Abstract:

The bioactivity and effect of 18% 2,4-D ME against Mikania micrantha were investigated through the potting and field tests in this paper, which was helpful for screening more effective herbicides against this species of alien invasive weed. The value of ED90 inhibited 90% of M. micrantha growth was calculated through the measurement of inhibition rate in the potting test, and the coverage control and fresh weight effectiveness was calculated to indicate the effect of 18% 2,4-D ME under field condition. The results of potting test showed that ED90 value in the 30th day was 125.9 mL/667 m2, which indicated 18% 2,4-D ME restrained the growth of M. micrantha’s stem and leaf, and ED90 about M. micrantha fresh weight of overground part and roots were 99.3 mL/667 m2 and 141.3 mL/667m2, respectively. The results in field experiment showed that the coverage control effects were more than 90% against M. micrantha after 15 and 30 days treatment with 18% 2,4-D ME from 60 to 180 mL/667 m2, which were significantly higher than that of 70% sulfometuron methyl WP in 262.5 g a.i./hm2, and were more than 90% after 45 days treatment with 120, 180 mL/667 m2 of 18% 2,4-D ME, which had no significant difference with that of 70% sulfometuron methyl WP in 262.5 g ai/hm2. All these results indicated 18% 2,4-D ME in this test had obvious choice on M. micrantha, which could kill M. micrantha and protect other weeds. The tested 18% 2,4-D ME could deserve to be applied to control M. micrantha in forest land, non-cultivated land and urban green land to protect and recovery of the ecological environment damaged by M. micrantha.