Incredible. Maize Dwarf Mosaic (virus): Maize Dwarf Mosaic virus is the most common virus disease of sweet corn in Texas. Infected plants have mottled upper leaves that are lighter in color than healthy leaves. The mottled or mosaic pattern consists of alternate yellow and green islands in the leaf tissue.aize Dwarf Mosaic (virus): Maize Dwarf Mosaic virus is the most common virus disease of sweet corn in Texas. Infected plants have mottled upper leaves that are lighter in color than healthy leaves.