Late blight on potato is suppressed by the biosurfactant-producing strain Pseudomonas koreensis 2.74 and its biosurfactant

Potato late blight disease caused by the zoospore-producing pathogen Phytophthora infestans (Mont.) de Bary is one of the most destructive plant diseases world-wide and currently its management mainly relies on the frequent use of fungicides. This study investigated the possibility to reduce potato late blight through biocontrol with the biosurfactant-producing strain Pseudomonas koreensis 2.74. A significant disease reduction with the biosurfactant-producing strain and its biosurfactant was observed in greenhouse trials using a detached leaf assay. A direct effect of the biosurfactant on zoospores of P. infestans was also observed, while the biosurfactant only caused a minor reduction in mycelial growth rate and had no effect on the rate of sporangia production in pure culture