Monitoring for the Resistance to Prochloraz of Fusarium Species Causing Bakanae Disease in Korea

To investigate the changes of the resistance to prochloraz of Fusarium species causing bakanae disease, Fusarium isolates were collected from various regions in Korea, and pathogenicity tests were performed using rice seeds. Minimum inhibitory concentration (MIC) and effective concentration of 50% () values of isolates were determined using the agar dilution method. High frequency distribution of MIC values of prochloraz against isolates collected in 2006~2007 and 2013~2014 years were and , respectively. The mean value of isolates increased from in 2006~2007 to in 2013~2014. Based on the value of isolates collected in 2006~2007, the resistant baseline of prochloraz was determined as . Compared with the ratio of resistant isolates in 2006~2007, the ratio of resistant isolates in 2013~2014 increased from 6.5% to 41.6%.