Organic Phosphorus Key performance features. These amino acid inhibitors are applied only postemergence. Roundup and Touchdown generally control annual and perennial grasses and broadleaf species. They are non-selective and will kill any living plant tissue they come in contact with. They persist in the soil for more than 200 days, although they are not effective for weed control.
Sunlight plays a minor role in herbicide losses.
Soil adsorption plays a major role in herbicide tie-up, but its composition is relatively unimportant. When these herbicides come in contact with soil, they are inactivated and not effective for weed control. Plant injury symptoms. Some deformation of new growth can occur. These herbicides exhibit foliar activity only.