Efficacy of several ethanolic plant extracts against infection of cucumberplants by Sphaerotheca fuliginea (Schlecht. ex Fr.) Poll.; disease controlby Cassia extracts

摘要

Ethanolic extracts of 69 native and introduced plane species in Greece were applied on the first leaf of young cucumber plants, 2-3 days before artificial inoculation with a conidia suspension of Sphaerotheca fuliginea, in order to test their efficacy against powdery mildew of cucumbers. Extracts of Cassia septentrionalis and C. x floribunda flowers and pods at the concentration of 2.5 % (w/v) highly reduced the percentage leaf coverage by the pathogen. The EC50 and EC95 values of all Cassia pod and flower extracts were determined. In additional trials, it was shown that all Cassia extracts were more effective against the pathogen by preventive application. The obtained data clearly show the antifungal properties of C. septentrionalis and C, x floribunda flower and pod extracts in the cucumber-S. fuliginea pathosystem.