Date of Award
Master of Science
Elmer Gray, Edward E.C. Clebsch
To be satisfactory for use in crops a preemergence herbicide must remain active in the soil long enough to provide adequate weed control without persisting long enough to injure succeeding crops. The emphasis in development of herbicides following the advent of 2,4-dichlorophenoxyacetic acid (2,4-D) was to increase persistence to provide full-season weed control. From this effort have evolved chemicals capable of persisting beyond the growing season, possibly injuring succeeding crops.
Since several of the more persistent herbicides used at low rates for selective weed control may be used at high rates as soil sterilants, the persistence and possibility of accumulation of these chemicals in the soil need to be understood. Therefore, a study of the persistence of several preemergence herbicides in the soil was initiated at The University of Tennessee in 1961.
Jones, Larry B., "A three-year study of the persistence of 2,4-D, diuron, simazine, atrazine, DNBP, DCPA, and amiben in the soil. " Master's Thesis, University of Tennessee, 1964.