A Comparison of Aerial and Ground Application of 2,4-D, Using Different Formulations and Rates of 2,4-D, and Different Kinds and Volumes of Carrier

In South Dakota several cases of injury to wheat from airplane application of 2,4-D by commercial applicators were reported. Some 120,000 acres of wheat were sprayed in South Dakota by commercial airplane applicators in 1953. Wheat growers, farm advisors, and research workers in weed control could not explain (1) why the injury was so variable in certain wheat growing regions during a given season, (2) why injury was not serious during some seasons and was an important factor in reduction of yields in others, (3) the conditions under which the injury occurred, (4) why no damage to wheat was reported from ground spraying, and (5) how injury might be prevented. Thus an investigation was begun in 1952 in South Dakota to answer these questions. This study is a continuation of that investigation. Since very little research data concerning serial application were available, it seemed that present recommendations should be reviewed in order to determine the cause of such damage and perhaps the need for separate recommendations for ground and serial spraying. Research and practical information presently available can be used to make predictions of the probable extent of drift based on such factors as nozzle design, pressure, temperature, wind velocity, etc. However, no simple regulation has been formulated which will insure complete freedom from drift damage an still permit unrestrained us of 2,4-D. Specific information is needed in treating our type of crops for the type of problems which we encounter