Effect of 1,8-NA and CGA 123'407 on Reducing Herbicide Injury of Rice Plants

Since herbicide damage has been occurred in subirrigated rice seedbed in Korea, the use of crop safener is required to reduce crop injury. Field studies were conducted to evaluate safening effect of 1,8-naphthalic anhydride (NA) and CGA 123'407 (4, 6-dichloro-2-phenyl-pyrimidine) against four kinds of paddy herbicides applied to subirrigated vinyl-covered rice seedbed. NA as a seed dressing at 0.5% (W/W) was effective in reducing rice injury from butachlor, pretilachlor, chlormethoxynil and benthiocarb, and increased number of seedling established, plant height, and dry weight of rice seedlings, while growth inhibition and stand loss were observed at 1% NA. Pretilachlor slightly decreased number of seedlings established and inhibited growth of rice seedlings. But pre-mix combination of pretilachlor (2%) and CGA 123'407 (0.5%) reduced rice injury caused by pretilachlor alone and increased number of seedlings established and dry weight of rice seedlings. The results indicate that NA and CGA 123'407 would permit the safe application of butachlor, pretilachlor, chlormethoxynil, and benthiocarb in subirrigated rice seedbed.