Two of the most troublesome weeds in Natal sugarcane fields are the sedges Cyperus esculentus and Cyperus rotundus, known locally as either watergrass or nutgrass. Much of the experimental work conducted with herbicides over the past 18 years has been directed towards the chemical control of these species. McMartin (6) reported that in his early experiments the leaves of both weeds were killed by 4 lb. a.e. 2,4-D per acre, but that regrowth occurred from the underground tubers, and that second and third applications were sometimes necessary. Even then the plants were not entirely controlled. In a subsequent report McMartin (7) stated that pre-emergent applications of 2,4-D reduced the number of nutgrass plants appearing above ground.