Experiments were conducted to studv the comparative efficacy of pre-emergence (to crop) spray of six weedicides viz: s~azin~, atra~ine, prometryne. ametryne. desmetryne and sodium 2. 4-0 each at 3..82 kg./ha for control of weeds in sugarcane and their effects on cane yield and juice quality. Maximum weed mortality was attained under simlzine '(73 6%) followed by atraz lne (69.8%,. There were indications of early disintegration in soil of prometryne, ametryne, and desmetryne. than simazine and atrazine. Germination percentage was not affected but the tillering capacity was favourably influenced by the weedicidal treatments. Height of cane was found to be significantly greater under all the weedicides except 2. 4-0. Hi hest cane yield of 420.2 q/ha. was obtainAd under simazine. followed by atrazine (410.4 q/ha). Difference between simazine and atrazine was not significant. The quality of cane juice i. e. Sucrose and purity percentage was not influenced C1ythe weedicidal treatments.