Studies On The Transmission Of Potato Brown Rot Causal Organism Through Weeds In The Egyptian Fields

Five Potato Cultivars, Grown In Soil And Inoculated By 12 Isolates Of R. Solanacerum, Showed Various Levels Of Disease Resistance. Sponta And Pyrnadets Cvs. Were More Sensitive: Nicola Cv. Was Moderate Sensitive: Mondial Cv. Was Moderate Resistant, While Lady Roasita Was Resistant To The Pathogen.The effect of previous crop in agricultural rotation, as well as pH value and type of soil structure on persistence of the causal agent was studied. Results indicated that Potato – Rice crop rotation was more effective in decline the population density of R. solanacearum rather than Potato – Maize and Potato – Peanut. The persistence of the causal agent could be declined with higher or lower pH value rather than 7.2 to 7.7 pH.