Herbicide Protectants and Antidotes — A Review

Herbicide protectants can be used to allow increased herbicide doses without injury to the crop or the use of more potent herbicides to obtain a wider spectrum weed control, longer weed control or greater reliability. They may also allow cheap herbicides to replace more expensive ones. The possible uses of activated charcoal are reviewed and the more specific new chemical antidotes R 25788 (N,N-diallyl 2,2-dichloroacetamide) and NA (1,8-naphthalic anhydride) are described. R 25788 is commercially available in mixture with EPTC and with butylate. The mixture with EPTC is used particularly for the control of shattercane (Sorghum bicolor) in maize. NA can be used as a seed dressing to protect a slightly wider range of crops including sorghum, rice and oats and has made it possible to control wild oats (Avena fatua) in oats and wild rice (Oryza punctata) in rice. Other possible uses are indicated and modes of action discussed.