Study On Herbicidal Bioactivity And Characteristics Of The Novel Compound HIA-1

In order to develop herbicide, improve independent innovation ability and adapt to sustainable development of agriculture, designing and researching new-style herbicide which inhibited pyrurate dehydrogenase complex became a stirring field. In this paper, the novel compound named O,O-dimethyl-1-(2,4-dichloro- phenoxy-acetyloxy)-methylfuran phosphonate was selected as research object. In order to ascertain its application potential to control weeds in corn field, provide theoretical and practical basis for its development and application, and also provide referenced basis for new-style herbicide′s study and innovation, we tested herbicidal bioactivity, spectrum of weed controlling, absorption site, safty to crops, field efficacy trial and so on, researched its mechanism and effect on partial biochemical indexes of plant.The results could be summarized as follows:1. Results of bioassay showed that HIA-1 had dual activity. Radicle and bud were promoted at low concentration, but inhibited at high concentration with different sensitivity to six materials. Thereinto, the dicotyledon such as Cucumis sativus, Raphanus sativus, Abutilon theophrasti and Brassica campestris were more sensitive to HIA-1. The inhibitory rates of radicle and bud length were more than 86.2% and 88.2% at 10mg/L.2. The research of activities which were compared between pre-emergence and post-emergence showed that all the effect of post-emergence treatments were significantly better than pre-emergence treatments. Thereinto, the EC90 of Portulaca oleracea, Amaranthus retroflexus and Abutilon theophrasti after post-emergence treatment were 496.54,399.25,318.50g a.i./hm2, and 3807.41,3912.69,3437.29g a.i./hm2 after pre-emergence treatment.3. Spectrum of weed controlling was carried by pot bioassay in greenhouse. Result showed that HIA-1 had good control effect to mostly familiar latifoliate weeds, and generic control effect to gramineous weeds. Ltifoliate weeds became twisted, malformed and stunted after two days with foliage treatment. Some tumors were appeared after ten days, and the plant became dry rot and dead from tumors. Gramineous weeds behaved stunted, then became pitchy and perished.4. Safty experiment indicated that HIA-1was safe to different varietal corns with almost same sensitive degree. Selectivity indexes were all above 2.6, such as NongDa 108, XianXing 2#, JinHai 604, etal, except TaiYu 14#. Cotton, peanut, soybean and cole were more sensitive with obvious injury as same as weeds′.5. By pot bioassay method in greenhouse, it was found that the sensitivity of material had difference at different leaf-stage. The application timing was from 2 to 3-leaf stage of weeds. And the control effect was more than 90% at 600g a.i./hm2.6. By method of active carbon isolation, foliage treatment and pouring roots, it was found that this novel compound could be absorbed into plant by buds, radicles, leaves, root and stems.7. The study of effect mechanism showed that HIA-1 was pyrurate dehydrogenase complex inhibitor. The inhibitory rate was about 60% at 1000mg/L.8. By Abutilon theophrasti to be material, some biochemical indexes of seedling and radicle such as comparative survival rate of cells, POD activity, SOD activity and root activity had some corresponding changes after treatment with HIA-1. These biochemical indexes were inhibited evidently at high concentrations and inhibited unevidently or activated at low concentrations. The cells comparative survival rate of radicle was above 100% at 0.1mg/L, representing stimulative effect, and lower than 40% at 1000 mg/L. SOD and POD activities showed same change tendency, which were increased first and reduced later. SOD activities of seedling and radicle were about 50% and 30% of control at 1000mg/L. Respectively, with both about 113% of those of the control at 0.1 and 1mg/L. POD activities of seedling and radicle were lower than the control activities from 10 to 1000mg/L, with 58% and 40% of those of the control at 1000m g/L. And the POD activities were both about 130% of those of the control at 1mg/L. The root activity was lower than that of the control with significant defferences.9. The field efficacy trial indicated that 30% HIA-1 EC had high efficacy to control Amaranthus retroflexus, Portulaca oleracea and Chenopodium album, but the general control effect was lower than that of 72%2,4-D butylate. It was safe to corn with slow speed of effect relatively, and better to be used in corn field which had more latifoliate weeds.