Lontrel (clopyralid) was initially registered in 1998 for ornamental horticulture uses. This initial label contained an extensive list of ornamental horticulture plants where Lontrel could be used without causing phytotoxicity. From 1985 to 2002, IR-4 examined 66 ornamental plant species for phytotoxicity related to Lontrel applications. Of the researched crops, only two crops (Hemerocallis sp. and Ilex cornuta) can be added to the label at this time based on the data provided here.
Research Summary Abstract