Abstract
TDW (CABAC)-63, 39 and 43 are selective soil treatment herbicides which have been developed in Japan. The chemical name of TDW is benzyl N, N-dialkyl dithiocarbamate and each alkyl radicals are methyl, ethyl, and isopropyl in TDW-63, TDW-39, and TDW-43 respectively.
These herbicides had no inhibitory activity on germination of weed seeds. In growth inhibition tests, they showed stronger activities on the part of shoots than roots of Gramineceous plants such as rice plants and barnyardgrass. On the other hand, stronger inhibitory activities were observed in the part of roots of broad leaf plants such as Japanese radish than shoots of them. Relationships between the herbicidesabsorption part and the growth inhibitory activity in just germinated plants showed the same tendency in rice plants and barnyardgrass. In the treated shoots and leaves, the injury was most severe, and the shoots and leaves in the treatment of roots was the second.
Soil treatments above seeds were more effective than the treatement just under the seeds. In the soil treatment, the following orders of effects were observed.
Cypraceae>Graminae>Broadleaf weeds Selective properties were observed among gramineceous familiy. The dosage which has herbicidal effects on fingergrass and barnyardgrass did not show any phytotoxicity on rice plants.
