Maize Dwarf Mosaic Virus


  • Symptoms often begin as chlorotic spots and streaks on green, young leaves, which later develop into a mottle or a mosaic pattern
  • Viral strain, corn genotype, and stage of corn development at the time of infection will affect the type of symptoms
  • Upper internodes of corn may be shortened, and excessive tillering may occur
  • Ear formation and development may slow, which may cause grain yield loss
  • Hybrids infected early in their growth stage may be stunted

Pathogen Involved:

  • Maize dwarf mosaic (a potyvirus)
  • This pathogen consists of 4 strains: C, D, E, and F
  • Aphids (= 15 species) can transmit MDMV non-persistently
  • Can be seed transmitted at a low frequency or mechanically transmitted by leaf rubbing, etc.
  • Infects Johnson grass and sorghum

Time of Occurrence:

  • Symptoms appear six weeks after aphids feed and transmit this virus

Conditions Favoring Disease:

  • Average to warm temperatures
  • Nearby Johnson grass infected with MDMV may increase disease

Disease Management:

  • Use tolerant commercial corn hybrids
  • Avoidance of aphid vectors
  • Control of Johnson grass with herbicides may be beneficial