THE RESULTS OF RECENT PRE-EMERGENCE HERBICIDE SCREENING TRIALS IN SUGARCANE, 1970-73 By F. E. RICHARDSON

The results of nine pre-emergence experiments involving fourteen herbicides used alone or in combination are reported. Herbicide effectiveness on sandy and clay soils was compared, and special attention was given to the degree of grass control. Alachlor treatments (Lasso) were consistently satisfactory, with a mixture of alachlor and atrazine (2 kg a.i. + 1 kg a.i./ha) being excellent. Sencor (Bayer 94337) was very promising and is suitable for long-term general weed control (over 12 weeks) on all soils at a dose of 2-3 kg a.i./ha. Bladex (WL 19805) and Upjohn 27267 were also effective in some experiments. A number of products were more effective on sandy than on heavier soils. Most treatments gave over 8 weeks control of annual grasses and broad-leaf weeds, but none were acceptable fqr Cyperus rotundus or C. esculentus control. None of the products adversely affected the sugarcane varieties used in the experiments.