Research Summary Abstract
Metconazole was registered as Tourney 50WDG in the United States in 2007 as a turf fungicide. In 2010, uses for ornamental horticulture plants in greenhouse, nurseries, and landscapes were added. The commercial label contains a list of 49 woody ornamental plants exhibiting no or minimal injury. However, because metconazole is in the triazole class it could cause symptoms similar to plant growth regulators and additional testing is warranted on additional herbaceous and woody ornamental species. Between 2010 and 2016, the IR-4 Project completed 166 trials on 41 ornamental plant species examining phytotoxicity related to foliar applications of Tourney. In these trials, 22 species or genera exhibited minimal or no injury after foliar applications. Of these, 14 are already on the Tourney label; Buxus sp., Calibrachoa sp., Chamaerops humilis, Hemerocallis sp., Hydrangea sp., Lantana sp., Liriope sp. and Verbena sp. are the eight crops not yet listed. Based on this information, it is recommended that these be added to the list of tolerant plants on the Tourney 50WDG label. Four crops exhibited stunting: begonia, impatiens, pansy and zinnia.