This study was conducted to determine the inhibitory effect of E-cinnamaldehyde (EC) against causal agent of
storage carrot rot, Sclerotinia sclerotiorum, under in vivo and in vitro conditions. Based on the results, EC was
able to completely inhibit mycelial growth of three isolates (P N 0.05) in both volatile and contact phases after
6 days at the concentrations 200 μl and 1 μl/ml, respectively. In addition, EC at concentrations 1 and 10 μl/ml
completely inhibited carpogenic germination of three isolates. The results of in vivo trials showed that EC at
the concentration of 10 μl/ml was able to control the disease caused by isolates 1 and 3. However the disease
caused by isolate 2 was inhibited with the concentration of 20 μl/ml. In enzyme analyses, the activity of
polyphenoloxidase and peroxidase did not change in the inoculated carrots after application of EC. Furthermore,
the level of phenylalanine ammonia lyase decreased. These results indicated that EC does not have any potential
to be considered as resistance inducers against sclerotinia carrot rot.