Satellite-Identified Stress — Confirmed Field Visit Required
VIGIL EARTH satellite analysis detected two distinct stressed zones within this plantation using 246 Sentinel-2 scenes from 2021–2025. NDVI dropped significantly below the 4-year baseline starting August 2025. This brief tells you exactly where to go and what to look for on your May 6 visit.
FFB Yield Impact Detected
Only FFB (Fresh Fruit Bunch) yield was reported as reduced — banana yield was unaffected. This rules out a broad field-wide issue and points directly to palm-specific crown or root stress. The most likely cause: Rhinoceros Beetle infestation in Zone 1, Ganoderma or Bud Rot under investigation in Zone 2.
Zone 1 NDVI (Aug–Oct avg)
0.31
vs. 0.83 healthy baseline
Zone 2 NDVI (Oct 2025)
0.39
vs. 0.83 healthy baseline
First Stress Signal
Aug 16
2025 — Zone 1 only
Field Area Affected
~30%
6 of 20 pixel zones flagged
Satellite Overlay
Your Field — Stress Zones Mapped
Red and orange overlays show where NDVI dropped below the 4-year healthy baseline. Numbered pins are your GPS waypoints.
ESA Copernicus Sentinel-2 · ESRI World Imagery basemap · Stress overlay: NDVI deviation Aug–Oct 2025 · 20m pixel resolution · EPSG:32644
Priority Zone · Inspection Waypoint 1
Zone 1 — North-West Corner
Strongest NDVI drop in both August and October 2025. This is your first stop.
⬤ Critical — Waypoint 1
North-West Block
📍 19.1207°N, 83.6870°E — Open in Google Maps
NDVI 0.27–0.39 · Healthy baseline: 0.83 · Appeared Aug 2025
01
-
1Inspect each palm crown for V-shaped or D-shaped frond cuts The Rhinoceros Beetle bores into the crown from the top, leaving a distinctive V or D cut on the midrib of young fronds. Look up at the top of each palm.
-
2Check the spear — the tallest unopened central frond Look for a circular borehole at the very base of the spear. The beetle tunnels down through this frond before the others. If the tip is ragged or chewed, that's a strong positive sign.
-
3Look for adult beetles at dusk or inside the crown Rhinoceros Beetle (Oryctes rhinoceros) adults are 4–5 cm, shiny black, with a horn on the head. They feed at night and hide in the crown or decaying matter during the day.
-
4Dig 30–40 cm around the trunk base and root zone Look for white C-shaped grubs (larvae, 4–6 cm). The beetle breeds in rotting organic matter — check nearby compost piles, old palm stumps, or decaying banana pseudostems from the recent harvest.
-
5Count and mark every damaged palm in this block Use paint or flagging tape. This 40m × 60m block is approximately 12–15 palms at typical spacing. Mark each one so we can track stress spread on the next satellite pass (mid-May 2026).
ⓘ This zone showed stress in both August 16 AND October 18, 2025 — two separate dips with a partial recovery in September. The double-wave pattern with partial recovery in between is characteristic of insect attack rather than a root disease (which would show continuous decline).
Secondary Zone · Inspection Waypoint 2
Zone 2 — East Boundary Strip
Stress appeared only in October 2025. Investigate Ganoderma fungus and drainage as primary causes.
⬤ Moderate — Waypoint 2
East Boundary Strip
📍 19.1196°N, 83.6883°E — Open in Google Maps
NDVI 0.34–0.43 · Healthy baseline: 0.83 · Appeared Oct 2025 only
02
-
1Check trunk base and root zone for Ganoderma bracket fungi Look for orange-brown shelf-shaped mushrooms (conks) growing from the trunk base or exposed roots. Even small ones — 5–10 cm — are significant. Photograph immediately if found. Ganoderma BSR is fatal and untreatable once confirmed.
-
2Pull the central spear and check for Bud Rot Gently grasp the spear (tallest unopened frond) and pull upward. If it slides out easily or smells putrid, that is Bud Rot — a fungal disease triggered by wet monsoon conditions. The rotting typically starts at the base of the spear.
-
3Check if stressed palms align with a drainage channel or fence Zone 2 runs along the eastern boundary of the field. If all affected palms are along a ditch, channel, or low-lying area, waterlogging is the primary cause — not disease. Note if the soil feels consistently wet or compacted vs. the field interior.
-
4Compare FFB bunch size and maturity to healthy palms Stand beside a stressed palm and a healthy palm (from the field centre). Compare bunch size, number of spikelets, and whether the fruit has set. This gives us a field-level yield correlation to pair with the satellite data.
-
5Check frond yellowing pattern — tip inward or outward? Yellowing from the frond tip inward = nutrient deficiency (potassium most likely). Yellowing from the midrib outward = root/vascular issue (Ganoderma or waterlogging). The direction tells us which system is failing.
ⓘ Zone 2 stress appeared only in October 2025 and not in August — suggesting a newer or slower-developing issue. The timing (post-monsoon onset) and boundary-edge location makes waterlogging and Ganoderma the primary candidates. The partial September recovery in Zone 1 did not appear here.
Differential Diagnosis
What the Satellite Data Suggests
Based on NDVI/EVI/NDRE pattern, timing, and the field context you provided (FFB-only drop, banana unaffected, recent harvest).
