> ## 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.
# Pineapple Diagnosis: Decide What a Field Change Means and What to Do
> The starting point for interpreting pineapple field changes across a 14 to 24 month cycle. Covers all three pillars: abiotic stress, nutrient disorders, and biotic stress, plus a scout-first decision tree keyed to leaf whorl, heart, and fruit symptoms.
Pineapple is a 14 to 24 month crop planted at 50,000 to 70,000 plants per hectare on plastic mulch. Diagnosis works at three scales at once: whole block, planting bed, and individual plant. Use this guide to move from a field observation or a satellite alert to a specific cause and a specific action.
For the standard census and inspection sequence a scout should follow on the ground, see [Field Walk Protocol](/guides/Crop/Pineapple/field-walk-protocol).
## The three pillars
Water deficit, waterlogging, sunburn, chilling, wind, and salinity on BRIS. Slow to moderate, block-scale, weather and drainage driven.
N, K, Mg, Fe, Zn, Ca, B. Foliar sprays are the primary correction because pineapple absorbs most nutrients through the leaf axil.
Diseases, insect pests, nematodes, and weeds. Individual-plant and cluster-scale. Ground confirmation essential.
## Scout-first decision tree
Use what you see first to pick the pillar. The scout looks at four things on each plant, in this order.
### 1. Block-level pattern
| What you see across the block | Likely pillar |
| ---------------------------------------------------------- | ------------------------------------------------------------------------------------------------- |
| Whole block uniformly off, matches weather or soil map | **Abiotic** or block-wide nutrient |
| Gradient across the block following topography or drainage | **Abiotic** (waterlogging, drought) or soil-linked nutrient |
| Wet spots with collapsed plants after heavy rain | **Biotic** - [Heart rot / Phytophthora](/guides/Crop/Pineapple/biotic/diseases/heart-rot) |
| Circular expanding patches of wilted, red-yellow plants | **Biotic** - [Mealybug wilt](/guides/Crop/Pineapple/biotic/diseases/mealybug-wilt) |
| Slow diffuse decline over months, no clear pattern | **Biotic** - [Nematodes](/guides/Crop/Pineapple/biotic/diseases/nematodes) or chronic nutrient |
| Scattered dead plants along headlands, machinery tracks | **Biotic** - [Fusariosis](/guides/Crop/Pineapple/biotic/diseases/fusariosis) or mechanical injury |
| Bleached, upright leaves on sun-exposed rows | **Abiotic** - [Sunburn](/guides/Crop/Pineapple/abiotic/sunburn) |
### 2. Leaf whorl color and position (nutrient and disease decision)
Pineapple leaves are numbered by the D-leaf convention: the tallest, most-erect fully-expanded leaf is the **D-leaf** (roughly the 3rd or 4th leaf from the center) and is the reference for nutrient sampling.
| What you see | Where on the plant | Likely cause |
| -------------------------------------------------------- | ----------------------- | --------------------------------------------------------------------------- |
| Whole rosette pale green | All leaves | [Nitrogen](/guides/Crop/Pineapple/nutrient/nitrogen) |
| Yellow-orange older leaves, tips die back | Lower whorl | [Potassium](/guides/Crop/Pineapple/nutrient/potassium) |
| Yellow between veins on older leaves, red-purple margins | Lower whorl | [Magnesium](/guides/Crop/Pineapple/nutrient/magnesium) |
| Yellow young leaves, green veins | Center whorl / D-leaves | [Iron](/guides/Crop/Pineapple/nutrient/iron) (chlorosis) |
| Small, pale, distorted young leaves | Center whorl | [Zinc](/guides/Crop/Pineapple/nutrient/zinc) (crookneck) |
| Cracked, corky, or split young leaves and fruit | Center whorl + fruit | [Boron](/guides/Crop/Pineapple/nutrient/boron) |
| Red-brown discoloration on leaf tips of older leaves | Lower whorl | [Calcium](/guides/Crop/Pineapple/nutrient/calcium) (edge burn) or salinity |
| Yellow tips with pink flush on older leaves | Lower whorl | Early [Mealybug wilt](/guides/Crop/Pineapple/biotic/diseases/mealybug-wilt) |
### 3. Heart, base, and roots (disease decision tree)
| What you see | Likely cause |
| -------------------------------------------------------- | ---------------------------------------------------------------------------------------------- |
| Center whorl leaves pull out with a foul smell | [Heart rot](/guides/Crop/Pineapple/biotic/diseases/heart-rot) (Phytophthora) |
| Whole plant tips over, black rotted base | [Root rot](/guides/Crop/Pineapple/biotic/diseases/root-rot) (Phytophthora cinnamomi) |
| Basal white rot with pink or brown stain | [Fusariosis](/guides/Crop/Pineapple/biotic/diseases/fusariosis) |
