Who better to provide an update on the pests and diseases growers need to worry about this season than a panel of five plant experts?
That’s who spoke about the topic at this summer’s Cultivate’23, organized by AmericanHort. On the panel were Matthew Krause, technical lead at Lallemand Plant Care; J.C. Chong, Ph.D., technical development manager at SePRO and former professor and Extension specialist of turf and ornamental entomology at Clemson; Janna Beckerman, Ph.D., professor and Extension plant pathologist at Purdue; Michael Brownbridge, Ph.D., biological program manager at BioWorks Inc.; and Dr. Sarah Jandricic, greenhouse floriculture IPM specialist with the Ontario Ministry of Agriculture, Food & Rural Affairs.
Chong began with Thrips parvispinus (also known as Taiwanese thrips). “They are a big issue, especially in Florida,” he said. “There’s a lot of anxiety over them, but the research is really good.” He reported that there are some insecticides that help against this new pest – even though Chong believes they will flare up again in autumn.
“They’re dealing with the same issue in Canada with tropical cuttings,” Jandricic said of the new thrips. Up north, growers started combatting them with biocontrols and mechanical control (removal of flowers and sticky cards), then brought in insecticides (and saw 16 weeks of control).
“It’s definitely possible to control them with IPM for now,” she added.
And while Brownbridge noted T. parvispinus is “the new kid on the block,” western flower thrips are still an issue. He advised growers to stay proactive in their management plans. (This thrips is native to the Southwestern U.S. but has spread to other continents, including Europe, Australia and South America.)
Beckerman mentioned vascular streak disease as one to watch out for, as 22 different genera of plants are now being affected by it.
And while spotted lanternfly is still not a disease vector, it does makes plants it feeds on more susceptible to other diseases.
The panel agreed that weather is playing an increasingly prominent role in how pests and diseases affect plants. They can get stressed and more susceptible to problems, just like humans.
“We’re not dealing with just one thing at any one time. Focusing on one problem often leads to others,” Beckerman said. “We need to look at the big picture.”
That big picture also includes new “cures.” Brownridge noted that researchers need to make sure new biocontrol solutions are fully approved by USDA-APHIS so they don’t create new problems of their own. Approval can be a process that takes several years.
Proper identification of pests and diseases is also part of the big picture. Beckerman cautioned growers to correctly identify any issue before they go to their “nuclear option.”
Jandricic suggested using the blog at onfloriculture.com to help identify issues. “And don’t count out mechanical control,” she said. “I know a grower who used a Shop-Vac to suck up a bunch of bugs. And Alyssum works great as a trap plant.”
Beckerman wrapped up the panel by stating that growers often overlook sanitation to their own peril. “There’s no glory and no fun in cleaning, but cleanliness is next to godliness,” she said. “You need to control your environment as best you can. And if something doesn’t look good, throw it out.”
by Courtney Llewellyn