SONAR A.S. herbicide is a selective systemic aquatic herbicide for management of aquatic vegetation in fresh water ponds, lakes, reservoirs, drainage canals and irrigation canals. SONAR A.S. is absorbed from water by plant shoots and from hydrosoil by the roots of aquatic vascular plants. It is important to maintain the recommended concentration of SONAR A.S. in contact with the target plants for a minimum of 45 days. Rapid water movement or any condition which results in rapid dilution of SONAR A.S. in treated water will reduce its effectiveness.

In susceptible plants, SONAR A.S. inhibits the formation of carotene. In the absence of carotene, chlorophyll is rapidly degraded by sunlight. Herbicidal symptoms of SONAR A.S. appear in seven to ten days and appear as white (chlorotic) or pink growing points. Under optimum conditions, 30 to 90 days are required before the desired level of aquatic plant management is achieved with SONAR A.S. Species susceptibility to SONAR A.S. may vary depending on time of year, stage of growth, and water movement. For best results, apply SONAR A.S. prior to initiation of weed growth or when weeds begin active growth.