chemical weed control, weed control, herbicides, agronomy
Clean seed, proper seedbed preparation, good crop rotations, and sounds soil management practices are the most reliable procedures for the control of weeds. They will eliminate many annual weeds and prevent infestation by most perennial weeds. Chemicals have proved to be valuable supplements to these practices. However, too many people rely on 2,4-D and, at least partially, neglect the standard practices. Consequently, weeds resistant to 2,4-D are allowed to spread. Once weeds become established, special practices are needed to eliminate them. These practices include the use of special cultivation, competitive crops, and chemicals in addition to the old reliable methods already mentioned. One application of any one of the practices seldom eliminates all perennial weeds. Even though top growth is eliminated, new weeds come from the seeds in the soil. Some of these seeds remain viable for as long as 20 years and many years of diligent work are required to eliminate them. The major portion of this circular is devoted to a discussion of research results obtained in South Dakota and neighboring states. The discussion of special cultural and chemical practices in concerned primarily with the control and elimination of weed infestations. It does not dwell on practices needed to prevent reinfestation of areas on which weeds have been eliminated.
South Dakota State State College of Agriculture and Mechanic Arts, Agricultural Experiment Station
Derscheid, L. A. and Wallace, K. E., "Weed Control Research in South Dakota" (1956). Agricultural Experiment Station Circulars. 119.