Comprehensive Guide to Corn Leaf Blight Treatment

Northern Corn Leaf Blight (NCLB) is a dreaded foliar corn diseases, referred to as Exserohilum turcicum and is one of the most imperative factors diminishing corn yield globally. This neglected tropical disease is mainly affecting the areas with cool and wet climates, e. g.  the USA, Africa, Latin America, China and India. NCLB is marked with long cigar-like cuts, extending over leaves of the corn plants, thereby causing loss in photosynthetic efficiency and finally yield. Continue reading the blog to know corn leaf blight treatment.

Crop management of NLCL is multifaceted and involves the use of resistant hybrids, efficient residue management which reduces spore contamination and application of fungicides during mortal crop phases. Regular monitoring and prompt control procedures will be one of the best solutions for reducing this rice’s effect on the corn crops.

What does Northern Corn Leaf Blight Look like?

Northern Corn Leaf Blight (NCLB) is identifiable for its long lesions positioned on the corn leaves that can be easily seen with just a glance. The lesions are usually less than 10 cm long and have a characteristic light-grey to brown-tan color, with the border of the lesion being darker in most cases. 

The early diseased stages will have a wet look at first and then the spots will turn pale green as they develop, eventually becoming necrotic brown or cheesy tan as the disease spreads. At high humidity conditions and moderate temperatures ranges, these sores can quickly increase in size, resulting in a great number of affected leaf surfaces. This extensive damage completely impedes the ability of plants to photosynthesis, thereby leading to lack of vigor and the possibility that it might result in yield losses. 

The blight can sometimes extend to more severe cases and lead to widespread inconspicuousness of foliage.  The leaves may appear early, and significantly damaged. This may result in drastic structural changes within the corn crop.Leaf blight causes the plant health to deteriorate and also its economic value.  Early detection and proper management are thus vital.

Northern Corn leaf blight symptoms

Exserohilum turcicum which causes Northern Corn Leaf Blight (NCLB) is a common disease that impacts corn production. The main manifestations of NCLB include the formation of long, elliptical, grayish-green to tan spots on the foliage. These lesions can measure from 1 to 6 inches in length and are most often cigar shaped with long axes parallel to the veins of the leaf. These gradually become necrotic and over time the lesions may join up to form large areas of dead tissue also known as blanch. 

At severe conditions, the lesions as mentioned above may occupy most of the area on the leaf’s surface, therefore causing early leaf senescence and relatively large amount of yield reduction. The initial part affected is the lower foliage with the disease progressing upwards in its spread as shown in fig. For NCLB to occur, there are conditions that must prevail, these conditions include, long periods of leaf wetness, high humidities, and moderate temperatures enhance the releasing and spread of the fungal spores. It is very imperative to identify these symptoms early and apply the right measures in order to reduce the effects of NCLB on corn production.

What does Southern Corn Leaf Blight Look like?

Southern Corn Leaf Blight (SCLB), caused by Bipolaris maydis, primarily affects corn plant foliage with small tan to brown spots. The disease appears in the interveinal area, with lesions that may look water-soaked in their initial stage. As SCLB progresses, lesions enlarge and merge, often leading to extensive leaf blighting and significant plant damage. This blighting can result in localized necrosis or complete leaf death, reducing the plant’s photosynthetic capacity. Affected crops typically exhibit low vigor and yield, significantly impacting overall productivity. SCLB thrives in warm, humid conditions, spreading effectively through wind and rainborne spores. Early recognition of symptoms is crucial for timely disease control and treatment in corn plants.

Southern Corn leaf blight symptoms

• Lesion Appearance: The most distinct symptom is the willowy, cigar-shaped lesions on the leaf with a grey to a brownish color usually being around one to six inches in length. 
•  Early Symptoms: Initially the margins of spots can become necrotic in a fresh watery green coloration, but later they will become more similar to the characteristic necrosis.
•  Progression: As the disease advances, the lesions will enlarge and coalesce, being able to cover a whole great part of the leaf. This means that the photosynthetic area does decrease considerably, which then can affect the proper functioning and development of the plant. 
•  Advanced Symptoms: In severe cases, the blight can result in damage from the leaves appearing diseased and dried with general coloration and a dying back of the leaves.

 

Southern Corn leaf blight treatment

An integrated strategy that includes chemical, cultural, and biological tools is needed to cope with northern corn leaf blight (NCLB) of corn. Each method brings about inherent benefits and, when used together, provide the best outcome which could be achieved in this invasive fungal disease control endeavor. 

Chemical Control: 

Chemical best fungicide for leaf blight have been in use for a long time as a primary strategy in the control of NCLB. Effective fungicides commonly have binders made up of strobilurins (a common active ingredient). g. , azoxystrobin), triazoles (e. g. The active ingredient can be a shunt (e. g. , propiconazole), a whole tissue die-out (e. g. , urea), or the combination of different modes of action. 

These chemicals have the highest efficacy when they are used in a preventative manner, before the disease has been already developed. Perfect timing is essential; applicants should go along with disease commencement at the early stages prior to tasseling. Continual weather conditions observation should be given emphasis particularly on humidity and temperature that favors NCLB spread so control application is well timed. Nevertheless, relying only on the chemical controls will bring resistance; so, it is better to assimilate with the other management method to sustain the practice. 

Cultural Practices: 

Cultural control methods can reduce inoculum and inhibit disease spread within a plant population. Practices like crop rotation help break disease cycles by reducing dead spore quantities in the soil. Tillage for weed management decomposes infected plant debris, treating soil and reducing fungal spore presence. This soil treatment must balance with soil conservation to maintain long-term soil health. Planting resistant corn varieties with Ht genes is an effective tactic against diseases like SCLB. These genetically resistant plants transform the disease into a less harmful condition. Adjusting planting dates and densities can reduce leaf wetness, discouraging disease proliferation in the field.

Biological Methods: 

The introduction of biological controls represents one more eco-friendly modality into the NCLB control remedy. Leaf blight fungicide, Trianum V, is a biological agent that either stops fungal growth or makes the plants have a stronger resistance to biological agents. This best fungicide for leaf blight has a natural ingredient that is good for both the conventional and organic farming scenarios. Further details like usage guide and the method of application can be ascertained from the Novobac Natural Fungicide page. 

Metilo, for example, those by Novobac, on the other hand, also carry a lot of weight in disease management. These substances are boosting up plant resilience and are actually giving him less chance to have NCLB infections. Novobac’s biostimulant supports better absorption of nutrients, favorable growth environmental conditions and so the plant is more fortified to ward off infections. For more information, please visit the page devoted to Novobac Biostimulant. 

 These practices when combined will not only make it easier to control NCLB but also achieve an environmentally sustainable agricultural practice. It’s important to have a routine of consulting with agricultural extension services and stay updated on the current research to course-correct for the emergence of new strains of the fungus or changes in the environment that might affect disease spread. Integrated disease management does not only help farmers to keep their crops from NCLB but also ensures more crops and the longevity of the field in the future.

References:

1. WANG, Shao-qing, et al. “Combined application of Trichoderma harzianum SH2303 and difenoconazole-propiconazolein controlling Southern corn leaf blight disease caused by Cochliobolus heterostrophus in maize.” Journal of integrative agriculture 18.9 (2019): 2063-2071.
2. Limdolthamand, Supharoek, et al. “Biocontrol efficacy of endophytic Trichoderma spp. in fresh and dry powder formulations in controlling northern corn leaf blight in sweet corn.” Biological Control 181 (2023): 105217.