Study On The Preparations Of Psoralea Corylifolia L. Seed Extracts As A New Botanical Fungicide

Psoralea corylifolia L.is an annual herb,the extracts of Psoralea corylifolia L.seed has inhibitory effects on various phytopathogenic fungus such as the pyricularia oryzae Cav.Comparing single factor experiment,the best formula of extracts of Psoralea corylifolia L.seed suspension concentrate(SC),water dispersible granule(WDG)and microemulsion(ME)were screened,and the optimal processing technology determined;Indoor pot experiment and field trials were used to determine their field efficacy.The main results are as follows:1.An optimized formulation of extracts of Psoralea corylifolia L.seed SC was prepared as follow:Extracts of Psoralea corylifolia L.seed 15%,Assistant A 15%,EL-40 15%and water.Solvent replacement method is the best way to preparation.After testing,the quality is qualified.2.An optimized formulation of extracts of Psoralea corylifolia L.seed WDG was prepared as follows:Extracts of Psoralea corylifolia L.seed 30%,Q303 6.7%,Assistant C 3.3%,Sucrose43.33%,Carbon-white 16.67%.Squeezing granulation method is the best way to preparation.After testing,the quality is qualified.3.An optimized formulation of extracts of Psoralea corylifolia L.seed ME was prepared as follows:Extracts of Psoralea corylifolia L.seed 10%,DMF 20%,Pesticide emulsifier 601~#10%,Assistant D 5%and water.Emulsifying method is the best way to preparation.After testing,the quality is qualified.4.By compared with 75%tricyclazole WP,33%Pyrazole·isoprothiolane EC,40%isoprothiolane EC(Lv Heng),73%amethylamine·pentazole WP,40%isoprothiolane EC(Fuji No.1),2%Chunramycin SL,using indoor pot experiment to determine the preventive effect and therapeutic effect of extracts of Psoralea corylifolia L.seed WDG,SC and ME on pyricularia oryzae Cav.The preventive effect was 41.07%,37.23%,38.22%respectively,and the therapeutic effect was 33.61%,30.55%,23.41%.The effect of extracts of Psoralea corylifolia L.seed preparations was significantly equal to even better than other control agents.The efficacy of WDG was the best,the efficacy of ME and SC was similar.5.Field trials in eight places in two years showed that the control efficacy of extracts of Psoralea corylifolia L.seed ME on the pyricularia oryzae Cav could reach 71%~85%,it is equal to even better than 40%isoprothiolane emulsifiable’s.The phytotoxicity wasn’t found and safe for creatures.Before or in the early stage of the pyricularia oryzae Cav,according to 450~900 g a.i./hm~2 dose,spraying 2~3 times,interval 7~10d.