Evaluation Of Pesticide Activity Of Crude Extracts Of 143 Plants In Qin Ling Region

Finding botanical activity compounds is an important basis to develop new botanical pesticides.In this research we screended the insecticidal,antifugal and herbicidal activity of 143 plants in Qinling area so as to find new plants having the potential to be developed into botanical pesticide.The main results are as follows:1.The antifeedant and toxic activity of crude acetone extracts(1 gDW/ml)of 143 plants were evaluated against the 3rd larva of Mythimna separata by leaf-dipping method.The results showed that 73 of the 143 plants possessed antifeedant or toxic activity against the 3rd larvae of Mythimna separata with the antifeedant(24h)or mortality(72h)activity of over 50.0%.Thirteen Latin Name with higher inGecticidal activity were further assessed against 3rd larva of Mythimna.Of the thirteen plants,Alangium chinense(Lour.)Harms,Juglans nigra Ait.and Daphne genkwa Sieb.et Zucc.showed obviously insecticidal activity against the 3rd larvae of M.separata.2.Diet-incorporation method was used to determine the population-inhibiting activity of crude acetone extracts of 143 plants against Sitophilus zeamais.The extracts of thity-three plant showed good population-inhibiting activity at the concentration of 0.013gDW/g,with the inhibitory rate(64d)of more than 50.0%.Alangium chinense(Lour.)Harms,Euonymus schensianus Maxim.and Scutellaria baicalensis possessed the strongest population-inhibiting activity with the inhibitory rate of 100.0%.3.Growth rate method was used to evaluate the antifugal activity of 143 plants against Botrytis cinerea,FusaHum graminearum Sehw,Thanatephorus cucumeris and Phytophthora capsici.The results showed that twenty five plants possessed inhibition rate of over 80%against at least one of the four fugus at the concentration of 0.1 g DW/mL,which acconnted for 17.6%of all the plants tested.Hypericum monogynum L.and Alangium chinense(Lour.)Harms had a strong inhibition activity against these four fugus.4.Seed germination method was used to evaluate the herbicidal activity of 143 plants against Triticum aestivumLinn.,Cucumis sativus Linn and Lactuca sativa.The results showed that seventy percent of the plants tested had a high inhibition rate(over 70%)against the three botany after three days.Sapindus mukorossi Gaertn.,Symphoricarpos sinensis Rehd.,Pterocarya insignis and Adinandra millettii(Hook.et Arn.)Benth.et Hook.f.had a high inhibition activity after fifteen days.