| Water-soaked black lesions on harvested fruit | [Black rot](/guides/Crop/Pineapple/biotic/diseases/black-rot) (Chalara / Thielaviopsis) |
| Waxy white or grey insects at leaf base, sticky honeydew | [Mealybugs](/guides/Crop/Pineapple/biotic/insects/mealybugs) |
| Ants trailing along the plant base | Mealybug or scale tending |
| Stunted, thick, twisted roots | [Nematodes](/guides/Crop/Pineapple/biotic/diseases/nematodes) (root-knot, reniform, or lesion) |
| White centipede-like arthropods in the soil at planting | [Symphylids](/guides/Crop/Pineapple/biotic/insects/symphylids) |
### 4. Fruit and crown (yield-critical decision tree)
| What you see | Likely cause |
| ------------------------------------- | -------------------------------------------------------------------------------------------------------------------------- |
| Small, misshapen, or knobby fruit | [Boron](/guides/Crop/Pineapple/nutrient/boron), [Calcium](/guides/Crop/Pineapple/nutrient/calcium), or thrips at induction |
| Sunburned, bleached fruit shoulders | [Sunburn](/guides/Crop/Pineapple/abiotic/sunburn) (fruit exposed) |
| Multiple crowns or fasciated crown | Genetic / temperature at forcing |
| Silver flecking on leaves and fruit | [Thrips](/guides/Crop/Pineapple/biotic/insects/thrips) |
| Fine yellow stippling on leaves | [Mites](/guides/Crop/Pineapple/biotic/insects/mites) |
| Internal browning of ripe fruit flesh | Chilling injury during storage or field cold snap |
| Sap-oozing fruit with tunnel | Fruit borer / fruitlet core rot |
| Small tan bumps on lower leaves | [Scale](/guides/Crop/Pineapple/biotic/insects/scale) |
## Growth-phase vulnerability
Different stresses matter at different phases. Use this alongside the pattern tables.
| Phase | Months after planting | What matters most |
| ----------------- | --------------------- | ------------------------------------------------------------------------------- |
| Establishment | 0 – 3 | Sucker rot, symphylids, weeds, drought at rooting |
| Early vegetative | 3 – 8 | N, weeds, mealybugs, mites, mealybug wilt onset |
| Late vegetative | 8 – 12 | K, Mg, Fe, heart rot after heavy rain, nematode decline |
| Forcing | 12 – 14 | Cold at forcing (multiple crowns), Ca and B before differentiation |
| Fruit development | 14 – 18 | Sunburn, thrips, fruit borers, mealybug wilt spread, Ca and K for fruit quality |
| Ripening | 18 – 22 | Sunburn, black rot at harvest, rodent and bird damage, sugar accumulation |
## How satellites contribute
Pineapple imagery is trickier than paddy or oil palm because of low canopy height, plastic mulch, and CAM physiology. Match the tool to the question.
| Scale | Best for | Typical alert |
| ---------------- | --------------------------------------------------------- | ----------------------------------------------- |
| Block / canopy | Slow abiotic and nutrient decline, block-wide stress | NDVI or NDRE monthly trend below phase baseline |
| Bed / cluster | Spreading disease foci (mealybug wilt, heart rot pockets) | Localized NDVI drop expanding month to month |
| Individual plant | Single dead plants, gap counting | Very-high-resolution or drone imagery |
Pineapple's CAM physiology delays visible NDVI response to drought by 2 to 4 weeks. Use **NDWI** and **CWSI** rather than NDVI as the early water-stress signal. NDVI is a lagging indicator for pineapple water stress.
## Decision flow
Uniform, gradient, wet-spot cluster, or expanding focus? Use the block-level table to pick the pillar before you walk in.
Follow the [Field Walk Protocol](/guides/Crop/Pineapple/field-walk-protocol). Check whorl color, heart and base, roots, and fruit in that order.
Use the leaf, heart, and fruit tables above to move from symptom to page.
Apply the recommended action, record the plant or block, and use the [Alerts](/guides/alerts-notifications) page to configure a follow-up so the same issue is flagged earlier next time.
## Related
* [Healthy NDVI ranges for pineapple across planting environments](/guides/Crop/Pineapple/pineapple-ecosystems) - phase baselines to compare against.
* [Field Walk Protocol](/guides/Crop/Pineapple/field-walk-protocol) - the standard scout inspection sequence.
* [Set up automated crop alerts](/guides/alerts-notifications) - configure the triggers that surface these stresses.
* [Analyze crop performance across a full season](/guides/seasonal-analysis) - the right tool for slow pineapple decline.
This diagnosis covers the three major stress groups plus a scout-first decision tree. Rare stresses (herbicide phytotoxicity, mineral deposits, physiological disorders like internal browning and translucency) can be added as short reference pages later.