Influence of Seeding Rate and Interplanting with Tall Fescue on Virus Infection of White Clover. G. E. Brink, Research Agronomist, USDA-ARS-CSRL, Forage Research Unit, Mississippi State, MS 39762. M. R. McLaughlin, Research Plant Pathologist, USDA-ARS-CSRL, Forage Research Unit, Mississippi State, MS 39762. Plant Dis. 74:51-53. Accepted for publication 27 July 1989. 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, 1990. DOI: 10.1094/PD-74-0051.

The effects of white clover seeding rate and tall fescue seeding method on virus infection of white clover were determined in field plots during 1986 and 1987. Incidence of peanut stunt virus (PSV) in the cultivar Regal in July and November 1986 was greater where clover had been sown at 0.56 kg/ha than where it had been sown at 1.68 or 3.36 kg/ha. Clover yield measured after virus sampling of plots sown at the two higher rates was similar and was greater than that of plots sown at the lowest rate. Although clover yield in July 1987 was similar across clover seeding rates, incidence of PSV decreased as seeding rates increased. Incidence of white clover mosaic virus (WCMV) was lower and that of alfalfa mosaic virus (AMV) was higher in 1987 at successively greater seeding rates. The method of seeding tall fescue (broadcast vs. drilled) did not influence the incidence of virus infection. Reduced incidence of WCMV and AMV infection of white clover sown with tall fescue compared with monoculture was a benefit of this forage combination.