Thistrol Plus is slow acting and may take several weeks to effect control. The activity of Thistrol Plus depends on its conversion by susceptible weeds from the butyric (MCPB) form to the biologically active acetic (MCPA) form. Treat small seedling or early rosette stage actively growing weeds which are better able to make this conversion. Use the higher rate where weeds are more advanced.
Do not spray weeds under stress (drought, water logging etc.), or if rainfall is expected within 2 hours of application.