Potato (Solanum tuberosum L.) is considered one of the main food crops in many countries worldwide. The present work was planned to manage potato black-leg disease using organic treatments as well as mineral-nitrogenous treatments, in addition to examining their effects on the pathogenic bacterium (Pectobacterium atrosepticum) population under artificial inoculation conditions. The obtained data indicated that applications of cabbage, onion and peppermint dry ground leaves as organic matters, and applications of ammonium super-phosphate, potassium sulfate and urea as mineral-nitrogenous fertilizers reduced P. atrosepticum population and black-leg disease of potato compared with the control treatment. In addition, these treatments led to increasing potato yield, while the beneficial effects increased with increasing their doses compared with the control treatment. Meanwhile, the organic matter appeared highly effective compared with mineral-nitrogenous fertilizers in disease reduction. However, mineral-nitrogenous fertilizers appeared highly effective in increasing potato yield. Meanwhile, onion dry ground leaves (organic matter) and urea (nitrogenous fertilizer) were the most effective on the pathogenic bacterium population and severity of the disease compared with other treatments