| In order to select effective and secure herbicide to control mikania Micrantha at different growth stages of M.micrantha, four pyridine herbicides, 24% picloram AS (1 125~3 375 mL/hm2), 48% triclopyr EC (3 750~6 255 mL/hm2), 75% clopyralid SGX (134~240 g/hm2) and 20% fluroxypyr EC (750~1 050 mL/hm2) was tested for the effectiveness to control M. micrantha at seedling stage, middle growth stage and adult stage with the control of 41% glyphosate AS (2 250~9 000 g/hm2). After the test, the beans, cabbage, cucumber was planted in the soil sprayed four pesticides and observed their growth status to determine whether the residual damage of four pyridine herbicides occurred. Results showed picloram,triclopyr and fluroxypyr had good control effects on M.micrantha at different growth stages and the stem (or coverage) control
effects and fresh weight control effects on M.micrantha of these three herbicides could be more than 90%. The control effects on M. micrantha of picloram and triclopyr were similar with that of glyphosate at seedling stage and middle growth stage and were better than that of glyphosate at adult stage. Picloram and triclopyr have good control effects to M. micrantha and could instead glyphosate in certain habitats. Due to the long residual of picloram in the soil, it should be used in the agricultural area with caution. |
