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Disease guide

Know the enemy before you book the aircraft.

Every disease below is tagged honestly. Drone-led means aerial spraying is the primary control. Drone-assisted means the aircraft is one part of an integrated plan. Not a spray problem means exactly that — and we would rather lose a booking than spray something spraying cannot cure.

DRONE-LED DRONE-ASSISTED NOT A SPRAY PROBLEM
Arecanut · ಅಡಿಕೆ

Arecanut diseases.

Koleroga / Mahali — fruit rot DRONE-LED MONSOON

Phytophthora meadii

The disease that defines the arecanut monsoon in the Malnad and coastal belts. Tender nuts rot, blacken and drop in wet spells; unmanaged outbreaks can take half the crop or all of it. Spread is by rain splash and wind-driven spores, which is why timing beats chemistry.

Signs
Water-soaked patches on tender nuts, dark rot, heavy nut shedding under the palm, white fungal coating in humid weather.
Drone role
Prophylactic 1% Bordeaux mixture (or approved copper fungicide) applied to bunches before monsoon onset, repeated per rainfall intensity. Aerial application solves the problem that created the disease's persistence: nobody left to climb the trees in the rain.
Window
First round before monsoon break (May–June); repeat rounds through July–August in prolonged wet spells.

Bud rot DRONE-ASSISTED MONSOON

Phytophthora spp.

Infection of the growing spindle. Because the palm has a single growing point, an untreated bud rot is a dead palm.

Signs
Yellowing of the spindle leaf, rot at the crown with foul smell, spindle pulls out easily.
Drone role
Crown-directed protective spraying across the block during the koleroga rounds reduces new infections. Palms already infected need individual crown cleaning and paste treatment on the ground — spraying alone will not save them.

Leaf spot & inflorescence dieback DRONE-LED

Colletotrichum gloeosporioides and allied fungi

Anthracnose leaf spots and drying of inflorescences reduce nut set quietly, season after season. Responds well to timed fungicide rounds, and canopy-level application reaches the flowering zone no ground lance can.

Signs
Brown-black spots with yellow halos on leaves; inflorescence rachillae drying from the tip; poor nut set.
Drone role
Approved fungicide rounds at flowering and post-monsoon, combined in flight plans with nutrition sprays where deficiency is also present.

Yellow Leaf Disease (YLD) NOT A SPRAY PROBLEM

Phytoplasma-associated

The slow yellowing that haunts parts of the Malnad and Kasaragod belts. There is no chemical cure for a phytoplasma, and anyone selling you a "YLD spray" is selling you the monsoon. What aerial work can do is support palm vigour with foliar nutrition and keep secondary fungal problems off already-weakened palms — honest palliative care, clearly described as such.

Anabe roga — foot rot NOT A SPRAY PROBLEM

Ganoderma lucidum

A soil-borne root disease. Management is at the root zone — drenching, isolation trenches, sanitation — not the canopy. We will map affected zones from the air during surveys, but we will not sell you a canopy spray for a root fungus.

Coconut · തെങ്ങ് · தென்னை

Coconut diseases & pests.

Rugose spiraling whitefly DRONE-ASSISTED

Aleurodicus rugioperculatus

The invasive whitefly that swept through South Indian coconut after arriving in 2016 — sooty mould, sticky fronds, stressed palms. Here is the honest version: the long-term fix is the parasitoid Encarsia guadeloupae, and reckless insecticide blanketing kills your best ally.

Signs
White spirals on leaf undersides, waxy flocculence, black sooty mould over fronds and undergrowth.
Drone role
High-volume water washing flights to strip sooty mould and honeydew, neem-based and biorational applications where infestations are severe, and starch-solution sprays per university advisories — all scheduled to conserve parasitoid activity, not erase it.

Bud rot DRONE-LED MONSOON

Phytophthora palmivora

The same killer logic as arecanut: one growing point, no second chances. Wet, crowded gardens in heavy-rainfall belts are most at risk.

Signs
Spindle yellowing and wilting, rotting heart tissue, crown collapse in advanced cases.
Drone role
Prophylactic crown-zone fungicide rounds ahead of and during the monsoon across whole gardens — the application height that made this treatment impractical is precisely what drones remove.

Eriophyid mite DRONE-ASSISTED

Aceria guerreronis

The microscopic mite behind scarred, undersized, cracked nuts. It lives under the perianth of young buttons — a target you cannot hit from the ground on a 70-foot palm.

