Control of a Molding-Root Rot Complex of Black Walnut Seedlings in Storage. R. J. Green, Jr., Professor of Plant Pathology, Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907. Plant Dis. 69:398-400. Accepted for publication 10 December 1984. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/PD-69-398.

Losses as high as 30% of black walnut seedlings in winter storage in Indiana nurseries are caused by a molding-root rot complex. Several fungi are involved in the molding phase. Species of Fusarium and Pythium are associated with the root rot, which is distinct from that caused in the seedbed by Phytophthora citricola. Losses in cold storage were significantly reduced by packing seedlings in plastic-lined bags rather than by moist packing. A fungicide (captafol) root dip before storage reduced losses further. Seedlings outplanted after these treatments displayed 98–100% survival and generally better growth than controls. Seedlings that had molded or sustained decay of as much as 25% of the taproot survived at rates of 70–88%.