Dithiopyr Crop Safety – 2018

Soft rush plant in pond

Research Summary Abstract

Dimension was initially registered in 1992 for ornamental horticulture uses. This initial label contained an extensive list of ornamental horticulture plants in 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 2017, IR-4 conducted 239 trials with Dimension 2EW formulation applied as over-the-top spray on 111 species / genera, including ornamental grasses to further expand the treatable plant list in the current label. Of the researched crops and Dimension formulations, 11 crops (Berberis thunbergii, Eragrostis curvula, Hemerocallis sp., Ilex crenata, Juncus effusus, Leymus arenarius, Muhlenbergia capillaris, Narcissus sp., Pennisetum alopecuroides, Pseudotsuga mensiezii, and Thuja occidentalis) can be added for over-the-top spray at this time based on the data provided here. It is recommended the trials conducted using emulsifiable concentrate formulations be repeated with Dimension 2EW.

Link to Summary: Dithiopyr Data Summary