Resistance of Botryodiplodia theobromae to Carbendazim and the Fungicides Screening for Mango Stem End Rot Control

86 isolates of Botryodiplodia theobromae Pat., causing mango stem end rot, were obtained from 3 regions in Hainan province of China and tested for their resistance to carbendazim (MBC) in laboratory. The toxicity of 23 fungicides to 2 isolates of carbendazim-resistant and 2 isolates of carbendazim-sensitive B. theobromae was tested by mycelium growth rate methods, and analyzed by the EC50 value, the EC90 value and the cross-resistance to each other. The results showed that the carbendazim-resistant isolates had been found in Danzhou, Ledong and Sanya, Hainan province. 10 fungicides including sporgon, propiconazole, flusilazole, prochloraz, iprodione, difenoconazole, tebuconazole, myclobutanil, pyraclostrobin and validamycin A were recommended for choices for controlling mango stem end rot disease. In addition, the fungicides of chlorothalonil and mancozeb could also be chosen. The resistance to thiophanate-methyl, kresoxim-methyl and diniconazole was appeared in the tested pathogens. In cross-resistance test, the results showed that carbendazim, kresoxim-methyl and diniconazole had cross-resistance each other, while kresoxim-methyl and validamycin A had negative cross-resistance each other. To avoid the resistance of the pathogen to the fungicides, such fungicides should be used by turns.