Maize dwarf mosaic virus in Idaho.
Maize dwarf mosaic virus was identified in sweet maize in Idaho in 1977; this is the first report of the disease in the Pacific Northwest of the USA. Massive flights of aphids consisting mainly of the vector Schizaphis graminum (Rond.) contributed to the incidence of the disease, and yield reductions of 75% or more were recorded in severely affected fields. Plants in late-seeded fields were the most susceptible.<new para>ADDITIONAL ABSTRACT:<new para>The 1st report of maize dwarf mosaic virus in the Pacific northwest was on sweet corn in Idaho in 1977. Yield reductions of > 75% were recorded in severely affected fields and susceptibility was associated with late sowing. No further outbreaks were reported during the period 1977-9.