The study was carried out in a greenhouse at Plant Pathology Research Institute, “Agricultural Research Center, Giza, Egypt" to evaluate bio-char applications of  potato scab controlling  caused by Streptomyces scabies in sandy and clayey textured soil. Water dressing of potting soils was discussed with the influence of bio-char application to both kinds of infested and non-infested soils. The results showed that the application of bio-char for potato seed bed and the regular irrigation (every 3 days) caused an increase in organic carbon in both sterilized soils. While, the bio-char application in state under seedbed for infested sandy soil caused low nitrogen content at both watering treatments. In this preliminary study similar results were shown in clayey infested soil. Which soil porosity that is being inversely related to disease and it is positively correlated to soil bulk density (bd). Also, the results showed that bio-char application decreased the interspaces between particles consequentially minimizing soil bulk density for watering treatments in concern. The soil reaction (pH) was increased with the application of bio-char to infested soil under both watering system. Bio-char amended sandy and clayey soils expressed decreased incidence of scabby tubers especially at higher dose regular watering. This preliminary study reveals that the necessity of bio-char field treatments, to explain in depth the physiological, histological and changes in soil edaphic factors as related to Streptomyces scabies infections.