Study On Soil Fumigant Formulations About Horseradish Essential Oils

The biological fumigation activity about Allyl isothiocyanate to storage pests,fungi, bacteria and nematodes is very strong.However,because of small molecular weight, chemical properties lively,highly volatile and irritating at normal temperature,it is inconvenience to use.Therefore,this paper study on soil fumigant formulations of AITC.The use of molecular inclusion legitimate network,we produced AITC microcapsules(AITC-β-CD complex),and through further optimization of the pilot test methods,the utilization rate of AITC can be increased to 80%.Its release rate increased with increasing relative humidity,and with the extension of storage time,the release rate has gradually slowed down,120h after AITC-β-CD complex were contentting maintained at 32,42,56 and 64μL/g.The Fumigation effects of AITC micro-capsules on Meloidogyne sp.indicate that:over time the mortality rate of nematodes increased rapidly,after 72h the mortality rate the increased about 30%～40%than after 24h;The median lethal concentrations of Meloidogyne sp.were 35.00μL/L,20.93μL/L and 5.26μL/L,which after fumigated 24h,48h and 72h.We used the AITC micro capsules to fumigate the soil directly,and the bioassay results showed that:When the concentration of 25 mL/kg the inhibitory rate was more than 80%to plant pathogenic fungi,which mainly of Fusarium oxysporum.Inhibitory known by the statistical analysis,the EC₅₀ was only 11.97μL/kg.AITC-β-CD complex effect on the bacteria less,the EC₅₀ was 21.80μL/kg.This paper studied on capsules too.In accordance with the storage and use requirements of pesticides,and taking into account the quality of medical capsule evaluation criteria(Chinese Pharmacopoeia 2000 Edition) established the capsule quality standards.Through screening the main shell materials of the capsules,has identified the following five kinds of shell capsule formulations.The ratio of the main materials are as follows:35%gelatin+3%glycerol,30%gelatin+2%polyethylene +3%alcohol glycerol,35%gelatin+1%CMC-Na +3%glycerol,30%gelatin +10%+3%glycerol and 30%gelatin+1%agar+3%glycerol.The other was the safety test of 20%AITC oil and capsules on cucumber and tomato seedlings.The results show that:When AITC concentration was 50μL/kg and 150μL/kg,AITC capsules on cucumber and tomato seedlings were relatively safe.While AITC concentration was 150μL/kg,AITC oil had a slight injury of two.In addition,the pot experiment results about 20%AITC capsules and oil controlling cucumber and tomato root-knot disease showed that:20%AITC capsules and oil capsules on the root-knot nematode disease of tomato and cucumber have good control effect,the results show that:Both of the root-knot nematode disease of tomato and cucumber had good control by 20%AITC capsules and oil.When the concentration of AITC was 50μL/kg,the disease control effect of cucumber and tomato were between 56%～74%,significantly better than the 20%Pharmacy(the concentration was 40mg/kg, control effect was 16%～68%).