Effect of acetylsalicylic acid on soft rot produced by Erwinia carotovora subsp carotovora in potato tubers under greenhouse conditions

The efficiency of acetylsalicylic acid (ASA) in inducing localised acquired resistance against infection by Erwinia carotovora subsp. carotovora was evaluated by treating potato tubers with ASA at three concentrations. Three days after treatments, tubers were inoculated with E. carotovora subsp, carotovora by wound inoculation or by irrigation with a bacterial suspension. Experiments were performed for two consecutive years. Statistical analysis revealed that treatment of tubers by immersion in ASA solutions at low concentrations induced a significant reduction in the soft rot incidence. Wounding of the tubers was the most effective inoculation method and ASA at concentration of 0.0125% (w/v), pH 7 was more efficient than at 0.025 or 0.05%. No phytotoxicity of such treatment was observed.