Maize rough dwarf

Maize rough dwarf is a viral plant disease caused by the Maize rough dwarf virus (MRDV), which belongs to the family Reoviridae. The virus is persistent in its vectors, meaning that leafhoppers such as Laodelphax striatellus remain infective throughout their entire life cycle after acquiring the pathogen.

The disease has a significant impact on cereal crops. While maize is the primary host, the virus also affects sorghum and winter wheat. These crops serve as critical reservoirs for the virus, bridging the gaps between growing seasons and allowing the infection to persist in the field environment.

Visible symptoms include severe stunting, dark green discoloration, and the shortening of internodes. The most diagnostic characteristic of the disease is the presence of small, rough-textured enations (galls) on the abaxial side of the leaves and on the leaf sheaths, which disrupt normal plant development and nutrient transport.

Development and spread are largely determined by the migration patterns of the vector population. The highest incidence occurs when early-season planting coincides with the peak flight of leafhoppers. Infection at the early seedling stage causes the most severe damage, frequently leading to total crop failure and the production of deformed, sterile ears.

Management and prevention strategies focus on limiting the vector-host interaction. Key practices include

• Planting resistant or tolerant corn hybrids
• Adjusting sowing dates to avoid peak leafhopper migration
• Controlling weed hosts that harbor the virus
• Applying systemic insecticides to minimize vector populations during the vulnerable early growth stages