Pests and Diseases of Maize: A Complete Guide for Farmers

Maize (Zea mays), popularly known as corn, is one of India’s most important cereal crops grown across Kharif, Rabi, and Summer seasons. Its high demand in food, feed, starch, and industrial sectors makes it a “farmer’s gold” crop.
However, maize is highly vulnerable to a variety of insect pests and diseases that can significantly reduce crop yield and grain quality. Understanding these pests and diseases along with their symptoms and effective management is essential for profitable maize cultivation.

> MAJOR PESTS OF MAIZE

1.  .Fall Armyworm (FAW) – Spodoptera frugiperda

Fall Armyworm is currently the most dangerous pest in maize, capable of destroying entire fields if not controlled early. Since its arrival in India, it has spread rapidly due to its high reproductive capacity and ability to migrate long distances.

Symptoms of FAW Attack

• Window-pane damage on young leaves caused by early instar larvae.
• Large, irregular holes on leaves at later stages.
• Heavy frass (sawdust-like excreta) deep inside the whorl.
• Plants look "shredded" in severe cases.
• Younger plants show stunting and poor vigour, leading to poor cob formation.

Why FAW Spreads Fast?

• Each female lays 1000–1500 eggs
• Strong flyer (up to 100 km per night)
• Feeds on more than 80 crops
• Hides deep in whorl – not easily affected by normal sprays

Management

Cultural Methods

• Early sowing helps escape peak infestation.
• Deep ploughing to expose pupae.
• Avoid monocropping of maize throughout the year.

Mechanical Methods

• Hand removal of larvae from whorls.
• Use of light traps & pheromone traps @ 4–5/acre.

Biological Control

• Release Trichogramma pretiosum parasitoids.
• Use Bacillus thuringiensis (Bt) formulations for early stages.

Chemical Control

• Emamectin benzoate 5 SG @ 0.4 g/l
• Spinosad 45 SC @ 0.3 ml/l
• Chlorantraniliprole 18.5 SC @ 0.4 ml/l for heavy infestation
• Granules: Fipronil 0.3G in whorl for long-term control

 

 

Maize Stem Borer – Chilo partellus

The Stem Borer is a destructive early-season pest, particularly in Kharif.

Symptoms

• Dead hearts in 2–6 week old plants
• Shot-hole feeding on leaves
• Boreholes in stems and midribs
• Internal tunneling that weakens the plant

Management

• Destroy affected shoots (dead hearts).
• Soil application of Carbofuran 3G @ 7–10 kg/acre in whorl.
• Foliar sprays of Chlorantraniliprole or Spinosad.
• Use resistant hybrids and timely sowing.

Pink Stem Borer – Sesamia inferens

More common in Rabi maize, especially in cooler environments.

Symptoms

• Pinkish larvae inside stem
• Internal tunneling
• Poor cob development
• Weak stems leading to lodging

Management

• Use early-maturing hybrids
• Seed treatment with Chlorantraniliprole
• Soil application of Fipronil granules
• Spray Emamectin benzoate for larvae control

Shoot Fly – Atherigona soccata

A serious pest in seedling stage.

Symptoms

• Dead hearts that can be easily pulled out
• Tillers may appear but remain unproductive
• Patchy appearance in fields

Management

• Timely sowing (avoid late sowing).
• Seed treatment with Imidacloprid / Thiamethoxam.

Soil application of Carbofuran or Fipronil.

Aphids – Rhopalosiphum maidis

These tiny insects suck sap from maize leaves and stems.

Symptoms

• Yellowing and curling of leaves
• Sticky honeydew deposits
• Sooty mold on leaf surfaces
• Reduced plant growth and cob formation

Management

• Spray Imidacloprid 17.8 SL @ 0.3 ml/l
• Encourage predators like ladybird beetles
• Avoid heavy nitrogen application (promotes aphids)

Corn Earworm / Helicoverpa

This pest attacks maize cobs at silking stage.

Symptoms

• Silk clipping
• Feeding inside cobs
• Boreholes on grains
• Cob rot in severe cases

Management

• Install pheromone traps
• Spray Spinetoram 11.7 SC or Emamectin benzoate

Termites

Found mostly in dry regions and sandy soils.

Symptoms

• Plants wilt suddenly
• Termite mud galleries at base
• Roots and stem eaten below the soil
• Plants uproot easily

Management

• Soil treatment with Chlorpyriphos / Fipronil
• Maintain soil moisture
• Mix FYM with Trichoderma

MAJOR DISEASES OF MAIZE

Turcicum Leaf Blight (TLB) – Exserohilum turcicum

A widespread fungal disease in humid and cool climates.

ymptoms

• Long, cigar-shaped greyish lesions
• Lesions enlarge and merge, drying entire leaves
• Plants lose photosynthetic ability → poor grain filling

Management

• Grow resistant hybrids
• Crop rotation with non-host crops
• Spray Mancozeb @ 2.5 g/l or Propiconazole @ 1 ml/l

Maydis Leaf Blight (MLB) – Bipolaris maydis

More common in warm, humid climates.

Symptoms

• Small, oval brown lesions with yellow margins
• Rapid spread due to favorable climate
• Early infection drastically reduces yield

Management

• Spray Carbendazim + Mancozeb
• Remove infected debris
• Grow tolerant varieties

Downy Mildew / Crazy Top – Peronosclerospora sorghi

A destructive fungal-like disease.

Symptoms

• Chlorotic streaks on leaves
• White downy fungal growth under the leaf
• Plants may become stunted
• Tassel becomes leafy instead of flowering (Crazy Top symptom)

Management

• Seed treatment with Metalaxyl
• Rogue infected plants
• Spray Metalaxyl + Mancozeb
• Ensure proper field drainage

Rust – Puccinia sorghi

A foliar fungal disease seen in late crop stages.

Symptoms

• Numerous reddish-brown pustules
• Pustules rupture to release spores
• Severe infection → premature drying of leaves

Management

• Spray Propiconazole @ 1 ml/l
• Avoid late sowing
• Remove volunteer maize plants

Banded Leaf & Sheath Blight – Rhizoctonia solani

This disease affects leaves, sheaths, and stalk base.

Symptoms

• Alternating light and dark 'banded' lesions
• Cottony fungal growth between sheath and stem
• Poor grain filling and shriveled cobs

Management

• Follow proper plant spacing
• Avoid field humidity and continuous maize cropping
• Spray Validamycin 3L @ 2 ml/l
• Apply Trichoderma in soil

Charcoal Rot – Macrophomina phaseolina

Common in drought-stressed maize.

Symptoms

• Plants wilt during cob formation
• Stalk splits easily
• Black sclerotia (charcoal-like particles) under stem bark

Management

• Irrigate during grain filling
• Apply farmyard manure + Trichoderma
• Avoid water stress and high plant density

Common Smut – Ustilago maydis

A fungal disease that produces characteristic galls.

Symptoms

• Tumor-like galls on leaves, stems, tassels, and cobs
• Galls filled with grey-black powdery spores
• Grain quality and marketability drop

Management

• Remove and destroy infected galls
• Seed treatment with Carbendazim
• Follow crop rotation and field sanitation

Conclusion

Maize is a high-investment crop, and preventing pest and disease damage is crucial for earning good profits. Regular field monitoring, use of resistant hybrids, seed treatment, biological control, and timely spraying of recommended chemicals can protect maize from major yield losses.
When farmers adopt an Integrated Pest and Disease Management (IPDM) approach, maize becomes far more resilient and productive.