Oxalic acid production by Sclerotinia homoeocarpaFungi in the genus Sclerotinia include some of the most devastating pathogens known. Dollar spot, caused by S. homoeocarpa, is the most prevalent and sprayed for disease of golf course turf. The production of oxalic acid and pectolytic cell wall-degrading enzymes by species within this genus is well documented. A series of laboratory-based assays were used to determine whether S. homoeocarpa produces oxalic acid. Potato dextrose agar (PDA) adjusted to pH 4 and pH 6, with and without bromophenol blue (Bb), was used to assess the growth of and acid production by S. homoeocarpa between 5-35 C. When added to PDA, Bb only slightly hindered the growth of S. homoeocarpa. Acid production by S. homoeocarpa on PDA + Bb occurred between 15-30 C at both pHs, but was first observed on media adjusted to pH 6. Maximum acid production occurred between 20-30 C. Acid production by S. homoeocarpa was also observed when grown in potato dextrose broth (PDB) at 25 C. High Performance Liquid Chromatography analysis of spent culture broth collected from S. homoeocarpa inoculated PDB revealed the presence of oxalic acid.Department of Plant Pathology, The Ohio State Universit
