Identification and Importance of Barley Yellow Dwarf Virus in Morocco. M. El Yamani, National Institute for Agronomic Research, Settat, B.P. 290, Morocco. J. H. Hill, Department of Plant Pathology, Iowa State University, Ames 50011-1020. Plant Dis. 74:291-294. Accepted for publication 16 October 1989. Copyright 1990 The American Phytopathological Society. DOI: 10.1094/PD-74-0291.

Rhopalosiphum padi-specific, R. maidis-specific, and nonspecific strains of barley yellow dwarf virus (BYDV) were identified in Morocco during 1980–1982. Five species of aphids were identified as vectors of the virus. Inoculation of 12 grass species endemic to the area showed that two were immune and 10 were susceptible, of which three were symptomless. Early inoculation (stages 1 and 2 on Feekes scale) of bread wheat cultivar Nesma 149 with BYDV induced 43% yield loss, whereas later inoculation (stages 5 and 6) caused 29% loss.