Glasshouse and field experiments were conducted on fine sandy loam, sandy clay loam, and clay to study under high temperatures 2-chloroallyl diethyldithiocarbamate (CDEC) and ethyl N,N-dipropylthiolcarbamate (EPTC) incorporated with the surface ½, 1, 2, and 3 in of soil and unincorporated. Herbicides, sprayed on the soil surface, were incorporated either manually in the glasshouse or with a powered, rotary tiller in the field. The principal weed species were Palmer amaranth (Amaranthus palmeri S. Wats.), redroot pigweed (Amaranthus retroflexus L.), junglerice (Echinochloa colonum (L.) Link), and barnyardgrass (Echinochloa crusgalli (L.) Beauv.). Performances of herbicides were determined by counting the plants 2 weeks after treatment.
The herbicidal performance of CDEC was greater when the applications were incorporated with the surface ½ or 1 in whereas the performance of EPTC increased with increasing depths of incorporation up to 3 in. Soil temperature, soil moisture losses, and the distribution of herbicide in soil apparently contributed to differential herbicide performance.