Optimization of fermentation conditions of Alternaria kikuchiana against the growth of Phytophthora infestans

In order to enhance the inhibitory effect of substances in fermentation liquid of Alternaria kikuchiana 102 strain against the growth of Phytophthora infestans Z182 strain,fermentation conditions of A.kikuchiana were investigated in this experiment by rubbing method or folter paper method in stationary culture status.The results show that the fermentation liquid at temperature 28℃,the natural pH,broth content 80 mL/250 mL,inoculation amount 6% and darkness for culture 8 d have the strongest inhibitory effect on P.infestans.And the inhibitory rate reaches 85.7%,an increase by 15% in comparison with the pre-optimized condition,indicating that there is a great potential for using fermentation substances to control potato late blight.