Check the listing for details. Imazapyr 4 SL Weed Control - 1 Gallon. Condition: New. Listed at 197.77 USD. ALLIGARE IMAZAPYR 4 SLPre- and post-emergent, non-selective herbicide for control of undesirable vegetation in timber production sites including forest roads and non-irrigation ditch banks. ENVIRONMENTAL HAZARDSThis product is toxic to plants. Drift and run-off may be hazardous to plants in water adjacent to treated areas. Do not apply to water except as specified on this label. Treatment of aquatic weeds may result in oxygen depletion or loss due to decomposition of dead plants. Do not treat more than one-half the surface area of the water in a single operation and wait at least 10 to 14 days between treatments. Begin treatments along the shore and proceed outward in bands to allow aquatic organisms to move into untreated areas. Do not contaminate water when disposing of equipment washwaters or rinsate. See Directions for Use for additional precautions and requirements.