VIEW ARTICLE

Disease Control and Pest Management

Growth of Penicillium oxalicum as a Biological Seed Treatment on Pea Seed in Soil. Carol E. Windels, Scientist, Department of Plant Pathology, University of Minnesota, St. Paul 55108; Phytopathology 71:929-933. Accepted for publication 14 January 1981. Copyright 1981 The American Phytopathological Society. DOI: 10.1094/Phyto-71-929.

When Penicillium oxalicum-treated seeds of Pisum sativum ‘Little Marvel’ were planted in either field or autoclaved soil, the conidia germinated, a hyphal network formed, and the antagonist sporulated on the seed coat by the third day after planting. Small dark lesions and some discoloration of cotyledons were noted after removal of seed coats from P. oxalicum-treated seeds planted in autoclaved soil, but lesions were superficial. Conidia of P. oxalicum were observed, either singly or in groups, on tap and secondary roots and root hairs of plants from P. oxalicum-treated seeds planted in either field or autoclaved soil. In field soil no germinated conidia of P. oxalicum were seen on roots, but in autoclaved soil, conidia germinated and hyphae of P. oxalicum grew between root hairs and on the root surface. Thus, conidia of P. oxalicum applied to seeds appeared to be active and the resulting mycelial network apparently functioned as a seed protectant, but conidia on root surfaces in field soil were apparently dormant.