Maize Turcicum Leaf Blight Control

Symptoms

Long, narrow, boat or cigar shaped greyish green to tan lesions appear on the leaves, usually starting on the lower leaves and spreading upward. The spots enlarge and join together, and in severe cases large parts of the leaf dry up and look scorched or burnt. The disease is favoured by moderate temperatures and high humidity with frequent dew or rain.

Damage

Turcicum leaf blight is one of the most important maize diseases in India, especially in cooler hill and high rainfall areas. By destroying leaf area before and during grain filling it reduces photosynthesis and causes poor cob and grain development, with yield losses commonly of 30 to 50 percent and higher when it strikes early on susceptible hybrids.

Organic & cultural control

Grow resistant or tolerant hybrids recommended for your area as the main control. Follow crop rotation away from maize and plough in or remove infected crop residue which carries the fungus to the next season. Avoid very dense planting and excess nitrogen that keep the canopy humid, ensure good drainage and field sanitation, and remove lower infected leaves early where practical.

Chemical control

If the disease appears early and is spreading, spray a registered fungicide such as mancozeb 75 WP, or a combination like azoxystrobin plus difenoconazole, ensuring good coverage of the foliage and repeating as per label. Always follow the product label dose, observe the pre harvest interval and consult your KVK or agronomist before spraying.

Always follow the product label, the recommended pre-harvest interval, and your local KVK or agronomist. Pesticide approvals change, so verify before use.

Prevention

Choose resistant hybrids, rotate crops and manage residue by deep ploughing or removal. Sow at the recommended spacing, balance fertiliser, avoid waterlogging and keep fields and bunds clean. In high risk hill and humid regions plan a preventive fungicide schedule with your KVK based on past disease history.