Studies on Sensitivities of Different Isolates of Botryosphaeria dothidea from Different Regions to Various Fungicides
7 isolates of Botryosphaeria dothidea were isolated and purified from apple fruits and xylem of cherry stem,and the mycelia growth-rate method was employed to determined the toxicity of 6 fungicides to these isolates.Results showed that toxicities of tested fungicides from the biggest to the smallest were fludioxonil,tebuconazole,thiophanate methyl,difenoconazole,pyrimethanil and azoxystrobin respectively.Different isolates showed different sensitivity to the fungicides.All isolates were sensitive to fludioxo nil,tebuconazole,thiophanate methyl relatively,and the value of EC50 of all isolates was lower than 1 μg/mL,the toxicity of the 3 fungicides to the most sensitive isolates was 7.5 times、13.67 times and 9.14 times respectively compared to the most tolerant isolates.All tested isolates showed a little bit lower sensitivity to difenoconazole than the 3 fungicides mentioned above,the value of EC50 was between 0.51～2.27 μg/mL.Pyrimethanil and azoxystrobin showed lower virulence to the 7 isolates,and can not be used as a fungicide to control apple ring rot disease.Only isolates 1010 looks like more sensitive to pyrimethanil,the EC50 value is 0.02 μg/mL,but the slope (b value) of the toxicity regression line is too moderate,so the EC95 is up to 2.95 × 104 μg/mL,and this fungicide also lost the value of practical application.
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NSTL
万方数据
维普
