Abstract:

In order to selecte effective herbicides against ragweed, the chemical control abilities of 15 kinds of postemergence herbicides was tested on the seedling and mature stage of potted ragweed. The results showed that 4 kinds of no selective herbicides i.e. Glyphosate, Glufosinate, Paraquat and Hexazinone had superior effect on ragweed control in both stages, but Glyphosate and Glufosinate were more effective to mature plants than Paraquat and Hexazinone. Among 11 selective herbicides, Lactofen, Triclopyr, Oxyfluorfen, Bentazone, MCPA-Na, 2,4-D butylate, Fluroxypyr and Dicamba also had a good control ability to seedling stage of ragweed. However, only Lactofen and Triclopyr showed a perfect effect on mature plants. Thifensulfuron-methyl, Pyrazosulfuron-ethyl and Tribenuron-methyl didn’t show desirable results on ragweed control. It demonstrated that the sensitivity of seedlings and mature plants of ragweed to postemergence herbicides was very different.