Pengelolaan Resiko Biotik HPT di Hutan oleh Dr. Budi Tjahjono

Scientific Concepts / Nature Phenomena Presented

Industrial Plantation Forestry Systems

• Industrial plantation forest management (HTI) includes cultivation of:
  • Eucalyptus and Acacia.
• Planting details mentioned:
  • Eucalyptus planted on mineral soil / “grillland” areas
  • Acacia planted on peat land
• Nursery production scale:
  • 600 million seedlings per year
  • Targeting 300,000 ha/year in Sumatra and Kalimantan

Productivity Losses From Biotic Disturbance

Biotic risks (pests, diseases, weeds) in plantations are described as:

• Very large
• Age- and species-dependent

Reported yield/productivity reductions (examples):

• Weeds
  • Uncontrolled weeds can reduce eucalyptus productivity up to ~40%
  • Eucalyptus is less able to compete with weeds than acacia
• Pests / diseases (general and specific examples)
  • Weeds overall: roughly 10–20% productivity reduction (general statement)
  • Acacia disease example:
    • Reduces productivity up to ~28%, especially with root rot

Age-Dependent Pest/Disease Risk

Pest shifts with plant age

• Leaf roller caterpillars: most detrimental early (up to ~3 months)
• Later stages:
  • Helopeltis
  • then stem borers
  • later termites

Disease shifts with plant age

• Root rot and heart rot:
  • risk increases from around ~1 year onward
• Some diseases (e.g., “keramises/ceramises-like”):
  • more problematic before 1 year
  • later plant resistance increases

Specific Pest Examples and Ecology

Eucalyptus pests

• Leaf caterpillars / leaf-roller type pests
  • Resistance varies among eucalyptus clones
• Termites and shifting risk dynamics
  • Eucalyptus is generally less favored by some termite groups (contrasted with acacia)
  • A “new, dangerous termite” in East Kalimantan attacks eucalyptus
  • Risk can shift dynamically (described as changing from “yellow to red” and back depending on resistance)
• Monkeys
  • Long-tailed and short-tailed monkeys damage plantations
  • Especially severe for acacia
  • Eucalyptus damage described as less preferred, but feeding behavior can still spread issues
• Squirrels
  • Mentioned as additional pests
• Stem borers / ring borers
  • Ring borers tunnel in a circular pattern
  • Entry wounds become infection points for fungi (fungal names appear garbled in subtitles, but the mechanism is clear)

Additional pest context

• Bronze pest / “bronz” (Brazil example)
  • Noted later in biological control context, where HTI becomes dry/brown

Disease Examples and Diagnostic Concepts

Bacterial wilt

• Significant in eucalyptus
• Pathogen name shown as:
  • Rastonia solanacearum (subtitles: “rastonia solanar”)
• Wilt symptoms include:
  • Wilting/drying
  • Internal stem vascular color change (“change in color inside the stem”)

Root rot / heart rot complex (Ganoderma focus)

• Central genus mentioned:
  • Ganoderma (subtitles appear as “ganderma/ganoderma” and also “Guderma”)
• Signs include:
  • Fruit bodies (Ganoderma basidiocarps) on stems/roots
  • Mycelial threads on roots
  • Rot underneath bark
• Comparison mentioned:
  • Differences between Ganoderma vs Pelinus/Pelinus-like fungi (growth on media and field morphology)

Stem rot disease example (“Stratocystis”-like)

• Internal black lines
• Characteristic odor described as “tape”-like

Acacia leaf spot disease

• Pathogen described as “Pasalora” (name garbled in subtitles)
• Host specificity and timing:
  • Strongly affects acacia, especially on peat land
  • Strongest impact on young plants < 1 year
• Microscopic signs:
  • conidia / “bonidia”
  • tube-like spore structures (“tube mace”)
• Fruiting/spore stage mention:
  • spore phase and perithecia referenced

Long-Term Trials and Resistance

• Multi-year experiment (~6 years):
  • Acacia survival decreases over time due to Ganoderma
    • Example: only ~14% alive by year 6
  • Eucalyptus survival is higher
    • Example: ~74% alive by year 6
  • Operational implication:
    • Switch away from acacia in areas with high Ganoderma
• Clone-level differences emphasized:
  • Some eucalyptus clones are susceptible to specific fungi; others resistant
  • Example disease mentioned: Kiramyces destructans (subtitles garbled), used to illustrate susceptibility vs resistance

