Abstract
1) Inhibitory activity on the seminal root elongation of rice and barnyardgrass seeds by CIPC (isopropyl N-(3-chlorophenyl) carbamate) was seventy times stronger than that of MCC.
2) MCC showed the greatest herbicidal activity within the group of methyl N-(mono or di- substituted phenyl) carbamates. Although CIPC and MCC possess the excellent herbicidal properties; the compounds which exchanged their chlorine-substituted phenyl rings each other, isopropyl N-(3, 4-dichlorophenyl) carbamate and methyl N-(3-chlorophenyl) carbamate had very low phytotoxicity in both the soil and foliage application.
3) The rice plants before the 1st leaf stage were not so influenced by MCC absorbed through only the roots under soil culture, but were most susceptible from the 2nd to 3rd leaf stage. This tendency was the same as in the case of foliage application.
4) The effects on the rice plants of MCC were increased by adding of a little amount of carbaryl (NAC, 1-naphthyl N-methylcarbamate) under solution culture, but this synergistic action was less than that of propanil (DCPA). The synergism was not found at the germinating stage.
