Effect of Coconut Shell Liquid Smoke on Cocoa Seedling growth and soil improvement (Crop Research Journal, 2024).

In 2024, significant research was published in Research on Crops (and associated repositories like ResearchGate) by Agusalim Masulili et al. regarding the use of coconut shell liquid smoke in cocoa cultivation. The study specifically investigated how this organic byproduct could revitalize Ultisols—acidic, nutrient-poor soils common in tropical cocoa-growing regions.

Here is a breakdown of the core findings and strategies from the 2024 research:

📈 1. Impact on Cocoa Seedling Growth

The study found that applying liquid smoke at a specific concentration significantly boosts the physical development of young cocoa plants compared to untreated seedlings.

• The Optimal “Sweet Spot”: A concentration of 0.75% liquid smoke was identified as the most effective for maximizing growth.
• Key Growth Metrics (at 12 weeks):
  • Plant Height: Reached an average increase of 29.09 cm.
  • Leaf Count: Averaged an increase of 14.08 leaves.
  • Stem Diameter: Showed a significant increment of 9.87 mm.
• Physiological Stimulant: The researchers noted that the acetic acid and organic acids found in liquid smoke act as natural biostimulants, accelerating metabolic processes and photosynthetic capacity in the seedlings.

🛠️ 2. Soil Improvement in Ultisols

Ultisols are notoriously difficult for cocoa due to high acidity and low organic matter. The 2024 research highlights how liquid smoke acts as a “corrective” agent:

• Chemical Properties: Liquid smoke contains phenols, carbonyls, and organic acids. When applied to the soil, these compounds help in improving the availability of trapped nutrients.
• Disease Suppression: The phenolic compounds (guaiacol, phenol, and pyrogallol) serve as natural antioxidants and antiseptics. They suppress soil-borne pathogens and fungi (like Phytophthora sp.) that typically cause root rot in cocoa.
• pH Balancing: While liquid smoke itself is acidic (pH ~2–3), in the complex chemistry of Ultisols, its application can help stabilize soil aggregates and create a healthier microbial environment for nutrient uptake.

🧪 3. Application Protocol

According to the study’s methodology, the best results were achieved using the following schedule:

📊 Why Coconut Shell specifically?

The 2024 studies (including work in the Journal of Scientific Multidisciplinary Research) confirm that coconut shells are superior to other biomasses (like rice husks or rubber seeds) because their dense lignin-cellulose structure produces a “Grade 1” liquid smoke that is richer in bioactive compounds and more effective at lower doses.

Research Verdict: Using 0.75% coconut shell liquid smoke provides a low-cost, sustainable alternative to synthetic growth regulators. It not only accelerates the “nursery stage” of cocoa production but also builds the seedling’s resistance to environmental stress.