Dithiopyr Crop Safety – 2022

Research Summary Abstract

Dimension was initially registered in 1992 for environmental horticulture uses. This initial label contained an extensive list of plants for landscapes where Dimension could be used without causing phytotoxicity. From 1992 through 2004, IR-4 conducted 68 trials on 42 species / genera, including several different fern species grown in field containers, to contribute crop safety data for dithiopyr formulations. In 2006, the new Dimension 2EW label contained registered uses for field container and in ground nursery production, the first dithiopyr product to have these use sites. A revised label was published in 2015 adding more crop species to the label. This current label recommends directed spray as the application method for almost all crops. During 2014 to 2021, IR-4 conducted 252 trials with Dimension 2EW formulation applied as over-the-top spray on 101 species / genera, including ornamental grasses and sedums to further expand the treatable plant list in the current label. Of the researched crops and Dimension formulations, 16 crops (Aronia melanocarpa, Berberis thunbergii, Eragrostis curvula, Eucalyptus sp., Euonymus fortunei, Hemerocallis sp., Ilex crenata, Juncus effusus, Leymus arenarius, Muhlenbergia capillaris, Narcissus sp., Pennisetum alopecuroides, Pseudotsuga mensiezii, Rosa sp ‘Knockout’, Taxus cuspidata, Thuja occidentalis) can be added for over-the-top spray at this time based on the data provided here.

Link to Summary: Dithiopyr Crop Safety Summary