South Carolina Turf and Pest Control Category 3 Practice Test

Postemergence herbicides are applied after weeds have emerged and are actively growing, but they can cause injury to non-target plants if spray contacts green bark or other green tissues. Many of these products are absorbed or translocated through intact plant tissues, so exposure to the bark of desirable trees or shrubs can lead to unwanted damage. This highlights why spray drift control and protecting surrounding vegetation are important when using postemergence products. The other statements aren’t correct: these herbicides are not applied before weeds emerge, they are not limited only to grasses, and there are postemergence products that effectively control broadleaf weeds.