Author : Chan Han Hee

Summary : Kelman's, Karganilla and Buddenhagen's, Nesmith and Jenkins', and Harris' media were studied for their selectivity and efficiency in recovering P. solanacearum from soils. results indicated that Nesmith and Jenkins' medium was the most suited to use for quantitative assay of the pathogen in some Philippine soils. On this medium, P. solanacearum produced very fluidal, 2-3 mm diameter, round colonies with bright red diffused formazon centers and narrow white margins within 60 to 72 hours incubation at 30 deg C; recovery of the pathogen from pure culture suspensions was comparable to those on non- selective casein-glucose-peptone and tetrazolium chloride (TZC) media. Lower recovery and significant suppression of growth was observed on the other test media.