VIEW ARTICLE

Disease Control and Pest Management

Biological Control to Reduce Inoculum of the Tan Spot Pathogen Pyrenophora tritici-repentis in Surface-borne Residues of Wheat Fields. William F. Pfender,Department of Plant Pathology, Throckmorton Hall, Kansas State University, Manhattan 66506-5502; Wei Zhang, and Ann Nus. Department of Plant Pathology, Throckmorton Hall, Kansas State University, Manhattan 66506-5502. Phytopathology 83:371-375. Accepted for publication 28 December 1992. Copyright 1993 The American Phytopathological Society. DOI: 10.1094/Phyto-83-371.

Field plots of conservation-tillage wheat straw naturally infested with Pyrenophora tritici-repentis were treated with bran-based inoculum of three potential biocontrol fungi, and reduction in the number of residue-borne pseudothecia (primary inoculum of the pathogen) was determined. Limonomyces roseipellis significantly reduced residue-borne primary inoculum of P. tritici-repentis in 3 of 4 yr of experiments; an unidentified agonomycete was effective in two of three experiments, but Laetisaria arvalis was ineffective. Although L. roseipellis reduced inoculum by 60–80%, greater reductions would be necessary for acceptable control of this disease. Retention of dry bran-based inoculum on straw was enhanced by the use of alginate, but further improvements in formulation and application methods are required for effective biocontrol of pathogens in surface-borne crop residues.