SPECIAL NOTE 



Research in the field of weed control with chennicals is conducted 

 by the United States Department of Agriculture, State agricultural 

 experiment stations, and industrial organizations. Representatives of 

 these groups meet periodically in four regional conferences to discuss 

 research developnnents in the field of chemical weed control and to 

 formulate suggestions on control practices. Some of the suggested 

 weed-control practices of the conferences are summarized in this 

 report in order to make them generally available to agricultural 

 workers in the various States who advise with farm people. 



The effectiveness of herbicides is influenced by soil type, tennpera- 

 ture, rainfall, and other soil and climatic factors. Because of this, the 

 suggestions in this report should be evaluated in terms of local condi- 

 tions and local experience. In a specific State, the recommendations of 

 the agricultural experiment station and the agricultural extension serv- 

 ice should be foUow^ed. Where such recommendations are not available, 

 the suggestions of this report should be looked upon as a general guide. 



All chemicals included in this report, especially -when used on raw- 

 agricultural crops as defined under Public Law^ 518, should be applied 

 in accordance with the directions on the manufacturer's label, as 

 registered under the Federal Insecticide, Fungicide, and Rodenticide 

 Act, as to the crop specified, in the amounts specified, and at the 

 times specified. 



Section I presents information on (1) the physical and chemical 

 properties of all herbicides referred to in this report, (2) oral toxicity 

 of the herbicides to -warmblooded animals, (3) promising new experi- 

 mental uses for existing herbicides and (4) promising experinnental 

 uses for new herbicides. 



The ne-w nnethods and new herbicide uses described in Section I 

 are intended to show progress in the field of weed research. They should 

 not be construed as recomnnendations for weed control in the crops 

 specified, as evidence has not been developed to prove that they will 

 leave no herbicide residues and/or tolerances have not been set under 

 Public Law 518. 



Section II provides infornaation on (1) the manufacturer's method 

 of indicating active ingredients in herbicide formulations, (2) a method 

 of selecting appropriate herbicides for specific areas of use, (3) a 

 nnethod for calibrating herbicide spray equipment, and (4) the effect 

 of climate on the performance of herbicides. 



Sections III through IX contain information which can be used as a 

 guide in the development of recommendations for use of herbicides to 

 control weeds in crops and non-crop' land areas. All of the suggested 

 uses have been registered prior to Feb. 1, 1961, under the provisions 

 of the Federal Insecticide, Fungicide and Rodenticide Act. 



Since the status of chemical weed control is changing rapidly, and 

 herbicide materials or new uses for older ones are being recommended, 

 it is important to keep in touch with the U.S. Department of Agriculture, 

 State agricultural experiment stations, or manufacturers of specific 

 products for up-to-date infornaation. 



