> ## Documentation Index
> Fetch the complete documentation index at: https://badixth-dc85e378.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Diagnose and Respond to Weeds in Pineapple

> Identify weed pressure in pineapple from open ground between plants, patchy establishment, and mealybug and nematode reservoirs, and reduce damage with plastic mulch, pre- and post-emergence herbicides, and cover crops.

Weeds cost pineapple yield through direct competition (water, nutrients, light) and as reservoirs for **mealybugs**, **thrips**, and **nematodes**. Pineapple's slow canopy development (10 to 12 months to close) makes weed control critical for the entire first year of the cycle. Plastic mulch handles most of the in-row problem; the between-row and headland problem is where the yield loss and vector risk sit.

**Regional priority:** Universal. Highest on newly-cleared land, ratoon blocks, and any block with damaged mulch.

## 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](/snippets/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

<Tip>
  Weed monitoring is best done with scheduled scouting and mulch inspection. Satellite alerts help detect early canopy failure that may be weed competition.
</Tip>

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](/guides/Crop/Pineapple/pineapple-diagnosis)
* [Mealybugs](/guides/Crop/Pineapple/biotic/insects/mealybugs) - weeds are a mealybug reservoir.
* [Thrips](/guides/Crop/Pineapple/biotic/insects/thrips) - weeds are a thrips reservoir.
* [Set up automated crop alerts](/guides/alerts-notifications)