New technology is coming to the apple and pear industry to help control fireblight. Actigard is a systemic compound with a unique mode of action that mimics the natural systemic-activated resistance response found in many plants. When applied preventatively, much like vaccinations are given to humans to ward off certain diseases, Actigard stimulates or induces the plant’s natural defenses, turning on the genes that are involved in fighting off infection from various diseases. Actigard (acibenzolar-S-methyl), a product of Syngenta, is registered for other crops, including tomatoes, tobacco, and berry fruits. Registration is pending for apples and pears.
In pome fruit, Actigard is applied late bloom or as a rescue treatment to help manage fireblight, said Dr. Ken Johnson, plant pathologist at Oregon State University. Research has shown improved fireblight protection when Actigard is used in combination with antibiotics, reducing strikes per tree by nearly half.
“That’s why we like Actigard—we’re cutting down blight incidence by 50 percent or so by going with a late application,” Johnson said. “In the blight business, that’s a meaningful response.”
One of the primary benefits to Actigard is its long residual life of seven to ten days during late petal fall, a time when antibiotics are ineffective, he said. “You can use Actigard late for petal fall, rat-tail, and shoot blight in susceptible cultivars—it’s like using Apogee