Chemical and physical disinfection of peanut pods for improved seed quality

Peanut pod wart is a new disease in Israel that causes ugly warts on the pod. The causal agent, Streptomyces sp., contaminates seed during mechanical cracking of pods. Low-volume application of 3% iodine dissolved in glacial acetic acid resulted in effective pod disinfection and reduced the surface pods microflora by 4 log orders, but this mixture causes eye irritation and has an unpleasant smell. A 4 s exposure of the pods to a butane-air flame at 740 °C eradicated the pathogen and even a 6 s exposure did not affect seed germination or yield. This physical treatment also reduced significantly the incidence of other seedborne fungi, e.g. Aspergillus niger and Rhizopus stolonifer, in the laboratory and in a large-scale field test. Flaming enables the treatment of large quantities of pods prior to cracking.