Integrated Pest Management – Quarantine Control II

Historical Impact of Introduced Pests & Pathogens

Middle of 19th century introductions from America devastated European viticulture
- Powdery mildew (Uncinula necator)
- Grape phylloxera
- Downy mildew (Plasmopara viticola)
Chestnut blight (Endothia parasitica) arrived in the USA on Oriental nursery stock in 1906
- Virtually eliminated the American chestnut as a forest tree
- Caused extensive economic and ecological losses
Coffee leaf rust (Hemileia vastatrix) in Sri Lanka led to replacement of coffee with tea as a plantation crop
Coconut leaf miner (Promecotheca cumingi) destroyed about 20000 ha of coconut plantations in the late 1960\text{s}

Plant introductions include:
- New crops or varieties for diversification
- Germplasm of primitive landraces, wild/weedy relatives
Traits sought from centres of origin/diversity
- Resistance to pests/pathogens, high yield, early maturity, tolerance to cold/drought/salinity, improved oil/protein content, etc.
Dual mandate of quarantine services
- Prevent entry of hazardous organisms
- Facilitate entry of valuable genetic resources “in a healthy state”
Operational expectations for quarantine officials
- Provide safeguards and fast processing once material arrives at the station
- Never circumvent quarantine even if it delays or rejects material

Plant vs. animal quarantine share objectives but differ in biology, production systems, trade logistics → require distinct procedures
Regulated plant materials may include seed, straw, cereal hulls, timber, fruit, vegetables, cut flowers, fibres, gums, spices
Regulated animal materials may include live animals, semen, embryos, meats (fresh/frozen/canned), milk products, hides, biological reagents (proteins, hormones, sera)

Core goal: detect any pest/pathogen on introduced material with zero tolerance
Two broad classes of tests
- Generalized (broad-spectrum)
- Specialized (organism-specific)

Visual inspection of dry seed (naked eye & low-power microscope)
Examination under UV/NUV light → fluorescence of infected seed coats
Seed-wash microscopy → rusts, smuts, downy mildews, etc.
Incubation methods (moist blotter or agar) for ≈1 week under alternating light/dark
Seedling-symptom test & grow-out test → show symptoms from fungi, bacteria, viruses
- Grow-out is primary screen for viruses; must be paired with indexing on indicator plants & serology because some viruses remain symptomless

Insects
- X-ray radiography: detects hidden infestations
- Seed transparency test: reveals internal feeders; allows extraction & identification
Nematodes
- Soak soil/plant debris; extract with nematological sieves or tissue paper
Fungi, bacteria, viruses
- Serology (e.g., ELISA) → sensitive, rapid identification
- Phage-plaque technique → distinguishes bacterial strains
- Indicator plants → differentiate fungal/bacterial races & virus strains
- Modified incubation media
- Deep-freezing blotter & 2,4\text{-D} blotter for Phoma lingam (black-leg)
- Potato-dextrose-oxgall agar for Septoria nodorum in wheat
- PCNB agar selectively recovers Fusarium spp. in cereals
Lab methods generally adequate for insects, mites, nematodes, most fungi, certain bacteria

Quarantine tolerance = 0 → no residual inoculum permitted
Available interventions
- Fumigation
- Heat (hot water/hot air) treatment
- Chemical treatments (seed dips, disinfectants, systemic pesticides)
- Tissue culture (meristem/embryo culture)

Atmosphere or reduced-pressure fumigation effective for insects & mites
Common fumigants: methyl bromide, HCN, phosphine, EDCT (ethylene dichloride + carbon tetrachloride)

Nematodes
- Flower bulbs: 44\,^{\circ}C for 240 min
- Chrysanthemum: 48\,^{\circ}C for 25 min
- Potato tubers: 45\,^{\circ}C for 5 min
Insects & mites
- Narcissus bulbs: 44\,^{\circ}C for 180 min
- Strawberry runners: 46\,^{\circ}C for 10 min
Viruses
- Grapevine: 45\,^{\circ}C for 120–180 min
- Sugarcane setts: 50\,^{\circ}C for 120 min
- Potato tubers: 50\,^{\circ}C for 17 min
Fungi
- Celery seed: 50\,^{\circ}C for 25 min
- Wheat seed: 52–54\,^{\circ}C for 10 min

Availability of trained personnel & diagnostic capacity
Detection technique effectiveness
Feasible treatments at entry
Detailed knowledge of pest life cycle, races/strains
Modes of transmission & factors aiding establishment/spread
Existing safeguards: manpower, chemicals, equipment, containment & eradication plans
Adequacy of survey & surveillance programmes post-entry

Consortium of plant quarantine stations → harmonise protocols, data sharing
Central seed-health testing laboratories → reference diagnostics
Third-country intermediate quarantine → stepwise screening in climates unfavourable to pest establishment
Biogeographical regions → region-specific pest lists & cooperative control

Continuous inflow of valuable germplasm is essential for sustainable agricultural growth
Simultaneous protection against exotic pests, pathogens, weeds is equally critical
Effective quarantine must be science-based & driven solely by pest-introduction risk

Plant pests/pathogens cause heavy losses in field & storage
Quarantine regulations (e.g., Malaysia & other nations) govern movement of plants/products to prevent entry of harmful exotics
Quarantine only effective against pests without natural long-distance transport
Complementary role of national services & coordinated cooperation enables safe germplasm flow

Malaysian Quarantine & Inspection Services (MAQIS): http://www.maqis.gov.my/
Muthaiyan, M. C. (2009) Principles and Practices of Plant Quarantine.
Paroda, R. S. & Arora, R. K. (1991) Conservation and Management: Concepts and Approaches.
Videos
- “Imported Agriculture Products” — https://youtu.be/PEzf7XodY8g
- Bureau of Plant Industry – National Plant Quarantine Services Division — https://youtu.be/VZDYJGfCQVw
- “Phytosanitary and Food Safety Certification of Pineapple” — https://youtu.be/WB7GGBEWyTc