The Maize Leaf Blight Disease is a destructive fungal disease of maize crops caused by the Ascomycota pathogens and is also known as northern corn leaf blight or southern corn leaf blight. The fungus can affect plant parts, such as the stalk, ears, and grains. It is important to understand the parameters that contribute to disease development.
Maize leaf blight can be managed through resistant varieties, fungicide applications, and crop rotation. To effectively manage this disease, it is important to understand its disease cycle, the mode of disease spread, and the best methods for controlling it. This article will provide an overview and discussion of the Maize Leaf Blight Disease in Maize crops, including its symptoms, identification techniques, and control.
Maize Leaf Blight Disease Management in Maize
The Causal Organism of Maize Leaf Blight Disease
- Exserohilum turcicum (Helmithosporium turcicum) and Bipolaris maydis (Cochliobolus heterostrophus or Drechslera maydis or Helminthosporium maydis) are the commonly distributed leaf blight pathogens. They belong to the Family Pleosporaceae, Order Pleosporales of the Phylum Ascomycota.
- The pathogen Exserohilum turcicum causes Northern Corn Leaf Blight Disease, whereas Bipolaris maydis causes Southern Corn Leaf Blight Disease in maize.
- They are unique diseases caused by separate funguses with common symptoms of elongated grayish-green to tan lesions on the leaves of maize crops.
The Disease Cycle of Maize Leaf Blight Disease
The disease cycle begins when the conidia of the pathogen primarily spread from soil and dormant mycelium in infected seeds. And the secondary spread occurs by many different mechanisms when the conidiophores are spread by wind, splashing rain, and contact with infected plants.
The respective fungal pathogens produce geniculate conidia on the conidiophores in which every conidium has 7-11 septa. The conidia infect the hosts via wind and begin to infect the host by bipolar germination in free water on the leaves. The symptoms begin to show within 1-2 weeks of infection. The teleomorph or perfect stage of H. turcicum is Trichometasphaeria turcica, and of H. maydis is Cochliobolus heterostrophus Drechsler, during which they form the fruiting body perithecia comprising of Asci and ascospores inside.
Occurrence of Maize Leaf Blight Disease in Maize Crop
- Location of Maize Leaf Blight disease: This disease is observed in countries like the USA, the UK, Mexico, Argentina, Brazil, Germany, Colombia, Peru, Ecuador, Africa, Afghanistan, Bangladesh, China, India, Indonesia, New Zealand, Korea, Sri Lanka, Thailand, and Australia.
- Host range: The crops susceptible to leaf blight are wheat, rye, barley, oats, sorghum, seeds of green gram, black gram, cowpea, varagu, Sudan grass, Johnson grass, and Teosinte. The disease can be spread to other vegetable crops like tomatoes, potatoes, peppers, eggplants, and cruciferous vegetables such as cabbage and broccoli.
Favorable Conditions for Maize Leaf Blight Disease Spread in the Field
- Humid, rainy, windy, and warm weather is favorable for the growth and spread of the disease in the cornfield.
- The fungus thrives in Temperatures between 18-2