Hemp producers struggle to manage weeds and have very few herbicide options available, with no conventional herbicides registered for use prior to April 2023. The Environmental Protection Agency (EPA) has established the first pesticide tolerance in hemp and it is for the herbicide ethalfluralin (Final Rule).
Ethalfluralin, registered under the trade name Sonalan® HFP Herbicide (EPA Reg. No. 10163-356) is used for the control of annual grasses and broadleaf weeds. This product can be applied before planting or after planting but before hemp has emerged. The product needs to be incorporated mechanically or with irrigation. Application rate depends on soil type, with an application rate of 1.5-3 pints per acre. Lower rates should be used in coarse soils. Applicants need to have the supplemental label when applying this product. The supplemental label can be found here and can be used through May 1st, 2026. When using a supplemental label, all applicable directions, restrictions, and precautions on the container label must be followed.
Because ethalfluralin has not been tested on all hemp varieties or on all soil types, it is recommended to test the product on a small area first. There are also restrictions that hemp growers need to be aware of. This product should not be applied to soils that are wet and subject to prolonged flooding and no more than one application per year can be made. Additional restrictions and use information can be found on the supplemental label here.
