Relationships of Virus Infections to Field Performance of Six Clover Species. R. Alconero, Northeast Regional Plant Introduction Station, Geneva, NY 14456. B. Fiori, and W. Sherring, Northeast Regional Plant Introduction Station, Geneva, NY 14456. Plant Dis. 70:119-121. Accepted for publication 28 June 1985. This article is in the public domain and not copyrightable. It may be freely reprinted with customasource. The American Phytopathological Society, 1986. DOI: 10.1094/PD-70-119.

Eighty-one Trifolium ambiguum accessions, representing the germ plasm collection for that species, and selected accessions of T. alpestre, T. hybridum, T. medium, T. pratense, and T. repens were evaluated in the field from 1981 through 1983 for overall vigor, persistence, yield, and susceptibility to virus infections. Infections by bean yellow mosaic virus, clover yellow vein virus, white clover mosaic virus, and red clover vein mosaic virus were common in many accessions. Accessions of T. ambiguum and T. medium were the least affected by virus infections and persisted better than other species. Symptoms of virus infection appeared early and spread rapidly in accessions of T. hybridum, T. pratense, and T. repens and were associated with loss of vigor and death of most of the plants by 1983. T. alpestre accessions were only moderately affected by viruses but showed neither the rapid growth of T. hybridum, T. pratense, or T. repens nor the persistence of T. ambiguum or T. medium. Several accessions of T. ambiguum compared favorably with developed cultivars of T. pratense after 2 yr of field exposure.