| 摘要 |
<p>Composition for controlling the growth of aquatic weeds comprises an inert support, in the form a water-in-oil emulsion and a pyridine deriv. of formula (I) and non-phytotoxic acid addition salts. In (I) X is H, OH,halo, 1-3C alkoxy, 1-6 C alkylthio, cyclohexylthio, 4-chlorophenylthio, -N(R3)2, acetamido, imidazo-1-yl, morpholino or cyano, R1 = H, 1-9C alkyl, ethylnyl, 3-6C cycloalkyl, benzyl, phenyl or monohalophenyl, R2 = 1-9C alkyl, 3-6C cycloalkyl, cyclohexylmethyl, cyclohexylethyl, phenyl, mono- or di-halo-phenyl, 3,4-methylenedioxy-phenyl, trifluoromethylphenyl, p-cumenyl, tolyl, phenoxyphenyl, phenoxy-1-4C alkyl, benzyl, 1-4C alkoxy-phenyl, pentafluorophenyl, xylyl, 2-thienyl, 3-pyridyl, 1,3-dioxan-5-yl or 5-methyl-1,3-dioxan-5-yl or R1 and R2 together with the C atom to which they are joined form a 2,6-dimethylcyclohexan-1-yl, 9-fluorenyl, 10,11-dihydro-5H-dibenzo(a,d)-cyclohepten-5-yl, 9-xanthenyl, 5H-dibenzo(a,d)-cyclohepten-5-yl or 9-thioxanthenyl, R3 = H or 1-6C alkyl. (I) are known plant growth regulants but have never been used to control aquatic plants. They are applied in forms which float (to control floating weeds), sink (to control weeds with roots in the immersed soil) or evenly distribute (I) throughout the water. Typical solvents for (I) include citrus terpenes, petroleum distillates and water. The concentration of (I) applied is 0.25-10 wt ppm (pref. 0.25-2 wt ppm). They are used at levels which inhibit the growth of the weeds but do not kill them. Activity tests are described e.g. most of the cpds. give a 75-100% inhibition of the growth of Hydrilla verticillata when used at concentrations of 10 ppm.</p> |
