The result is the failure of susceptible grass and broadleaved weeds to emerge. The symptoms of injured crop plants such as corn or sorghum are stunted, malformed, and twisted seedlings. Severe leaf distortion is characteristic and the leaves may not unroll normally. Broadleaved crops exhibit crinkled or cupped and thickened leaves. Photodegradation is the main route for field dissipation, especially if Dual remains on the soil surface for prolonged periods without an irrigation or rainfall.
Microbial breakdown is another major route for field dissipation, especially below the soil surface.
Dual in the soil has a half-life of 15 to 25 days based on bioassays and generally should not persist very long in the soil to affect subsequent crops. Dual generally does not leach and when applied to the soil surface should not volatilize unless certain extreme conditions arise. Contact the Arizona Department of Agriculture for further information about obtaining a permit to use Dual herbicide. Herbicide Handbook, Seventh edition. Weed Science Society of America.