VIEW ARTICLE

Quantitative Assessment of Verticillium albo-atrum in Field Soils: Procedural and Substrate Improvements. O. C. Huisman , Assistant Professor, Department of Plant Pathology, University of California, Berkeley 94720; L. J. Ashworth, Jr., Plant Pathologist, Department of Plant Pathology, University of California, Berkeley 94720. Phytopathology 64:1043-1044. DOI: 10.1094/Phyto-64-1043.

Improvements in a wet-sieving procedure for concentrating microsclerotia of Verticillium albo-atrum in residues of field soils, preparatory to culturing, increased assays from 18-24 to 36-40 per operator per day. Pectate (sodium polygalacturonate) was equal to cellophane as a principal carbon source. Advantages of a pectate substrate over sugarless Czapek’s agar, overlaid with cellophane, are (i) ease of preparation, (ii) ease of removal of soil residues following incubation, and (iii) extended incubation periods are possible, thus offering the potential of visual counting of Verticillium colonies.