Integrated Pest and Disease Management (IPM) / Risk Management Framework

IPM subsystems (3-part structure)

IPM is described as three subsystems:

1. Prevention
2. Monitoring
3. Control

“Four Control Principles” (shield model)

• Exclusion: prevent pests/pathogens entering the area (and prevent new introductions)
• Eradication: eliminate new/small outbreaks early
• Protection: protect vulnerable plants (e.g., greenhouse methods, protective fungicides)
• Resistance (resilience): plant resistant/tolerant varieties or clones (“best” / “deepest shield”)

Monitoring Approaches and Decision-Making

Monitoring includes:

• Visual field monitoring
• Plant sampling
• Records/reporting
• Pest traps
• Drones/satellites to detect abnormalities, followed by ground checks to confirm cause

Decision logic described:

• If natural enemies (predators/parasitoids) are functioning well → rely on them
• If not → intervention
• Chemicals are a last resort

Control Tactics Used in Practice

Termite control (Mechanical + Chemical)

• Example method called FDC:
  1. Find the nest
  2. Destroy mechanically
  3. Apply insecticides/spraying until nests are eliminated in the mapped area

Chemical application logistics

• Tall trees require specialized equipment (e.g., telescopic sticks/boosters)
• Drone application may be used for canopy pests

Biological control (fungi, bacteria, entomopathogens)

• Endophytic bacteria for bacterial wilt
  • An endophytic bacterium inside plant tissue competes with bacterial wilt pathogen (BWD)
  • Practical application: dip seeds/seedlings with a bacterial suspension in the nursery
• Trichoderma (and related antagonists) vs Ganoderma
  • Trichoderma inhibits Ganoderma growth
  • Streptomyces also mentioned as inhibiting Ganoderma in lab tests
  • Production: multiply Trichoderma on media, apply in nursery/field
• White-rot fungi
  • Degrade wood first, reducing substrate for Ganoderma
• Entomopathogenic fungi
  • Infect caterpillars/grubs (names garbled in subtitles, but the mechanism is infection of insect pests)
• Natural enemies for insects
  • Parasitoids (parasites that feed on other insects) to reduce pest populations
  • Predators (e.g., ladybugs/certain beetles; “Sikanus” mentioned)
  • Example strategy: multiply and release natural enemies to reduce leaf caterpillar populations

Use of Technology and Constraints

• Drones/satellites enable faster, more real-time monitoring
• Requires ground truthing
• Constraint noted:
  • Limited manpower willing to work in very large HTI areas

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Lists / Methodologies Outlined

IPM Subsystems (Framework)

• Prevention subsystem
• Monitoring subsystem
• Control subsystem

Control Principles (“4 Shields”)

• Exclusion
• Eradication
• Protection
• Resistance (resilience)

Monitoring and Decision Workflow (Conceptual)

• Monitor (visual + sampling + traps; possibly drones/satellites)
• Evaluate economic impact
  • If minor → no action; continue monitoring
  • If harmful → implement control
• Check whether natural enemies (predators/parasitoids) are working
  • If effective → rely on natural enemies
  • If not → intervention; chemicals only as last resort

Termite Pest Control Method (FDC)

• Find nest location
• Destroy mechanically
• Control using insecticide spraying until nests are eliminated

Biological Control Approaches Mentioned

• Endophytic bacteria for bacterial wilt
  • Produce bacterial suspension
  • Dip seeds before planting
• Microbial antagonists for root/wood rots
  • Multiply Trichoderma (and antagonists like Streptomyces)
  • Apply to nursery media / field strategies
• Insect biological control
  • Multiply and release parasitoids/predators
  • Use entomopathogenic fungi/insect pathogens when appropriate

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Researchers / Sources Featured (Named)

• Dr. Budi Tjahjono (speaker)
• Prof. Budiasuti (root rot expert; mentions development of Pekoderma—subtitles garbled)
• Prof. Widastuti (researcher on Trichoderma)
• Prof. Widya Studi (lecturer name; role unclear from subtitles)
• Mas Andre (mentioned earlier; associated with mucus/disease explanation)
• Mbak Hedia (mentioned earlier; associated with mucus/disease explanation)
• Mr. Bayok (assistant; doctorate topic on bacterial wilt in eucalyptus)