Most Likely — Zone 1
Rhinoceros Beetle (Oryctes rhinoceros) 75% confidence
Double-wave NDVI dip (Aug + Oct) with partial Sep recovery is the classic beetle damage pattern. FFB-only yield loss with healthy banana rules out soil or root disease. The recent banana harvest left large amounts of decomposing pseudostem — ideal beetle breeding ground.
All Candidates Evaluated
| Condition | Zone | Probability | Key Evidence For | Key Evidence Against |
|---|---|---|---|---|
| Rhinoceros Beetle | Zone 1 | 75% | Double-wave dip, partial recovery, FFB-only loss, post-harvest debris | Cannot confirm without physical crown inspection |
| Ganoderma BSR | Zone 2 | 55% | Oct-only onset, east boundary strip, post-monsoon timing | Ganoderma shows continuous decline — no recovery expected |
| Bud Rot (Phytophthora) | Zone 2 | 30% | Wet monsoon 2025, post-monsoon onset timing | Usually spreads rapidly in cluster — single strip unusual |
| Waterlogging / Drainage | Zone 2 | 35% | East boundary alignment, oct-only, recoverable if addressed | Drainage issues usually affect lower-lying field centre too |
| Nitrogen Deficiency | Both | 10% | Intercropping competition from banana roots | Would show gradual uniform decline, not two distinct zones |
Documentation Guide
What to Photograph on May 6
Send these photos back and we can update the diagnosis before the next satellite pass.
Palm crown from below (looking up)
Show the young fronds at the top. Capture any V-cuts, D-cuts, or holes at the spear base. Take one from each damaged palm.
Trunk base and root zone
Ground level, showing the trunk base and soil surface. Critical for ruling out Ganoderma bracket fungi — even small ones visible at 30 cm.
Frond yellowing pattern
Close-up of a yellowing frond — show whether colour starts at tip or at midrib. This single photo narrows the diagnosis significantly.
FFB bunch — stressed vs. healthy palm
Side by side if possible. Show bunch size, fruit set, and maturity stage. This lets us correlate satellite anomaly to actual yield loss per palm.
Any beetles, grubs, or insects found
If you dig and find white C-shaped grubs, or see adult beetles, photograph against a hand or coin for scale. Crucial for confirming Rhinoceros Beetle vs. other pests.
Wide shot of each zone
Stand at the GPS pin and take a wide-angle photo of the surrounding palms. Shows density of damage and helps us calibrate how many palms are in the satellite pixel.
What Happens After Your Visit
Next Steps Timeline
Based on what you find, here is the response pathway.
May 2, 2026
Completed
Satellite Analysis — Stress Zones Identified
246 Sentinel-2 scenes processed. Two distinct anomaly zones confirmed. Double-wave stress pattern identified. This field inspection brief prepared.
May 6, 2026
Your Visit
Physical Field Inspection — Confirm or Eliminate Rhinoceros Beetle Pending
Visit Zone 1 and Zone 2 using GPS waypoints in this brief. Document crown damage, root zone, and trunk base. Send photos for updated diagnosis.
May 7–8, 2026
Immediate Response (if beetle confirmed)
Treatment: Naphthalene balls + crown injection If confirmed
Place 2–3 naphthalene balls in the crown funnel of each affected palm (standard Rhinoceros Beetle control). Remove and burn all decomposing banana pseudostems within 50m — that is likely the breeding site.
May 7–8, 2026
Immediate Response (if Ganoderma confirmed)
Isolate infected palms — remove and destroy If confirmed
No curative treatment exists for Ganoderma BSR. Infected palms must be felled and the trunk shredded (not piled). Apply fungicide to surrounding soil. Contact a certified palm pathologist for soil testing before replanting.
Mid-May 2026
Next Satellite Pass
Follow-up Sentinel-2 analysis — track response Scheduled
VIGIL EARTH will process the next available cloud-free scene over your field. We will compare NDVI in the flagged zones against your treatment date to confirm whether vegetation is recovering or declining further.
June 2026
Updated Report
Treatment Efficacy Report — satellite vs. field confirmed
Full updated report comparing pre-treatment and post-treatment NDVI across all zones. Will include yield projection adjustment if recovery trend is confirmed by satellite.
Action Checklist
Before You Go on May 6
Do This Now
Save GPS waypoints in your phone
Zone 1: 19.1207, 83.6870 — Zone 2: 19.1196, 83.6883. Open both in Google Maps and save them as favourites. Both zones are within walking distance of each other (under 200m apart).
Bring on May 6
Tools for the field inspection
A small spade or digging stick (for root zone inspection), a long stick or pole (to probe the crown from below), and your phone camera. Gloves recommended if handling soil around beetle larvae.
After the Visit
Send photos to VIGIL EARTH for updated diagnosis
Share the photos from the documentation guide above. With physical confirmation, we can narrow the diagnosis to a single cause with high confidence and prepare a targeted treatment plan for the next growing season.
Optional — Longer Term
Remove decomposing banana pseudostems from Zone 1 area
The recent banana harvest left organic debris near Zone 1. This is the prime breeding habitat for Rhinoceros Beetle. Even before field confirmation, clearing this material reduces pest pressure immediately.
After Your May 6 Visit
Share what you find and we update the satellite analysis with ground truth. Here is what helps most:
- Photos of frond cuts, trunk base, any grubs or fungi found
- How many palms in Zone 1 show visible crown damage
- Whether Zone 2 palms are near a drainage channel or low-lying area
- Any smell of rot when you pull the central spear
With this information, VIGIL EARTH can issue a treatment confidence update within 48 hours and schedule the next satellite monitoring pass for mid-May.