Smoke spreading (also called smoke fumigation or smoke sanitation) is one of the oldest and most practical field techniques used in plantation crops to reduce pest activity, suppress fungal diseases, and improve carbon dioxide circulation within the crop canopy. Although modern farming relies heavily on chemicals and biologicals, controlled smoke remains an effective, low-cost support method—especially in crops like coffee, pepper, arecanut, cocoa, rubber, coconut, and fruit orchards. When done correctly, it enhances plant health without harming the environment.
How Smoke Works in Plantation Systems
Most plantation crops have dense canopies, shaded understories, and humid microclimates. These conditions allow insects, fungal spores, and mites to thrive quietly. It modifies this microclimate in two key ways:
- Acts as a Natural Pest Repellent
Many flying insects—such as whiteflies, psyllids, aphids, thrips, and moths—avoid smoky or hazy environments because it disturbs their navigation. The aroma compounds generated from burning organic material (dry leaves, coconut husk, coffee husk, wood powder, etc.) also act as mild repellents. Regular smoke exposure forces pest colonies to shift, reducing their population and preventing new infestations from settling. - Suppresses Fungal Spores and Moisture Levels
Plantation crops often suffer from diseases such as black pepper wilt, coffee leaf rust, berry diseases, and bud rot in coconut. Fungal spores thrive when humidity is high and air movement is low. Smoke slightly dries the air, reduces dew formation, and prevents the germination of airborne spores. It does not kill the fungi completely, but it significantly slows their development and spread.
Importance of Carbon Dioxide Circulation
During controlled smoke generation, the burning organic matter releases carbon dioxide (CO₂), which temporarily increases the CO₂ concentration around the crop. This has three major benefits:
- Stimulates Photosynthesis
Plantation crops respond positively to mild increases in CO₂, especially during early morning or late afternoon. Enhanced CO₂ availability helps leaves produce more carbohydrates, leading to better growth, improved vigor, and stronger resistance against stress. - Creates Vertical Air Movement
The rising smoke column pushes stagnant air upward and draws fresh air into the lower canopy. This improves overall ventilation, reducing excess humidity and encouraging healthier leaf surfaces. - Strengthens Plant Physiology
CO₂ enrichment supports the opening and closing balance of stomata, enabling plants to regulate heat, moisture, and nutrient exchange more efficiently. This directly contributes to better yield and resilience.
Sulphur Fumigation Pest & Disease Management
fumigating sulphur smoke can be helpful in managing certain fungal diseases and pests, especially in plantation crops, nurseries, polyhouses, and storage areas. It works because sulphur, when burned, releases sulphur dioxide (SO₂), which has fungicidal and insect-repellent properties.
Advantages:
- Effective Against Fungal Diseases
- Controls powdery mildew, leaf spot fungi, and other air-borne fungal spores.
- Helps reduce disease spread in closed or semi-closed environments.
- Repels Certain Pests
- Acts as a repellent for mites, thrips, and small insects.
- Reduces pest build-up during storage and in nurseries.
- Improves Air Sanitation
- Helps disinfect the air by reducing fungal spore load.
- Useful in polyhouses, curing sheds, drying rooms, and spice storage areas.
Disadvantages / Risks:
- Best suited for post-harvest spaces, storage, or closed structures.
Health Hazards to Humans
- SO₂ gas can irritate:
- eyes
- throat
- lungs
- Must avoid staying inside the fumigation area.
- sts like borers, beetles, caterpillars, etc.
- Overuse can increase air pollution and contribute to soil acidity.
How to Apply Smoke Safely in the Field
For effective results, smoke must be generated in a controlled, slow-burning manner:
- Use dry leaves, wood dust, coconut husk, sawdust, or organic farm waste.
- Avoid plastics, painted wood, rubber, or chemicals that release toxic fumes.
- Place smoke piles in small heaps with airflow restricted enough to produce thick, cool smoke rather than flames.
- Create smoke during early morning or evening to avoid high winds.
- Ensure smoke drifts slowly through the crop rows for 20–30 minutes.
- Maintain a safe distance from buildings and avoid excessive smoke that may affect workers or neighbors.
When to Use Smoke Spreading
Smoke can be used throughout the year depending on crop conditions:
- During high humidity periods, such as monsoon months, to reduce fungal activity.
- In pest outbreak seasons, especially when whiteflies, thrips, or leaf miners become active.
- Early morning foggy conditions, to dry the leaf surface and prevent disease onset.
- After small pruning operations, to reduce insect attraction to fresh wounds.
- Before applying organic sprays, helping pests disperse and improving spray coverage.
Limitations and Precautions
Although highly beneficial, smoke spreading should not replace scientific disease management. It is best used as a supportive cultural practice along with sanitation, proper nutrition, mulching, and integrated pest management (IPM). Over-smoking can reduce oxygen levels in closed environments, so ventilation must be monitored. Workers should stand away from direct smoke inhalation.
Conclusion
Smoke spreading is a traditional practice with strong scientific relevance. By altering the microclimate, repelling pests, limiting fungal spread, and improving CO₂ circulation, it enhances the overall health of plantation crops. When combined with modern agronomic practices, it becomes a powerful, eco-friendly strategy to safeguard plantations and promote sustainable yields
