ABSTRACT
Distributon and epidemiological factors in relation to Barley YeIIow Dwarf Virus in Chile

Guido Herrera M.1 Carlos Quiroz E.1
 

The distribution of BYDV and some epidemiological factors were studied, based on the collection of samples from affected fields and the counting of vector populations on experimental plots and on commerciai wheat fields. It was concluded that BYDV is present from Vallenar to Valdivia, with a higher frequency of PAV strains in the northern zone and of the mixture of the PAV and MAV strains, in the southern zone of Chile. The counting of vector populations, from 1976 to 1980, indioated that the aphids in the Íast three years have decreased their population. Besides, variations have been observed in relation with the time of arrival to the fields and the relative abundance of the different vector species. The virus was transmitted by Rhopalosiphum padi, Sitobion avenae, Metopolophium dirhodum, and Schizaphis graminum.

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1 Estación Experimental La Platina (INIA), Casilla 5427, Santiago, Chile.