When pineapple is most vulnerable
From establishment (0 to 3 months) through canopy closure (month 10 to 12). Weed damage after canopy closure is minor because the pineapple canopy shades most weeds.How weed pressure shows in satellite data
- NDVI above phase baseline in early months (weeds add greenness) then a drop when weeds are killed or the pineapple falls behind.
- Patchy NDVI where mulch has failed and weeds are dense.
- Distinguishable from healthy pineapple by texture on high-resolution imagery.
- Difficult to separate from establishment failure without ground truth.
Field symptoms
- Weeds visible between rows and in the furrow
- Weeds emerging through torn plastic mulch
- Poor pineapple growth in weedy zones
- Mealybug and ant activity in weedy patches
- Grass and broadleaf weeds on headlands provide thrips reservoirs
- Volunteer pineapple from previous cycle
Reduce the damage by
- Plastic mulch as the primary in-row control - install carefully and repair tears immediately.
- Pre-emergence herbicides on furrows and between rows - diuron, bromacil, or ametryn (subject to registration).
- Post-emergence herbicides - glyphosate (directed away from pineapple) or fluazifop for grass. Paraquat, the traditional shielded-spray option, has been banned in Malaysia since 2020 - see Pesticide registration.
- Hand-weeding in the leaf axil and around the plant base where herbicide cannot reach.
- Cover crops on headlands - low-growing species that outcompete weeds without harboring pests.
- Manage headlands monthly - mow or spray to prevent seed set.
- Bare-ground barrier between old and new blocks reduces mealybug and ant migration.
- Do not compost weeds with mealybugs or thrips into the block; burn or remove.
Set an alert for early warning
Recommended settings for weeds on pineapple:- Mulch inspection reminder - monthly for the first 6 months, then quarterly.
- Herbicide-application reminder - schedule pre-emergence at planting and follow-up post-emergence at 3 and 6 months.
- NDVI anomaly alert - trigger on patchy low NDVI in the first 3 months (establishment failure or weed pressure).
- Headland-management reminder - monthly mowing or spraying reminder for the entire cycle.
Related
- Pineapple Diagnosis
- Mealybugs - weeds are a mealybug reservoir.
- Thrips - weeds are a thrips reservoir.
- Set up automated crop alerts