Occurrence of Barley Yellow Dwarf Viruses in Small-Grain Cereals and in Alternative Hosts in Spain. Enrique Moriones, Departmento de Protección Vegetal, INIA, Carretera de La Coruña, Km 7.5, Apartado 8111, 28040 Madrid, Spain, and Fernando García-Arenal, Departmento de Patología Vegetal, ETSI Agrónomos, Ciudad Universitaria, 28040 Madrid, Spain. Plant Dis. 75:930-934. Accepted for publication 11 March 1991. Copyright 1991 The American Phytopathological Society. DOI: 10.1094/PD-75-0930.
 

The main small-grain cereal producing regions of Spain were surveyed for barley yellow dwarf viruses (BYDV) during the springs of 1987, 1988, and 1989. Barley yellow dwarf was found to be present in all regions of Spain, its incidence varying largely from year to year and among the different geographical regions. Both PAV- and RPV-like isolates were found in all surveyed regions; PAV-like isolates were largely more prevalent than RPV-like ones for cereals but not for weeds or forage grasses. The data on the distribution and relative frequencies of PAV- and RPV-like isolates and the different situations found for cereals and weeds may suggest that inoculum for spring epidemics of these viruses comes from distant sources rather than local reservoirs.