Research Summary Abstract
Azoxystrobin was registered as Heritage in the United States in 1997 as a turf fungicide. In April 2003, this label was updated to include applications for certain diseases on environmental horticulture crops.The label contains an extensive list of environmental horticulture plants where Heritage can be used without causing phytotoxicity. From 1999 to 2014, the IR-4 Project conducted 107 trials on 77 ornamental plant species examining phytotoxicity related to Heritage applications. In these trials, only 2 crops (Pseudotsuga menziesii and Tsuga heterophylla) exhibited noticeable, significant injury and that was a slight height reduction and stem swelling at the 2X and 4X rates applied as drench to emerged seedlings. Based on this information, it is recommended that 54 plants in the IR-4 trials be added to the list of tolerant plants with the precautionary statements in the Plant Safety and Tolerant Ornamentals Plant sections of the current Heritage 50WG label.