a geranium cultivar evaluation when Pythium became a problem in the greenhouse. Spraying silver ethyl sulfate on the foliage to prevent petal shatter in the seeded geraniums appeared to make the problem worse: within days after the foliar application, plants infected with Pythium died. Other plant pathologists at Michigan State University were being contacted about similar issues in local greenhouses. Hausbeck started researching whether the application of silver ethyl sulfate did prompt an enhanced Pythium infection and her interest in the disease has continued across the decades. Now, as a distinguished professor and extension specialist at Michigan State University, Hausbeck continues researching the damaging fungus. Greenhouse Management : What new discoveries have been made since you started studying Pythium in the 1980s? Mary Hausbeck: Each year, my lab runs new trials to determine if there are new fungicides or biocontrol products that can be helpful. There have been a lot of new fungicide products released to address the group of water molds, including Pythium. We’ve made big advances with products to control Phytophthora and downy mildew, but they are “B-team” players that are not as good as older products like Subdue and Truban. So, there is still work to do. Recently, we sampled and tracked Pythium problems across some of the major floriculture crops and were able to determine which Pythium types were affecting these crops and which of the Pythium types tend to become resistant to fungicides. GM: What are some of the challenges to treating Pythium? MH: The first challenge is to make sure the problem is accurately diagnosed. We also don’t have as many “new” products that are highly effective against Pythium root rot, which can lead to overuse of the products that have been available for many years, which leads to another challenge of Pythium developing resistance if fungicides are overused. Timing treatments is an […]

Source: www.greenhousemag.com