From 100 to 500 lbs. of Norit A per acre were required for contratoxification of ammonium 2,4-dichlorophenoxyacetate previously applied to a field soil at a rate of 10 lbs. per acre. A cone of a Norit A - soil mixture above seeds, or such a mixture covering a row of seeds, protected germinating plants from broadcast applications of growth-regulators. Effective weed control was obtained in these plots. A cone of contratoxicant 0.5 inch in diam. at soil surface above a seed gave much protection to the germinating seed against a growth-regulator, and a concn. of 1000 ppm. of Norit A in soil was sufficient to furnish much protection. When Norit A was mixed with a field soil, it retained its adsorptive capacity for a growth-regulator for at least 12 days. Coating seeds of Red Kidney bean with Norit A before planting in soil previously treated with a growth-regulator gave partial protection to the germinating seeds. A 5% aqueous suspension of Norit A sprayed on kidney beans and dust applications of activated carbons on soybeans protected the plants from subsequent application of growth-regulators. Unless Norit A was applied within 15 min. after plants were sprayed with growth-regulator, little protection was afforded.