Bioassay For Herbicidal Activity Of New Compounds P0603 And P0406

P0603 and P0406 are two new carbamate herbicidal compounds exploited by Xi'an Modern Chemistry Research Institute. In this project the herbicidal characters of P0603 and P0406 were studied by approach of laboratory and field experiments. Their herbicidal activity, controlled weed spectrum, crop safety, were revealed. It provides academic foundations for the commercial development and safe, scientific application of P0603 and P0406. The results are brought forward as following:1. P0603 and P0406 can kill broad-leaved weeds and some grasses effectively,and they can be applied to broad-leaved weeds during the whole vegetate period. As to gramineal weeds, P0603 and P0406 are active when sprayed at 4～8 leaf stage. The herbicidal efficacy of P0603 and P0406 is better than Asulam but worse than MCPA-NA. P0603 is more efficacious than P0406.2. In field trials, P0603 at 2.0～7.5 kg a.i./hm2 provided excellent control(>80%) of the common weeds:Capsella bursa-pastoris (L.) Medic.,Duchesnea indica (Andrews) Focke,Lagopsis supina (Steph.) Ik.,Cerastium arvense L.,Tonilis scabra (Thunb.) DC.,Veronica didyma Tenore,Dicranostigma Leptopodum(Maxim.)Fedde,Descurainia sophia (L.) Schur.,Chenopodium album L.,Humulus scandens (Lour.) Merr.,Artemisia sacrorum Ledeb.,Cyperus rotundus L.,Bothriospermum chinense Bge.,Galium tricorne Stokes,Conyza canadensis(L.) Cronq.,A. annua L.,Trigonotis peduncularis (Trev.) Benth.,Euphorbia helioscopia L.. P0406 applied at 2.0～7.5 kg a.i./hm2 can control against C. album L.,H. scandens (Lour.) Merr.,A. sacrorum Ledeb.,B. chinense Bge.),G. tricorne Stokes,C. canadensis(L.) Cronq.,A. annua L.,T. peduncularis (Trev.) Benth..3. Pot experiments showed that the usage dose of P0603 and P0406 should be above 2.0 kg a.i./hm2, and that soil application is a preferable method with higher weed control efficiency than foliar application.4. Below the dose of 4.0 kg a.i./hm2 and 2.0 kg a.i./hm2, P0603 foliar applied is respectively safe to wheat (Triticum aestivum L.) and maize (Zea may L.). But even when the dose is 1.0 kg a.i./hm2, it severely injured dicotyledonous crops like clover (Medicago sativa L.), oilseed rape (Brassica Rapus L.) and tomato (Lycopersicon. esculentum Mill.). The top proper concentrations of soil applied P0603 to wheat and maize are both under 4.0 kg a.i./hm2. P0406 do no harm to wheat if sprayed at 2.0 kg a.i./hm2 while injured oilseed rape, cabbage (B. pekinensis Rupr.) and maize. P0406 cannot be used as soil treatment herbicide to wheat and oilseed rape.5. P0603 sprayed at dose of 2.0～4.0 kg a.i./hm2 and 2.0 kg a.i./hm2 can be used for weeds control in wheat and maize field respectively. The suitable application time for wheat is 4 leaf stage and for maize is 4～5 leaf stage. When P0603 applied before seedlings, it is safe to wheat and maize at dose under 5.0 kg a.i./hm2. P0406 foliar applied in is only safe to wheat at dose of not higher than 2.0 kg a.i./hm2.