Control Effects Of Clarinet SC On Venturia Nashicola Tanaka Et Yamamoto And It's Application

Venturia nashi-cola Tanaka et Yamamoto is one of the most important diseases in the production of pear,it happened at every pear producing areas in our country.After the pear is infected with Venturia nashicola Tanaka et Yamamoto, it will lead to the results of leaf falle and the fruit abnormality,also it' s production will induce in next year.Experiment was conducted on the control of Venturia nashicola Tanaka et Yamamoto with Clarinet SC 20% in field and toxicity test in the room in 2003.Toxicity test of clarinet was done by the method of mycelial growth inhibi tion.The results showed that probability(y) which comes from the inhibition rates of hypha growth and the logarithmic(x) of active constituent contents (mg/kg) of different fungicides show linearrelation , The regression equation is y=5.3321+ 0.9515x (4 days) or y= 5.3736+0.9736x (6 days) ,EC₅₀ of the clarinet is 0.45 mg/kg(4 days)or 0.41 mg/kg (6days) by the regression equation, and it's EC₉₅ is 23.97 mg/kg (4days) or 20.22 mg/kg(6days) .Contrast with the conventional fungicide, toxicity of the clarinet below the carbendazim in room. Control effect of clarinet SC 20% on Venturia nashicola Tanaka et Yamamoto began from early May (about 1 Odays after anthesis ),spraying once at every 10— 15 days. The results showed that 1000 times or 1200 times or 1600 times as much as Clarinet SC 20% are very effective to Venturia nashicola Tanaka et Yamamoto on leaves or fruits, Their proof rate are about 100%.so we think that Clarinet SC 20% is the best effect to Venturia nashicola Tanaka et Yamamoto , and it should be popularized and applied in the field widely.