Rhizoctonia solani Kühn aislado de papa (Solanum tuberosum L.): En los estados Táchira, Mérida, Trujillo y Lara. I. Caracterización cultural

potato is one of the most important crops in venezuelan economy. this crop is affected by different pathogens, one of which is the fungus rhizoctonia solani, the inducer of rhizoctonia disease; which is widely distributed and is the cause of considerable economic losses. in order to know phenotypic variation among fungus populations, this research was carried out with samples collected at different potato producing areas of táchira, merida, trujillo, and lara states. the pathogen was culturally characterized by the study and determination of its nuclear condition, anastomosis group (ag), as well as colony growth, and number and diameter of sclerotia at 10, 20 and 30 °c. significant differences (p≤0.01) were found among strains with regard to the cultural characteristics; in general, strains showed better behavior of their development at 20 °c; 97.5 % of the strains were found to be ag-3 and the other 2.5 %, ag-2.1. results indicated differences in cultural characteristics among the r. solani populations, which may be associated with disease behavior at the different localities.