Comparative Effects of Three EPTC Antidotes

In growth room studies, N,N-diallyl-2,2-dichloro- acetamide (hereafter referred to as R-25788) was the most effective of three antidotes for the reduction of EPTC (S- ethyl dipropylthiocarbamate) injury to corn (Zea mays L. 'United Hybrid 106'). R-25788 reduced EPTC injury to corn as a seed treatment, as an incorporated soil spray, or in nutrient solution in quartz sand nutrient culture. CDAA (N,N-diallyl-2-chloroacetamide) was also an EPTC antidote for corn when applied to the soil or in nutrient solution but was itself toxic to corn when applied as a seed treatment. The antidote 1,8-naphthalic anhydride (hereafter referred to as naphthalic anhydride) was less effective than R-25788 as a seed treatment and was ineffective when applied to the soil. Naphthalic anhydride was the only one of the three antidotes which also reduced EPTC toxicity to green foxtail (Setaria viridis (L.) Beauv.).