Transmission of Spring Dead Spot Disease of Bermudagrass by Turf/Soil Cores. J. C. Pair, Professor, Department of Horticulture, Kansas State University, Manhattan 66506. F. J. Crowe, Assistant Professor, Extension Plant Pathologist, and W. G. Willis, Professor, Extension Plant Pathologist, Department of Plant Pathology, Kansas State University, Manhattan 66506. Plant Dis. 70:877-878. Accepted for publication 24 February 1986. 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, 1986. DOI: 10.1094/PD-70-877.

Transmission of spring dead spot disease of bermudagrass (Cynodon dactylon) was accomplished with turf / soil cores taken in 1973. Cores from edges of dead turf patches in a bermudagrass lawn were transplanted into 24 established bermudagrass clones in an area where the disease had never been observed. Two to 4 yr were required for symptom expression. Once symptoms appeared at a given transplant location, spring dead spot tended to recur in the same location in successive seasons, increasing in size in subsequent years. After 1977, no new sites developed the disease, but by 1982, the number of sites diminished because spring dead spot failed to recur at some sites and other sites converged as they enlarged. Symptoms appeared at 6.7, 19.9, 36.0, 35.6, and 25.5% of the 192 inoculation sites in 1975, 1976, 1977, 1978, and 1982, respectively. No disease occurred either at sites into which symptomless cores were transplanted or at otherwise random locations in or near the test plots. In addition to demonstrating transmissibility, this technique appears promising to screen bermudagrass clones for resistance to spring dead spot.

Keyword(s): resistance screening.