Selective pre-emergence herbicide. Prepn: P. C. Hamm, A. J. Speziale, US 2863752 (1958 to Monsanto). Activity studies: Duke, Diss. Abstr. B 28, 1315 (1967); Jaworski, J. Agric. Food Chem. 17, 165 (1969); Lamoureaux et al., ibid. 19, 346 (1971); Dhillon, Anderson, Weed Res. 12, 182 (1972). Metabolism: J. E. Bakke et al., Science 210, 433 (1980). Toxicity data: E. E. Kenaga, Down Earth 35, 25 (1979).