Research Summary Abstract
Fortress (isoxaben + dithiopyr) was registered in 2018 for environmental horticulture crop uses. Between 2018 and 2020, IR-4 examined 17 crop species / genera to expand this label to other crops. Of these, 7 crop species exhibited no or transient injury. One species exhibited significant injury from isoxaben + dithiopyr at the 1X rate (Digitalis grandiflora).