Efficacy of weed control measures and soil persistence of atrazine in sugarcane (Saccharum officinarum) as influenced by irrigation and nitrogen

The results of the field experiment conducted at Lucknow from 1994 to 1996 revealed that varying levels of irrigation and nitrogen as well as differen t weed control measures significantly affected the weed growth and the yiel d attributes and yield of sugarcane (Saccharum officinarum L.). The highest cane yield (77.1 tonnes/ ha) was obtained with atrazine + 2,4-D + 1 hoeing treatment, however, the benefit : cost ratio (1.69) was highest with the u se of chemicals alone. Juice quality remained unaffected due to various tre atments. Significant increase in nitrate reductase activity due to weed con trol measures was also observed. Atrazine persisted in soil varying from 45 to 60 days and its content declined with increasing moisture and nitrogen levels.