Effect of Cachaza (Filter Press Cake) and Sodium Chloride on Infection of Sugarcane by Thielaviopsis paradoxa in Puerto Rico

Abstract

The optimum filter press cake extract mixture content for mycelial growth of the various isolates of Thielaviopsis paradoxa from sugarcane and pineapple was found to be 19 percent. Pathogenicity of T. paradoxa to sugarcane variety P.R. 980 was favored by high proportions of filter press cake. The rate of infection of sugarcane by this fungus increased with an increase of the percentage of filter press cake. The optimum concentration of sodium chloride for mycelial growth in a water agar medium was between 0.3 and 0.6 percent. The rate of infection of sugarcane seedpieces by T. paradoxa (dark strain) was lower with a higher sodium chloride content of the sand when inoculated at temperatures of 22° to 25° C.