Disease Note.

Barley Yellow Dwarf Viruses Infecting Oats and Wheat in Louisiana. R. A. Valverde, Department of Plant Pathology and Crop Physiology, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge 70803. S. A. Harrison, Department of Agronomy, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge 70803. Plant Dis. 73:938. Accepted for publication 28 July 1989. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/PD-73-0938E.

During the spring of 1988, leaf samples of oats (Avena sativa L. 'Citation' and 'Coker 227') and wheat (Triticum aestivum L. 'McNair 1003' and 'Terral 817') showing reddening and yellowing symptoms, respectively, were collected from six commercial fields in south and central Louisiana. Because the causal agent was suspected to be barley yellow dwarf virus (BYDV), samples were tested by enzyme-linked immunosorbent assay, using polyclonal antisera (from J. Duffus) to three New York BYDV serotypes-PAV, MAV, and RPV. Of 50 wheat samples tested, 35 were infected with PAY, 4 with RPV, and II with both. Of 30 oats samples tested, 12 were infected with P A V, 15 with RPV, and 3 with both. Three PAY and two RPV isolates were transmitted from infected oats to healthy 'California Red' oats by Sitobion avenae F. and Rhopalosiphum padi L., respectively. This is the first report of these two BYDV serotypes in Louisiana.