1. Importance of Proper Spacing
Correct spacing in Aquilaria plantations directly affects:
- Tree health and growth rate
- Root distribution and nutrient uptake
- Resin induction accessibility
- Disease spread prevention
- Long-term plantation productivity
- Resin yield quality (light exposure influences sesquiterpene profiles)
Overcrowded trees = slower growth + higher disease incidence
Under-spaced plots = wasted land + lower total yield
2. Recommended Spacing Options
A. Standard Commercial Planting
3 × 3 meters
- 1,111 trees per hectare
- Best for balanced growth and induction access
- Suitable for commercial agarwood chip & oil production
- Allows sufficient canopy expansion for resin formation
B. Low-Density Premium Resin Production
4 × 4 meters
- 625 trees per hectare
- Better light penetration = improved resin biochemistry
- Ideal for inoculation requiring repeated access
- Reduced fungal/disease pressure
C. High-Density Early Yield Systems
2 × 2 meters
- 2,500 trees per hectare (short-term)
- Used in farmer-based models
- Thinning required at year 3–5
- Fast canopy closure → early biomass but higher risk of disease if unmanaged
D. Strip Planting for Agroforestry
2–3 m spacing within row × 5–7 m between rows
- Integration with crops or livestock
- Allows machinery and sunlight penetration
- Supports intercropping or pathways
3. Recommended Planting Patterns
A. Square Planting (Most Common)
3 m × 3 m grid
- Easy for farm mapping
- Uniform growth
- Ideal for block plantations of 1–100 hectares
B. Rectangular Planting
3 m × 4 m or 4 m × 6 m
- Facilitates walkway and vehicle access
- Suited for large mechanized plantations
- Better ventilation → reduced pathogen risk
C. Triangular (Hexagonal) Pattern
- 15% more trees per hectare
- Optimizes sunlight distribution
- Promotes faster early growth
Used for premium production blocks where space optimization is key.
D. Contour Planting (Hilly Areas)
- Follows land contours to reduce soil erosion
- Spacing: 3–4 m apart along contour lines
- Particularly useful in upland Luzon, Visayas, and Mindanao plantations
4. Agroforestry Integration Models
A. Intercropping with Short-Term Crops
During years 1–3 when Aquilaria canopy is still open:
Suitable Crops:
- Ginger, turmeric, lemongrass, galangal (aromatic crops)
- Peanut, mungbean, cowpea (nitrogen-fixing legumes)
- Pineapple, banana, and papaya (partial shade tolerant)
Benefits:
- Additional income
- Weed suppression
- Soil fertility improvement (with legumes)
Spacing recommendation:
Aquilaria 3×3 m + crops planted between rows
B. Alley Cropping System
Rows of Aquilaria alternated with agricultural crops.
Example layout:
Row spacing: 6 m between Aquilaria belts
Tree spacing within row: 3 m
Alleys: vegetables, corn, root crops, or legumes
Benefits:
- Diversified revenue
- Light distribution improvement
- Soil erosion mitigation
C. Mixed Tree Farming
Compatible tree species:
- Sandalwood (Santalum album)
- Cinnamon (Cinnamomum verum)
- Citrus spp.
- Ylang-ylang (Cananga odorata)
- Narrah (timber species)
Guidelines:
- Maintain 4–6 m lateral distance between species
- Ensure light-demanding species are placed strategically
- Avoid species that host Aquilaria pests (e.g., certain fruit trees)
D. Shade-Based Agroforestry
For humid zones or early-stage plantations:
Use temporary shade trees:
- Gliricidia sepium
- Erythrina orientalis
- Leucaena leucocephala
Functions:
- Microclimate regulation
- Nitrogen fixation
- Protection during first 2 years
Remove or prune shade trees as Aquilaria matures.
5. Farm Layout Guidance
A. Access Pathways
- 2–3 m service roads every 50–100 m
- Essential for induction, monitoring, and harvest activities
B. Water Access
- Irrigation channels if rainfall < 1,800 mm/year
- Drip system preferred for water efficiency
C. Inoculation Zones
Design compartments for:
- Sequential induction cycles
- Controlled microbial application
- Resin yield monitoring
6. Best Practices
✔ Use high-quality seedlings (≥ 30–45 cm tall)
✔ Plant at onset of rainy season for best survival
✔ Maintain 1-year weed control period
✔ Apply organic matter to enhance early growth
✔ Avoid overly dense planting to prevent disease
✔ Prune branches to promote a strong trunk
✔ Create GIS-based mapping/logging for professional plantations