When pineapple is most vulnerable
Most damaging from late vegetative (month 8) through fruit development (month 18). Water deficit at forcing causes small, misshapen fruit; water deficit during fruit filling reduces fruit weight and sugar. Establishment drought (first 3 months) causes patchy stands and slip failure.How drought shows in satellite data
- NDWI drops first, typically 2 to 4 weeks before NDVI moves. Use NDWI as the primary drought signal on pineapple.
- CWSI rises as canopy temperature climbs above air temperature.
- NDVI decline is delayed and shallow because CAM plants keep leaves green under moderate stress. A visible NDVI drop means severe or prolonged deficit.
- Pattern is typically block-wide, matches rainfall records, and is more severe on sandy or shallow soils.
Field symptoms
- Leaf tip die-back on older leaves, progressing inward
- Reduced D-leaf length compared with same-age plants on irrigated blocks
- Red-purple flush on exposed leaves in prolonged dry weather
- Delayed response to forcing chemicals; uneven flowering
- Small, tapered fruit with poor shoulder fill
- Sunburn risk rises as leaf cover reduces
- Roots stay shallow and few new feeder roots form
Reduce the damage by
- Plastic mulch on all beds - the single largest water conservation tool on pineapple.
- Drip irrigation under the mulch where infrastructure allows; broadcast overhead irrigation is inefficient on plastic mulch.
- Time forcing to a wet-season window so fruit development coincides with reliable rainfall.
- Increase K in late vegetative fertilization - K improves stomatal control and drought tolerance.
- Avoid N top-dressing during dry spells - N without water pushes soft growth that burns.
- Delay planting on BRIS or shallow soils if the season starts dry.
- Windbreaks on exposed BRIS sites reduce leaf transpiration.
Set an alert for early warning
Recommended settings for drought on pineapple:- NDWI threshold alert - trigger when block NDWI drops 0.10 or more below the phase baseline for 2 consecutive passes.
- Weather alert - 14 or more consecutive days below 50% of long-term rainfall during months 8 to 18.
- CWSI trend alert - trigger when the block’s CWSI rises above 0.4 on any pass during fruit development.
Related
- Pineapple Diagnosis
- Healthy NDVI ranges for pineapple - phase baselines to compare against.
- Sunburn - drought raises sunburn risk.
- Set up automated crop alerts