Corn stunting virus diseases in Missouri (1979)

First reports of stunting virus diseases of corn were made in Missouri in 1963 from three southeastern counties. Similar reports were made from neighboring states. Virus or virus-like diseases of corn have been reported annually since the time of the first appearance in epidemic proportions in the southern part of the Corn Belt. Infections occur in more than 7,000 acres annually in Missouri. Since 1963, losses ranging from 5 to 95 per cent in individual fields have been reported in Missouri. The most severe losses have occurred in bottom land fields along the Gasconade and Missouri rivers. Most of these areas have fields that are surrounded or infested by Johnsongrass, a common perennial weed grass proven to be a principal over-wintering host for two corn viruses, maize dwarf mosaic virus and maize chlorotic dwarf virus.Reprinted 9/79/8M