After 10 months, diphenamid residues were found throughout the 0–9 inch soil depth. In silt loam soils under climatic conditions prevailing in and around the bluegrass region of Kentucky, diphenamid residues in soils may be present at phytotoxic levels in the plow layer 10–11 months after application at rates required for weed control in tobacco.

If there was no heavy rainfall or surface irrigation before corn emergence, as ethyl-N,N-di-n-propylthiolcarbamate (EPTC) at 3 lb/A was incorporated deeper into the soil, more corn plants were injured, the height of plants was reduced, and a loss in weight or yield occurred, although the germination of the corn seed was not affected. Implements used to incorporate EPTC did not produce significantly different amounts of corn injury where used at the same depth.

Dimethylarsenic acid (cacodylic acid), 2-methoxy-3,6-dichlorobenzoic acid (dicamba), 2,6-dinitro-N,N-di-n-propyl-alpha-alpha-alpha-trifluoro-p-toluidine (trifluralin), and O-(2-4-dichlorophenyl) O-methyl isopropyl-phosphoramidothioate (DMPA) were tested to determine if they could selectively control nimblewill (Muhlenbergia schreberi J. F. Gmel.) in Kentucky bluegrass (Poa pratensis L.) pasture. DMPA reduced the nimblewill population 95% during the initial year of treament, while other herbicides gave only 61 to 72% reduction. No effect on nimblewill was evident the second year after application. None of the herbicides caused severe or permanent injury to the bluegrass.