How to Identify and Treat Maize Diseases: Symptoms, Spread, and Control Management

Welcome to our blog on common maize diseases and their management! Maize, or corn, is a major crop worldwide but is susceptible to various damaging diseases. Maize (Zea mays L. ssp. mays) is a grain domesticated by indigenous peoples in Mesoamerica. It is grown in various environments in India and worldwide as a vegetable and starch. Maize cultivation in India can be divided into traditional and non-traditional areas, catering to commercial purposes, particularly for the poultry industry.

How to Identify and Treat Maize Diseases

Understanding the causes, symptoms, spread, and effective control methods is crucial for successful maize cultivation. This article will provide concise and accessible information about these diseases, capturing your attention while delivering valuable insights. Let’s delve into maize disease management and safeguard your crop’s health and yield.

Major Common Damaging Disease of Maize/ Corn Crop

  1. Gray Leaf Spot (GLS): Grayish-green lesions with dark borders appear on maize leaves, reducing photosynthetic efficiency and affecting yield.
  2. Northern Leaf Blight (NLB): Elongated, cigar-shaped lesions with gray-green or tan centers develop on leaves, reducing plant vigor and yield loss.
  3. Southern Rust: Orange to rusty-brown pustules form on leaves, reducing photosynthesis and causing premature leaf senescence.
  4. Common Rust: Small, reddish-brown pustules appear on leaves, affecting plant health and grain quality.
  5. Diplodia Ear Rot: Whitish mold covers maize kernels, reducing grain quality and causing mycotoxin contamination.
  6. Fusarium Ear Rot: Pink or white fungal growth develops on maize ears, reducing kernel quality and mycotoxin contamination.
  7. Stalk Rot: Maize stalks become weak and may collapse due to fungal infections, resulting in lodging and yield loss.
  8. Goss’s Wilt: Dark-green to black “freckles” or “water-soaked” lesions with a bacterial ooze appear on leaves, reducing photosynthesis and yield.
  9. Maize Dwarf Mosaic Virus (MDMV): Stunted growth, mosaic patterns, and yellowing of leaves occur due to viral infection, leading to reduced yield.
  10. Maize Streak Virus (MSV): Infected plants show yellow streaks or mottling on leaves, reducing photosynthetic efficiency and overall yield.

How to Identify and Treat Maize Diseases

Maize Rust

  • Causes: Caused by the fungus Puccinia polysora.
  • Symptoms: Circular golden-yellow to brown raised structures (pustules) on leaves.
  • Spread: Favored by high temperatures (around 27°C) and humidity.
  • Control: The use of resistant varieties is the most feasible measure.

Maize Leaf Blights

  • Causes: Caused by the fungus Helminthosporium maydis.
  • Symptoms: Appearance of spots (lesions) on leaves, progressing upward.
  • Control: Fungicidal sprays like Zineb, Maneb, and Cuman can be used, but planting resistant varieties is the most effective method.

Curvularia Leaf Spot

  • Causes: Caused by the fungus Curvularia pallescens.
  • Symptoms: Small circular spots with grey centers and brown borders.
  • Control: Spraying with fungicides like Miltox and Copranol is possible but less economical. Planting-resistant varieties are recommended.

Brown Spot

  • Causes: Caused by the fungus Physoderma maydis.
  • Symptoms: Tiny yellowish spots on leaves turning brown.
  • Control: Well-planned crop rotation and use of resistant varieties.

Downy Mildew

  • Causes: Caused by the fungus Peronosderospora sorghii.
  • Symptoms: Chlorosis, stunted growth, deformed tassel, and ear.
  • Control: Plant resistant varieties, seed dressing with appropriate chemicals, rogue and destroy infected plants, and avoid late planting.

Maize Streak Virus (MSV)

  • Causes: Spread by leafhoppers belonging to the genus Cicadulina.
  • Symptoms: Chlorotic streaks along veins, stunted growth, poor cobs.
  • Control: Use streaks-resistant varieties, crop rotation, and avoid late planting.

Note: Proper disease control measures include using resistant varieties, timely fungicidal sprays, seed dressing, crop rotation, and eliminating infected plants. By implementing these preventive strategies, farmers can effectively manage and protect their maize crops from the damaging effects of these diseases.