Objective The aim was to explore the role of coumarin and cinnamic acid in the occurrence of cucumber wilt.

Method The Fusarium oxysporum f. sp cucumerinum (FOC) and Jinyan No. 4 cucumber varieties were used as test materials to find out the treatment of exogenous coumarin and cinnamic acid. The growth, reproduction, pathogenicity and cucumbers of FOC were mainly changes in anti-disease physiological indicators and the degree of occurrence of blight.

Results The results showed that exogenous coumarin significantly inhibited the growth, reproduction and pathogenicity of FOC, and improved the activity of cucumber chitinase and β-1,3-glucanase, increased the content of flavonoids and lignin in the cucumber root system, and reduced the incidence of cucumber wilt. Exogenous cinnamic acid significantly promoted the growth, reproduction and pathogenicity of FOC, inhibited the activities of cucumber chitinase and β-1,3-glucanase, reduced the contents of flavonoids and lignin in the cucumber root system, and aggravated the incidence of cucumber blight.

Conclusion By reducing the pathogenic factors related to the bacteria and enhancing the disease-related factors of cucumbers, exogenous coumarin improves the resistance of cucumbers to wilt and reduces the occurrence of wilt. However, cinnamic acid is the opposite.