Pests and Diseases of Maize (Zea mays L.) and Their Management

Pests and Diseases of Maize (Zea mays L.) and Their Management

Introduction

Maize (Zea mays L.), also known as corn, is one of the most important cereal crops in India. It is widely grown for food, fodder, poultry feed, and industrial purposes such as starch, ethanol, and corn oil. India cultivates maize on more than 10 million hectares, with major producing states including Karnataka, Madhya Pradesh, Maharashtra, Telangana, Andhra Pradesh, Bihar, Uttar Pradesh, and Rajasthan.

Despite its high yield potential, maize productivity is often affected by insect pests and diseases, which can cause 20–40% yield loss, and in severe cases even complete crop failure. Climate change, continuous monocropping, and improper pesticide use have further increased pest and disease pressure, especially in recent years.

To achieve healthy crop growth and sustainable maize production, farmers must understand:

  • Common pests and diseases of maize
  • Their symptoms and damage
  • Favorable conditions
  • Integrated management practices

This blog provides a comprehensive, field-oriented guide on major pests and diseases of maize and their management, useful for farmers, agri-input dealers, agronomists, and agriculture students.

Major Insect Pests of Maize and Their Management

1. Fall Armyworm (Spodoptera frugiperda)

Identification & Symptoms

  • Larvae are greenish-brown with an inverted “Y” mark on the head
  • Irregular holes on leaves
  • Whorl feeding with sawdust-like frass
  • Severe attack leads to complete defoliation

Nature of Damage

  • Feeds on leaves, whorl, tassel, and cobs
  • Most destructive during early crop stages

Favorable Conditions

  • Warm and humid climate
  • Continuous maize cultivation

Integrated Pest Management (IPM)

  • Cultural: Early sowing, avoid staggered planting
  • Mechanical: Hand-picking larvae, destroy egg masses
  • Biological: Release Trichogramma spp., apply Bacillus thuringiensis
  • Chemical: Spray recommended insecticides only when ETL is crossed

2. Stem Borer (Chilo partellus)

Symptoms

  • Pin holes on leaves
  • Dead heart formation in young plants
  • Tunneling inside stem

Damage

  • Reduces nutrient flow, stunts plant growth
  • Affects cob formation

Favorable Conditions

  • High temperature and humidity
  • Late sowing

Management

  • Cultural: Remove stubbles, timely sowing
  • Biological: Release Trichogramma chilonis
  • Chemical: Need-based application of insecticides

3. Shoot Fly (Atherigona spp.)

Symptoms

  • Central leaf drying (dead heart)
  • Seedling wilting

Damage

  • Affects crop during early stages (1–4 weeks)

Management

  • Seed treatment with recommended insecticides
  • Early sowing
  • Maintain optimum plant population

4. Aphids

Symptoms

  • Curling and yellowing of leaves
  • Sticky honeydew secretion
  • Sooty mold development

Damage

  • Suck sap, reduce plant vigor
  • Transmit viral diseases

Management

  • Encourage natural enemies like ladybird beetles
  • Spray neem-based formulations
  • Chemical control if infestation is severe

5. Cutworms

Symptoms & Damage

  • Cut seedlings at ground level during night
  • Patchy crop damage

Management

  • Deep ploughing before sowing
  • Remove weeds
  • Soil application of recommended insecticides

6. White Grubs

Damage

  • Feed on roots
  • Plants wilt and die suddenly

Management

  • Summer ploughing
  • Use well-decomposed FYM
  • Soil insecticide application if required

Major Diseases of Maize and Their Management

1. Turcicum Leaf Blight (Exserohilum turcicum)

Symptoms

  • Long, cigar-shaped grey lesions on leaves
  • Severe infection causes drying of leaves

Favorable Conditions

  • Cool and humid climate

Management

  • Grow resistant varieties
  • Crop rotation
  • Fungicide spray at early stages

2. Maydis Leaf Blight (Bipolaris maydis)

Symptoms

  • Small rectangular brown lesions
  • Lesions merge and cause leaf drying

Management

  • Use certified seeds
  • Balanced fertilizer application
  • Timely fungicide spray

3. Common Rust (Puccinia sorghi)

Symptoms

  • Reddish-brown pustules on both leaf surfaces
  • Severe infection reduces photosynthesis

Favorable Conditions

  • High humidity and moderate temperature

Management

  • Resistant hybrids
  • Remove volunteer plants
  • Fungicide application if needed

4. Downy Mildew

Symptoms

  • Yellow streaks on leaves
  • White fungal growth on lower leaf surface

Management

  • Seed treatment
  • Rogue infected plants
  • Avoid water stagnation

5. Bacterial Stalk Rot

Symptoms

  • Soft rot of stem base
  • Foul smell
  • Plants lodge easily

Favorable Conditions

  • Waterlogging
  • Excess nitrogen

Management

  • Proper drainage
  • Balanced fertilization
  • Field sanitation

6. Charcoal Rot

Symptoms

  • Premature drying
  • Black discoloration inside stem

Management

  • Avoid moisture stress
  • Crop rotation
  • Use tolerant varieties

7. Fusarium Ear Rot

Symptoms

  • White to pink fungal growth on cobs
  • Shrinking of grains

Impact

  • Reduces grain quality
  • Produces harmful mycotoxins

Management

  • Harvest at proper maturity
  • Avoid insect damage to cobs
  • Proper drying and storage

8. Maize Mosaic Virus

Symptoms

  • Mosaic pattern on leaves
  • Stunted plant growth

Transmission

  • Aphids and leafhoppers

Management

  • Control insect vectors
  • Remove infected plants
  • Use healthy seeds

Integrated Pest and Disease Management (IPDM) in Maize

Integrated Pest and Disease Management is a sustainable approach that combines multiple control methods to reduce dependency on chemicals.

Key IPDM Practices

  • Use certified, disease-free seeds
  • Seed treatment with fungicides and bio-agents
  • Crop rotation with non-host crops
  • Maintain field sanitation
  • Regular crop monitoring
  • Use pesticides only when economic threshold level (ETL) is crossed

Preventive Measures for a Healthy Maize Crop

  • Select suitable hybrids for local conditions
  • Follow recommended spacing
  • Timely sowing and irrigation
  • Balanced application of NPK and micronutrients
  • Use pheromone traps, light traps, and sticky traps
  • Avoid indiscriminate pesticide use

Conclusion

Pests and diseases are major constraints in maize cultivation, but timely identification and integrated management can significantly reduce losses. Farmers should focus on preventive measures, biological control, and need-based chemical application rather than relying solely on pesticides.

Adopting Integrated Pest and Disease Management (IPDM) not only improves yield and quality but also ensures environmentally sustainable maize production. For best results, farmers are advised to consult agriculture experts or extension officers before applying any plant protection chemicals.

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