Qualification Level: TESDA NC I – Sustainable Plantation Management
Crop Focus: Agarwood (Aquilaria spp.)
Objective: Understand how organic amendments reduce plant disease risk and promote soil health
I. PRINCIPLES
- Healthy soil = healthy plants – Disease suppression begins with biologically active, nutrient-rich soil.
- Organic amendments (compost, biofertilizers, mulches, green manures) improve:
- Microbial diversity
- Soil structure and aeration
- Nutrient availability
- Plant defense mechanisms
- Suppressive soils – Soils rich in beneficial microbes can outcompete pathogens or produce inhibitory compounds.
II. HOW ORGANIC AMENDMENTS SUPPRESS DISEASES
| Mechanism | Description | Example |
|---|---|---|
| Competition for space and nutrients | Beneficial microbes occupy root zone, reducing pathogen establishment | Biogrow N-fixers outcompeting Fusarium in soil |
| Production of antimicrobial compounds | Microbes produce enzymes, antibiotics, or organic acids that inhibit pathogens | Trichoderma spp. secreting chitinase against fungal pathogens |
| Induced systemic resistance (ISR) | Certain microbes stimulate plant immune response | Mycoboost fungi triggering root and stem defenses |
| Improved soil structure & drainage | Reduces waterlogging and root rot incidence | Compost-amended soil with better porosity |
| Enhanced organic matter decomposition | EcoZyme accelerates breakdown of residues, preventing pathogen buildup | Faster conversion of leaf litter reduces fungal inoculum |
III. TYPES OF ORGANIC AMENDMENTS FOR DISEASE SUPPRESSION
| Amendment | Function | Application Tips |
|---|---|---|
| Compost | Adds beneficial microbes, humic substances | Apply 2–5 cm layer around tree base; incorporate lightly into soil |
| Biofertilizers | Introduce N-fixers, P-solubilizers, mycorrhizae | Drench roots or apply via irrigation every 2–3 weeks |
| Mulches / Leaf litter | Conserves moisture, enhances microbial diversity | Keep 5–10 cm around tree base; avoid trunk contact |
| Green manures / cover crops | Increase microbial activity and organic matter | Grow between rows; plow in before flowering or inoculation |
| Compost teas / fermented extracts | Increase microbial antagonists in soil and on foliage | Foliar or soil drench applications; avoid direct sun exposure during spraying |
IV. BENEFITS FOR AGARWOOD
- Reduces incidence of Fusarium wilt and root rot
- Limits foliar diseases like anthracnose and powdery mildew
- Improves tree vigor and root system health
- Supports controlled resin induction by maintaining stress-resilient plants
- Reduces reliance on chemical fungicides
V. INTEGRATION WITH IRRIGATION
- Apply amendments when soil moist but not waterlogged
- Drip or basin irrigation enhances colonization of beneficial microbes
- Mulch retains soil moisture and prolongs microbial activity
VI. BEST PRACTICES
- Use high-quality, well-composted materials
- Apply at recommended doses – too much can create anaerobic conditions
- Combine biofertilizers with organic matter for synergistic disease suppression
- Maintain good sanitation – remove heavily diseased plant parts
- Monitor soil pH (optimal 5.5–6.8) for microbial activity
VII. TESDA NC I PERFORMANCE STANDARD
Learner must demonstrate ability to:
- Identify organic amendments that suppress plant diseases
- Apply amendments correctly in nursery and field
- Explain mechanisms by which amendments reduce pathogen incidence
- Monitor plant and soil health for disease prevention
VIII. FARMER-FRIENDLY CHECKLIST
☐ Apply compost or organic mulch around trees
☐ Use biofertilizers to enhance soil microbial diversity
☐ Maintain soil moisture suitable for microbial activity
☐ Remove diseased plant parts promptly
☐ Avoid overuse of chemical pesticides
☐ Monitor tree vigor and root health regularly
This module ensures Agarwood trees remain healthy, soil biology is enhanced, and disease incidence is minimized naturally, supporting resin quality and sustainable production.