Research On The Occurrence Mechanism,Forecasting Mechanism And Control Technology Of White Rust(Albugo Ipomoeae-aquaticae) On Ipomoea Aquatica

Ipomoea aquatic Forsk is one of the most important vegetable varieties in Shanghai area,in order to ensure supply of summer vegetable.It has a lipid-lowering diet,heatstroke antipyretic,rich crude fiber and high nutritional in good health care.It is liked by the general public in recent years.White rust covers a cultivated area of 1000~1200 hectares each year in Shanghai.Since Albugo ipomoeae-aquaticae has already become one of the most significant diseases for White rust,and for the sake of safety production and white rust prediction,we researched the occurrence regularity,forecast and control technique of White Rust on Ipomoea aquatica,and come up with these conclutions.First,the optimum prevent time should be the one tip three-leaf period.As for the 10 day average,when the starting temperature is about 20?,the amount of rainfall is over 20 mm,and the sunshine duration is less than 50 hours,this disease happens for the first time in spring.When ten day average temperature is between 23 and 27?,the amount of rainfall is over 50 mm,the sunshine duration is about 40 hours,this disease happens for the most time.When ten day average temperature drop down to 20?,it became less popular.When the ten day average temperature is lower than 18?,it came to the end period.Second,we simplified the forecast research standard and built up a alarming model: y=28.35803216-45.34720997X2+1.4240780279X1*X1+65.42430297X2*X2-0.021827921379X3*X3-19.370678883X1*X2+1.4118118756X2*X3(R2=0.9607).the predicted average fitting degree reached 97%.Third,we screened the most stable,efficient,low-poison degree of some kind of pesticide products.In good weather condition,we recommend to use CuiZe(300g/ml Kresoxim · Boscalid SC).This article can be applied to guide field production,and this will decrease the yearly protected area by 70% and increase the Ipomoea aquatic yield by 15%~30%.