Maize mosaic

Causative agent and type of disease. The causative agent is the virus Gammanucleorhabdovirus maydis, a member of the Rhabdoviridae family. It is a systemic viral disease that disrupts the physiological functions and vascular transport within the corn plant, leading to significant physiological stress.

Affected crops. The virus primarily infects maize (Zea mays). While it is most economically significant in field corn, it can also infect sweet corn and various other cultivars, making it a widespread concern for farmers globally.

Symptoms and signs of infection. Typical symptoms include mosaic patterns, streaks, or chlorotic mottling on the leaves. Infected plants often exhibit stunted growth, reduced leaf area, and poor ear development. The quality of the grain is often compromised, with smaller or improperly filled cobs leading to reduced market value.

Conditions for development and spread. The virus is transmitted by insect vectors, primarily leafhoppers. The spread of the disease is highly correlated with the activity and density of these vectors. Warm temperatures and high humidity promote both the reproduction of the insect vectors and the successful transmission of the virus to young, susceptible plants.

Harmfulness and protection measures. The disease can cause severe crop yield losses, especially when infection occurs at an early vegetative stage. Effective management strategies include:

• Utilizing genetically resistant or tolerant corn hybrids.
• Implementing insecticide programs to control leafhopper populations.
• Sanitation practices, including the removal of weeds and volunteer corn that act as virus reservoirs.
• Adopting proper crop rotation practices to break the disease cycle.