Azoxystrobin Crop Safety Summary – 2009

Frasier fir trees at Clawson’s Choose and Cut outside Boone.

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 ornamental crops. The label contains an extensive list of ornamental horticulture plants where Heritage can be used without causing phytotoxicity. From 1999 to 2002, the IR-4 Project conducted 100 trials on 75 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 53 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.

Link to Summary: Azoxystrobin Crop Safety