Weed control as we know it today is a new field with frontiers and relationships that have not been clearly charted. Weed control workers are, in a sense, pioneers. The background of knowledge is still not great and many of the questions our farmers are asking have no unequivocal answer. The sources of information are still not clearly defined and many agencies are involved in the search for information. Within any one university or college one frequently finds information that the weed specialist needs developing in the departments of botany, agronomy, vegetable crops, horticulture, chemistry and agricultural engineering. Commercial organizations of many kinds are discovering new facts that we need to know. And not the least of these sources of information is the Extension Service itself because county men, and the farmers they work with, are constantly adding to our knowledge. It is a dull man indeed who can view field after field treated to control weeds without arriving at a good working hypothesis of what can be done and how to go about doing it. The role of the Extension Service in the development of weed control over the past ten years has been overlooked in our emphasis on research. I would not for a moment minimize the importance of the emphasis on research but I do decry the lack of parallel emphasis on encouraging the use of the knowledge so developed. And the Extension Service in the many states has been a potent force in developing the new information credited to research.