VIEW ARTICLE

Techniques

A Wound-Freezing Inoculation Technique for Evaluating Resistance to Cytospora leucostoma in Young Peach Trees. Ralph Scorza, Research horticulturist, U.S. Department of Agriculture, Agricultural Research Service, Appalachian Fruit Research Station, Kearneysville, WV 25430; P. Lawrence Pusey, postdoctoral plant pathologist, West Virginia University, Kearneysville 25430, Present address: Research plant pathologist, U.S. Department of Agriculture, Agricultural Research Service, Southeastern Fruit and Tree Nut Research Laboratory, Byron, GA 31008. Phytopathology 74:569-572. Accepted for publication 31 January 1984. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1984. DOI: 10.1094/Phyto-74-569.

A reliable method of inoculating young peach (Prunus persica) trees (0.95- 1.6 cm in diameter) with Cytospora leucostoma is reported. Trees were wounded to xylem depth with an empty handheld stapling gun. The wound area was frozen with a commercial aerosol tissue-freezing product and inoculated with a suspension containing 10⁷ pycniospores of C. leucostoma per milliliter. Cultivar susceptibility was rated by measuring the area and extension of xylem necrosis. The selection of the least susceptible and most susceptible cultivars as determined by these ratings was consistent for trials conducted for 3 yr, and agreed with previously reported field ratings. Although significant differences in susceptibility to C. leucostoma were found, the resistance reaction was weak. Significant year and year × cultivar effects indicated that nongenetic influences were a major component of variability.