| Compared with the traditional chemical pesticides, botanical pesticides have been an important class of novel and effective“green-pesticides”so far because of their lower residue, environmental friendly, hard to cause insecticide resistance and safety to natural enemies of pests. Therefore, more efforts in discovery and development of novel botanical pesticides have continued in recent years in many countries like China. Although a series of commercial botanical pesticides are broadly used in agriculture when present, many underresolved key problems in line with the formulations exist as bottleneck, so the industrialization and commercialization of botanical pesticides have been severely impacted for a long stage. The paper focused on the detection methods for quality control, stabilization and synergistic agents, as well as new formulations of botanical pesticides and so on. The main results are briefly summarized as below:1.In this paper,the GC fingerprint of Lvshen1 made with essential oils was established. In the precision test, the RSD of relative retention time of common peaks were less than 0.061%, and the RSD of relative peak area of common peaks were less than 2.29%, showing that the precision was good.The repeatability showed also good with the RSD of relative retention times and stability not reaching 0.07%, 3.0%, respectively.The HPLC fingerprint of 0.15% Podophyllotoxin ME was established. The precision test showed the RSD of relative retention time was less than 1.00% and the RSD of relative common peak areas was below 0.15%. Meanwhile, the RSD of the relative retention times and stability were lower than 0.20%, 3.0%, respectively, enjoying high repeatability.Bioassay and fingerprint analysis of different formulations were compared between before and after hot storage. Fingerprints of those botanical pesticides with the same effective components but different additives were differed, whreas the decomposition rates of the main-effect were qualified. For those preparations of which the change rate of relative common peak areas were within 5%, the biological activities were invariable. Obviously, it showed significant reduction in activity when the relative common peak areas of some great active components changed a lot .2.The synergism of the mixture Silwet 408 and PBO was significant to the five botanical pesticides: pyrethrin, rotenone, nicotine, toosendanin and podophyllotoxin in this study. The optimum ratio of combination was 4:1. According to the results of laboratory tests and field experiments, the activities of those five kinds of pesticides have been makedly enhanced with 5% of synergists added.3. TBHQ has been selected as a good stabilizer for pyrethrin, rotenone, toosendanin. The photodegradation cycles for all the three kinds of pesticides were found to be effectively extended by adding TBHQ to their solution. The photolysis inhibiton of TBHQ to pyrethrin related well with its concentration: the greater concentration of pyrethrin, the stronger inhibitory effect. The toosendanin (EC) after adding 2%TBHQ was steadily increased to a certain extent, and the half-life degradation extended 0.44 day.4.The inclusion complex of the wintergreen oil HP-β-CD has been prepared by using saturated solution method. The optimal conditions was got through the orthogonal test: the mass ratio of HP-β-CD and wintergreen oil was10:1, the inclusion time was 2 h, the inclusion temperature was 45℃. The formula of inclusion complex agent was 40% the wintergreen oil HP-β-CD inclusion + 10% surfactant (Nong Ru 600: BY-125 = 1: 1) + 5% ammonium sulfate, and water added to 100%. After formulated, every property indexes of the product were up to standard. Field test results showed that 40% wintergreen oil HP-β-CD agent had good control effect on Macrosiphoniella sanborni, and the rapidly available was slightly lower than the EC, but its persistence was superior to EC. The control efficiency was 98.34% after spraying 5 days, and maintaining above 90% after 7 days.Using saturated solution method, this study has prepared inclusion complex of the toosendanin HP-β-CD. The optimal conditions were as following: the mass ratio of HP-β-CD and toosendanin was 3:1; the inclusion temperature was 60℃; the inclusion time was 12 h. The formula of soluble powder was 40% of the toosendanin HP-β-CD inclusion + 3% of wetting dispersant (NNO:DW200=5:2) + 57% of silica. 40% toosendanin HP-β-CD soluble powder was found to be more effective against the Cabbage Butterfly (Pieris rapae L.), with the weak rapidly available and increasing persistence in field experiments. The control effect of preparations, diluted 1000 times, maximumly reached to 98.34% after 7 days spraying, and maintaining above 95% after 11 days. Apparently, toosendanin showed slow release feature after included by HP-β-CD.5.Several key factors related to In-Situ polymerization in preparing the wintergreen oil micro-capsules have been investigated. The optimized parameters were discussed and presented: m(core material)∶m(outer material )= 1:1, 3.0% of SMA: Tween80 = 1:1 mixture as encystatal promoter, emulsification rotate speed 800r/min, acid preparing rotate speed 400r/min, emulsification and acid preparing temperature 30℃, the time of acid between 90 to 150 minutes, acid pH about 2.0, curing temperature 65℃, curing time 90 minutes, pH adjusted to 7.0 after the end of curing. Under these conditions, average diameter of wintergreen oil microcapsules was about 7.5μm, and the drug loading of microcapsule was about 40%, the encapsulation efficiency was above 95% in addition. Field tests showed that of 20% of the wintergreen oil microcapsule suspension had high and persist control effects on Macrosiphoniella sanborni .6.The combination of essential oils (turpentine: wintergreen oil = 6:4) was screened as a kind of environmental friendly botanical insecticide. In the lab toxicity tests, insecticidal activity of those botanical insecticide emulsifiable concentrates(EC) can be improved significantly based on the selected plant essential oils. Field experiments showed that, when essential oils were solvent, all the environment-friendly(EC) of pyrethrin, rotenone, nicotine, toosendanin, and podophyllotoxin were more active and effective to tobacco aphid compared with the same amount of xylene as the solvent. Take 2% rotenone(EC) as example, the control effect on hawthorn spider mite (Tetranychus viennensis Zacher), maximumly reached to 93.41% with 800 times dilution and after 7 days, which is similar to the control, 1.8% avermectin in 3000 times.7.Podophyllotoxin microemulsion, 10%ethanol extracts content of Sabina ,has been prepared successfully, throughout the screening of solvent, emulsifier, cosurfactant, water and the transparent temperature range regulation. According to the quality, laboratory and field tests, this preparation was stable and all the technical indicators met the requirements of microemulsion, with good biological activity to diamondback moth (Plutella xylostella(L.)) and cabbage caterpillar (Pieris) .Many key technologies were studied so far in botanical pesticide production: Combining chromatographic fingerprint with bioassay technologies in order to control the quality of formulation products, reasonable use of synergists and stabilizer to extend the persistent period and control effects, and choosing appropriate drugs and environmental solvents according to the characteristics of raw pesiticide . |
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