Integrated Pest Management
Control pests by design first; spray only when the numbers say you should.
6 min read
Updated 3 October 2026
Reference Library
IPM integrated pest management scouting thresholds spray programme resistance
Integrated pest management (IPM) is not "spraying less". It is a decision system: prevent, monitor, decide, act, verify . Applied properly it costs less than calendar spraying and produces a more stable crop.
The five components#
Component What it means in a banana block 1. Prevention Clean planting material, sanitation, resistant clones, windbreak, balanced nutrition, hygiene between blocks 2. Monitoring Scheduled scouting, traps, weather data, leaf-area assessment 3. Thresholds Pre-agreed numbers that trigger action — no threshold, no spray 4. Control Cultural and biological first; targeted chemical last, rotated 5. Verification Re-scout after action; record results; adjust next season
Prevention: the controls that cost nothing per season#
Monitoring: what to scout and when#
What How Frequency Where Leaf disease (Sigatoka) Count affected leaves / estimate % affected leaf area on 20 plants Weekly in humid seasonRandom or transect through the block Aphids (incl. BBTV vector) Inspect the underside of young leaves, emerging suckers Monthly; weekly in an outbreak 5 plants per 100 Weevil Inspect corm collars of cut stumps; nut-shell traps; hand counts at dusk Monthly Border rows first Nematodes Soil and root samples, 4–5 sites per block 1–2× per year, or if stunting Compare zones Thrips Inspect emerging bunch, bracts, hands Weekly after bunch emergence 20 bunches Fruit fly Protein bait traps or MQL traps Weekly counts Block margins and nearby forest Mites / mealybug Inspect underside of leaves and crown Monthly Symptomatic plants first Fruit damage at packout Grade-out records Every shipment Feeds back to the field
Trap guidance#
Trap Target Placement Use Yellow sticky trap Aphids, whitefly, thrips, leafhoppers At canopy height, 4–6 per hectare Monitoring only Pheromone / nut-shell trap Banana weevil Base of cut stumps, shaded Counts inform corm damage assessment Protein bait / McPhail trap Fruit fly Border trees, 1–2 per ha Weekly counts Black light / funnel trap Moths (leaf rollers, borer moths) Near canopy Monitoring
Thresholds#
Thresholds are local — set them with your extension adviser, then write them on the wall of the store.
Pest / disease Typical action trigger Comment Black Sigatoka 1–2% affected leaf area, or first lesions on the 3rd–4th youngest leaves Early action preserves the upper canopy — the leaves that matter most Yellow Sigatoka Lesions on lower third of leaf Slower disease; lower spray frequency Aphids (BBTV area) Any infected plant found → rogue immediatelyZero tolerance in a bunchy top area Weevil > 10% corm damage at harvest, or 0.5–1 adult/trap/night Post-harvest assessment guides next season Nematodes > 1,000–2,000 propagules per 200 g soil, or visible stunting Interpret with symptoms and root damage Fruit fly 5–10 flies per trap per week Bait and MQL programmes before threshold Thrips Scarring observed on 5%+ of bunches Protect at bunch emergence Mealybug / scale Visible colonies on 10%+ of plants Usually a natural-enemy imbalance
★ The leaf-area threshold that matters most
Keep the canopy green. Spraying decisions should be driven by affected leaf area on the upper 5 leaves , not by calendar dates. A programme that protects the youngest 6 leaves through flowering and filling delivers the yield; a calendar programme often protects leaves that were going to be removed anyway.
Control tactics in order of preference#
1. Cultural and mechanical#
Resistant or tolerant clone selection (e.g. Sigatoka-resistant FHIA/NARITA/goldfinger-type selections). Optimal spacing for airflow; correct desuckering so the canopy is not a humid thicket. Sanitation — destroy infected tissue. Windbreak to reduce leaf tearing (tears are entry points). Balanced nutrition (no excess N). Weed control — removes aphid reservoirs and alternative hosts. Mulch — reduces soil splash of spores onto leaves. Propping and staking to reduce mechanical damage. 2. Biological and conservation#
Conserve natural enemies: parasitoids, predators, spiders, lacewings. Avoid broad-spectrum sprays that destroy them. Entomopathogenic nematodes and Beauveria bassiana for weevil — used in organic and low-residue systems.Trichoderma Protein bait stations selectively target fruit fly with far less impact than broadcast sprays.Bird and bat habitat at field margins for insect control. 3. Physical and mechanical#
Pupation traps and soil covering around stumps to interrupt the weevil life cycle. Hot-water treatment of planting material. Screening and hygiene in the packhouse. Hand-picking of egg masses and larvae where labour is cheaper than spray. 4. Chemical — last, and targeted#
When thresholds are crossed:
Principle Practice Right product Match the identified pest or pathogen — confirm diagnosis first Right rate Label rate only; never "double up" because it "seems worse" Right timing Target the vulnerable life stage; for Sigatoka, protect young leaves Right coverage Banana canopies need volume and droplet size — poor coverage is wasted money Rotation Rotate FRAC (fungicide) and IRAC (insecticide) mode-of-action groups to delay resistance Records Product, batch, rate, area, operator, weather, time — required for audits and traceability Pre-harvest interval Observe strictly; residues are tested on the fruit the buyer sells Personal protective equipment Mandatory; see Safety and sustainability Buffer zones Protect water bodies, neighbouring crops, hives and homes
Resistance management in practice#
Black Sigatoka programmes in humid tropics historically used the same fungicide class repeatedly — resistance (particularly to DMI and QoI chemistry) followed. The rule:
Never use the same FRAC group two applications running. Rotate at least 3 different FRAC groups across a season. Mix a multisite protectant with a systemic where labels allow. Scout after every application; if control is poor, you likely have resistance — change group, not rate. Spray application quality#
Factor Target Water volume (backpack) 300–600 L/ha depending on canopy Water volume (airblast/tractor) 400–800 L/ha Droplet size Medium (200–400 µm) for canopy coverage without drift Time of day Early morning (before heat, after dew dries) or evening Wind < 10 km/h; no application in strong wind or inversion Nozzle wear Replace on a schedule — worn nozzles apply under-rate and wrong spectrum Adjuvant Where the label allows it; improves rainfastness and spread
Documentation#
Keep a simple spray diary :
Date Block Pest/disease observed Threshold reached? Product + FRAC group Rate Volume Operator Weather Re-scout date Outcome
This single record supports certification, resistance management, residue compliance and next year's decisions.
IPM by season#
Season phase Focus Pre-plant Clean material, soil health, resistant clone, sanitation Establishment Cutworm, snail, weevil; weed control; stand audit Vegetative Aphids, Sigatoka onset, nematodes; balanced N Flowering Leaf protection is the priority ; thrips at bunch emergenceFilling Sigatoka upper canopy; fruit fly build-up; propping Harvest Crown-rot hygiene; fruit fly trapping; record grade-out Post-harvest Destroy stumps, desucker, assess corm damage, plan next round
Next steps#