Determination of the sensitivity of Botryosphaeria berengriana to Carbendazim fungicide.

The sensitivity to carbendazim fungicide of 83 strains of Botryosphaeria berengriana f. sp. piricola collected from apple friut in Shandong province in 2007 was determined with the method of colonial growth-rate. The frequency distributions of EC50 values to the 83 strains of carbendazim were all unimodal and the EC50 values ranged from 0.019 6 mg·L-1 to 0.486 7 mg·L-1 and the mean EC50 values (±Se ×t0.05 )were (0.108 0±0.015 2) mg·L-1. The sensitive baseline of Botryosphaeria berengriana f. sp. piricola to carbendazim was determined as 0.042 8 mg·L-1 based on the mean EC50 value to the most sensitive isolate from Taishan. The results of Duncan test and hierarchical cluster analysis showed that the sensitivities to carbendazim of Botryosphaeria berengriana f. sp. piricola from different regions were in high levels. There was no evident difference in the strains and no resistant subcolony.