Maize dwarf mosaic virus
Area of impact: Leaves and ears
Description: Begins as pale spots and streaks that later develop into a mottled or mosaic pattern. Growth may be stunted, upper internodes may be shortened, ear formation may slow and excessive tillering may be present.
Pathogen involved: Virus
Timing/Conditions: Transmitted by aphids or by leaf rubbing. Symptoms occur six weeks after the virus is transmitted. Prefers average to warm temperatures.
Contributing factors: Nearby infected johnsongrass.
Management practices: Select tolerant commercial hybrids, avoid aphids and control johnsongrass with herbicides.