Cercospora Leaf Spot Management in Chilli Pepper: Symptoms, Identification, Treatment, Chemical, Biological, Natural, and Organic Control

Cercospora leaf spot is a common fungal disease that affects Chili plants, causing significant yield losses in many regions of the world. The disease is caused by the fungus Cercospora capsici. The presence of small, circular, brownish-black spots on the leaves can identify it. Over time, the spots can coalesce and cause the leaves to turn yellow and drop prematurely.

Cercospora Leaf Spot Management in Chilli Pepper

Cultural, chemical, and biological approaches manage the Cercospora leaf spot. Crop rotation, sanitation, and irrigation restrict disease spread. To prevent fungicide resistance, change fungicides with different ways of action. Microbial biocontrol agents and plant products can also manage the Cercospora leaf spot in Chili plants. Developing disease-resistant Chili cultivars can also aid.

Cercospora Leaf Spot Management in Chilli Pepper

Causes/Pathogen of Cercospora Leaf Spot in Chilli

Cercospora leaf spot is caused by a fungus known as Cercospora capsici, which thrives in tropical regions and can affect Chili plants in seedbeds and fields. Stromata are fully formed. Conidiophores measure between 30 and 60 x 4.5 and 5.5 microns. Conidia are acicular to obculate, and subhyaline to colored.

The fungus can survive from one growing season to the next in various ways, including on infected plant residues, in the soil, and even on or inside seeds. Once a plant is infected, the fungus causes characteristic brownish-black circular spots on the leaves, which can eventually cause the leaves to turn yellow and fall off prematurely. 

The Disease Cycle of Cercospora Leaf Spot in Chilli

Cercospora leaf spots in Chili spread through various means, such as water, rain, wind, and contact between leaves or contaminated tools and workers. The disease cycle begins with the dormant mycelium of the Cercospora capsici fungus surviving in infected plant debris, seeds, and volunteer plants during the dormant season.

In the growing season, the disease spreads via air-borne conidia dispersed by wind. The primary source of infection is infected seeds, volunteer plants, and infected plant debris. Foliar infection occurs when the fungus penetrates the leaf directly, which is facilitated by prolonged leaf wetness.

Conditions Favorable for Cercospora Leaf Spot Spread in the Field 

Cercospora leaf spot in Chili thrives under certain conditions that favour its spread in the field. The optimal conditions for infection include warm temperatures around 23°C and relative humidity of 77-85%. When these conditions are met, there is a high likelihood of significant yield losses, especially if the infection occurs early in the season. Foliar infection occurs when the fungus directly penetrates the leaf, facilitated by prolonged periods of leaf wetness.

Damage Symptom