Leaf Spot Disease (LSD) continues to be a major concern in arecanut plantations, prompting scientific interventions by leading institutions to support farmers with effective management strategies.
Central Plantation Crops Research Institute (CPRCI) and Keladi Shivappa Nayaka University of Agricultural and Horticultural Sciences launched three-year field demonstrations in June 2025.
It covers about 125 acres (50 hectares) across Dakshina Kannada, Uttara Kannada, Shivamogga, and Chikkamagaluru districts in Karnataka. The initiative aims to guide farmers through a comprehensive package of practices for disease management.
About Leaf Spot Disease (LSD)
Leaf Spot Disease is a pathological condition that weakens arecanut plants by disrupting Photosynthesis, thereby reducing plant vigor and productivity. Although initially a minor stress factor, prolonged infection across multiple growing seasons can severely impact plant health and yield.
Disease Spread: Primarily through wind, splashing rain, or irrigation water, which carry pathogen spores to susceptible tissues. It is mostly caused by fungi, though bacteria and other pathogens may also be involved. High humidity conditions or prolonged moisture on leaf surfaces (12–24 hours) significantly favour disease development.
Key Features and Identification
- Symptoms appear as angular or rounded spots, which may be raised or sunken with smooth or irregular edges.
- Spot coloration varies from yellow and orange-red to brown or black, depending on severity and stage.
- Initial infection is usually seen on lower and inner canopy leaves, where humidity is higher.
- Smaller spots indicate recent infections, while larger lesions often show fungal growth at the centre.
- Pathogens can survive in fallen leaf debris, buds, and twigs, enabling reinfection in subsequent seasons.
Management and Control Measures
Effective control requires an integrated package of practices rather than isolated treatments:
- Sanitation: Removal and destruction of fallen leaves to prevent pathogen carryover.
- Cultural Practices: Ensuring proper drainage, pruning to improve air circulation, and maintaining optimal plant spacing.
- Soil Health Management: Application of lime to correct soil acidity, along with balanced nutrients, micronutrients, and neem cake.
- Biological and Chemical Control:
- Use of Trichoderma to manage soil-borne infections.
- Spraying Bordeaux mixture during monsoon conditions.
- Targeted fungicide application such as Propiconazole, Tebuconazole, or Propineb after removing infected plant parts.