Silvex, [2-(2,4,5-trichlorophenoxy)propionic acid], impregnated (20% ae) on clay granules, applied at a rate as low as 20 lb/A ae gave excellent control of well-rooted alligatorweed [Alternanthera philoxeroides (Mart.) Grieb] growing in less than 18 inches of water. The 2-ethylhexyl ester of silvex was more effective than the potassium salt. Silvex was not effective on floating-mat alligatorweed or in water over 18 inches deep.

Cotton plants were treated with C14-ring-labeled 2-methylmercapto-4,6-bis(isopropylamino)-s-triazine (prometryne) which was soil-incorporated or placed in solution cultures. C14-labeled material accumulated in the lysigenous glands of roots, stems and leaves. No evolution of C14-carbon dioxide could be detected. Unaltered C14-prometryne was present in stems and leaves 23 weeks after treatment, but no radioactive materials could be detected in the seed. Small amounts of hydroxypropazine were isolated from the stems and leaves of plants grown in soil, but none was detected in plants grown in solution culture. Both water-soluble and acetone-insoluble radioactive materials accumulated in the leaves, stems and roots of all treated plants.

Diquat (6,7-dihydropyrido[1,2-a:2’,1′-c] pyrazidiinium salt) was applied to several emergent, submersed, floating-leaved, and free-floating aquatic plants common in Central Illinois ponds. At relatively low rates, it was effective in controlling several submersed aquatic plants but not American pondweed, Potamogeton nodosus, and cabomba, Cabomba caroliniana. This herbicide also was effective on several common emergent species.

3-amino-2,5-dichlorobenzoic acid (amiben) and N-1-naphthylphthalamic acid (NPA) were applied to soybeans and 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine) and 2-chloro-N, N-diallylacetamide (CDAA) to corn as sprays and as granules. Except where excellent weed control was established by the herbicides, rotary hoeing 2 weeks after application of the herbicides usually improved the degree of weed control without any detrimental effect on performance of the herbicides.

A chromatographic method with silver nitrate reagent detected dalapon extracted from quackgrass (Agropyron repens (L.) Beauv.) rhizomes. Minimum detectable quantity was 2×10-7 grams. Following field applications of dalapon, the amounts recovered 1 hour after spraying were low for plots receiving 4 lb/A while relatively high amounts were found initially from 8 lb and 12 lb/A treatments, but several days later, these relations were reversed.

The acid and amine formulations of 2,4-dichorophenoxyacetic acid (2,4-D) can be extracted from soybean seed simultaneously or separately. The method consists of partitioning first between ethyl ether and citrate-phosphate buffer and then between carbon tetrachloride and citrate-phosphate buffer. Quantitative determination of the 2,4-D can be made by means of chromatography.