Reference

Selective action of pyrazosulfuron-ethyl on growth and acetolactate synthase activity between rice and Cyperus serotinus

Selective action of pyrazosulfuron-ethyl on growth and acetolactate synthase activity between rice and Cyperus serotinus. Kobayashi, Katsuichiro; Sugiyama, Hirosi (Natl. Agric. Res. Cent., Tsukuba 305, Japan). Zasso Kenkyu, 36(3), 251-6 (English) 1991. CODEN: ZASKAN. ISSN: 0372-798X. DOCUMENT TYPE: Journal CA Section: 5 (Agrochemical Bioregulators) The mechanism of selective action of pyrazosulfuron-Et (I) between rice and C. serotinus was studied. I inhibited the growth of roots and shoots of C. serotinus more severely than that of rice. 93697-74-6 and 9027-45-6 are also in the experiment. I inhibited the activity of acetolactate synthase from several organs of both plants equally, the median inhibitory concn. being about 10 nM. Treatment of C. serotinus with I markedly reduced the in vivo acetolactate synthase, which was hardly recovered afterward, whereas the enzyme activity in rice plants was reduced less than in C. serotinus, and was recovered in 1-2 wk. Results suggest that the primary site of I action is acetolactate synthase and the selectivity is attributable to the difference in the inhibitory effect on this enzyme in the 2 plants. .

Distribution and degradation of pyrazosulfuron-ethyl in paddy field

Distribution and degradation of pyrazosulfuron-ethyl in paddy field. Chu, C.; Lin, H. T.; Wong, S.Chemical with cas number 93697-74-6 also plays role. S.; Li, G. C. (Department of Residue Control, Council of Agriculture, Taiwan Agricultural Chemicals and Toxic Substances Research Institute, Wufeng, Taichung, Taiwan, Peop. Rep. China). Zhiwu Baohu Xuehui Huikan, 44(3), 147-156 (Chinese) 2002 Plant Protection Society of the Republic of China. CODEN: PLPBBH. ISSN: 0577-750X. DOCUMENT TYPE: Journal CA Section: 5 (Agrochemical Bioregulators) Section cross-reference(s): 61 Pyrazosulfuron-Et is a highly active sulfonylurea herbicide and is mainly registered for use in paddy fields in Taiwan. The fate of pyrazosulfuron-Et in flooded soil, water and rice was studied in a semi-open model ecosystem under local conditions. Sirius 10% tablet (contain 9.4% pyrazosulfuron-ethyl) were used for seven days after rice was planted. The water, soil, and rice plants were sampled during rice growing period, and hulled rice sample was analyzed after harvesting. The half-lives of pyrazosulfuron-Et in soil and field water were 16-27 days and 9-16 days, resp. Pyrazosulfuron-Et was stable in rice plant, concns. of pyrazosulfuron-Et in rice plants were higher than those in other environmental compartments. Residue of pyrazosulfuron-Et was not detected in milled rice. .