Study On The Pesticedal Microemulsion And Mixture Formulation Of Podophyllotoxin

Sabina vulgaris is a potenial insecticidal plant,in which the podophyllotoxin is the maincompound with insecticidal activity. Many studies with the plant and the Compound havebeen conducted, but there are not any podophyllotoxin-based formulations. Therefore,basedon structure theories of micro-emulsion (ME), the podophyllotoxin-based micro-emulsifier(PBME) was successfully developed.The results are reported as follows: Firstly,a measured up podophyllotoxin ME whose transparent temperature range is -3～62℃was obtained by providing an inert matrix composition comprising a defined mixture ofa nonionic surfactant(DBS-Ca) and an anionic surfactant,mixing with the extract ,organicsolvents ,co-solvent or co-surfactant,and diluting with water to form a microemulsionconcentrate.The quality test showed that the formulation is eligible .The results of field trialsshowed that the Pieris rapae L.could be effectively controlled by spray a 250 fold dilution of0.15% podophyllotoxin ME.According to the related universal standard of pesticide,thequality indexes for 0.15% podophyllotoxin ME were established. Secondly,a HPLC analytical method for podophyllotoxin in the ME has been established,of which the standard deviation, coefficient of variance(CV) and average recovery was0.001581, 1.04％ and 99.3％ respectively. Thirdly, based on the extensively screening of being mixed with 11 kinds of organicinsecticides,a mixture —1.15% podophyllotoxin-cyhalathrin ME was born with highbioactivity.The mixture showed remarkable synergic bioactivity against P. xyloste in thelaboratory condition, whose co-toxicity coefficient(CTC) was 154.17. The result of field trialsshowed that the Pieris rapae L.could be effectively controlled by spraying with a 1500 folddilution of 1.15% podophyllotoxin-cyhalathrin ME. As a competitive new product,the patent has been applied.