The Effects Of Three Kinds Of Herbicides On The Growth And Physiology Of Poplar Seedling

Haloxyfop,Fenoxaprop and Atrazine are three common nursery herbicides. In this paper, we studied poplar seedling by measuring chlorophyll content, photosynthetic characteristics, peroxidase activity and MDA contents combined with the index of growth quantity under three concentrations. The results showed that:Photosynthetic rate, growth quantity chlorophyll contents generally declined and effect was evident by 5% when concentration of Haloxyfop was 3.2ml/l. Below 1.6ml/l, the influence was low. Peroxidase activity was evidently inhibited when concentration of Haloxyfop was 3.2ml/l, 1.6ml/l, Peroxidase activity was improved. 3.2ml/l, MDA was accumulated markedly within 2-20 days after herbicide and accumulated within 5-15 days while 1.6ml/l. 0.8ml/l, within 5-10 days.Fenoxaprop had influences on every poplar indexes the 10th day after herbicide treatment. For example, the decline of chlorophyll contents, the reducement of photosynthetic rate, the descend of peroxidase activity, the accumulation of MDA, but duration was very short. Differences between three treatments and comparison were not evident on the whole.Atrazine apparently inhibited growth quantity and photosynthetic rate. When concentration was 3g/l or 2g/I, influence was evident at the level of 1%, lg/1, at the level of 5%. But the influence on chlorophyll contents was generally small. Three treatments of Atrazine can all apparently inhibit peroxidase activity and bring about accumulation of MDA.The results of experiment indicate Haloxyfop of high concentration can inhibit the growth of poplar seedling and we should control concentration below lg/1 when use in nursery. Fenoxaprop have small influences on poplar seedling and we may use it safely below 4g/l. Atrazine can strongly inhibit poplar seedling even if concentration is lg/1, so we should avoid using it as treatment solvent to stem and leaf after seedling in instant poplar nursery.