Signs
Triangular pale patches below the perianth on young nuts, turning to brown corky scars; distorted, shrunken nuts.
Drone role
Button-zone application of approved acaricides/botanicals (neem-garlic formulations per advisories), sequenced with root feeding done on the ground. Integrated, or it fails.

Grey leaf blight & leaf rot DRONE-LED

Pestalotiopsis palmarum; leaf rot complex

Frond diseases that sap photosynthesis, hitting hardest where palms are already stressed — including root-wilt gardens in Kerala. Straightforward canopy fungicide work, well suited to aerial rounds.

Root wilt disease (Kerala wilt) NOT A SPRAY PROBLEM

Phytoplasma-associated

Endemic to central-south Kerala. No cure exists. Good management — nutrition, leaf rot control, mite control, tolerant varieties for replanting — keeps affected palms productive for years. We will fly the parts of that plan that belong in the air and name the parts that do not.

Stem bleeding & rhinoceros beetle GROUND-FIRST PROBLEMS

Thielaviopsis paradoxa; Oryctes rhinoceros

Stem bleeding is a trunk wound disease treated by scraping and wound dressing. Rhinoceros beetle management centres on breeding-site hygiene, leaf-axil treatment and pheromone traps. Aerial spraying is not the tool — and we will tell you so.

Oil palm

Oil palm problems.

Leaf-eating caterpillars DRONE-LED

Slug caterpillars, bagworms and allied defoliators

Defoliation outbreaks can strip fronds across a block in weeks, cutting bunch weight for the next two years. Oil palm's uniform canopy at moderate height makes it one of the best drone-spraying targets in the plantation world — the crop where aerial application first proved itself at scale in Malaysia and Indonesia.

Drone role
Rapid block-wide application of approved insecticides or Bt-based biologicals at outbreak thresholds, with follow-up survey flights to confirm knockdown.

Boron & micronutrient deficiency DRONE-LED

Physiological — hook leaf, little leaf, crown chlorosis

The most common "disease" in the Godavari and Telangana belts is not a pathogen at all. Hook leaf and malformed fronds signal boron hunger; chlorotic crowns signal magnesium and nitrogen gaps. Foliar correction by drone reaches the symptom directly while soil applications catch up.

Spindle / bud rot DRONE-ASSISTED WET SPELLS

Fungal-bacterial rot complex

Rot of the emerging spindle in prolonged wet weather, especially in young plantations. Protective canopy rounds by air; affected spindles cleaned and treated individually on the ground.

Ganoderma basal stem rot NOT A SPRAY PROBLEM

Ganoderma spp.

The great killer of ageing oil palm worldwide is a trunk-base and root disease. Detection, sanitation, soil mounding and drenching are the tools. Our aerial surveys can help you spot the canopy symptoms early across a big block; the treatment itself happens at ground level.

Rubber

Rubber diseases.

Abnormal leaf fall (ALF) DRONE-LED PRE-MONSOON

Phytophthora spp.

Rubber's century-old monsoon tax — first recorded in Kerala's estates in 1910, still shaving latex yield wherever the Southwest monsoon sits over the canopy. Traditional prophylaxis meant high-volume copper oxychloride sprayed up into 80-foot trees, one of the hardest spray jobs in Indian agriculture. That is exactly the job that has now moved to the air: the Rubber Board itself has turned to drone spraying to protect plantations against fungal leaf fall.

Signs
Pre-monsoon pod rot, then heavy green-leaf fall with dark lesions on the petiole during the rains; secondary crown thinning and yield drop.
Drone role
Block-wide prophylactic copper fungicide rounds completed before monsoon onset — the aerial route makes annual whole-estate coverage feasible for smallholders, not just large estates with micron-sprayer crews.

Pestalotiopsis / new leaf fall disease DRONE-LED

Pestalotiopsis spp. complex

The newer threat sweeping rubber across Asia — severe defoliation and latex loss reported through Indonesia, Malaysia, Thailand, Sri Lanka and India. Governments have reached for the same tool: in the Philippines, the Department of Agriculture's treatment plan for affected plantations includes drone aerial spraying of fungicide, and India's Rubber Board has deployed drone spraying against fungal leaf fall outbreaks. Managed as a response programme following current board advisories.

Signs
Circular leaf spots coalescing, yellowing, out-of-season heavy leaf fall, thin crowns and falling latex volumes.
Drone role
Rapid, repeatable canopy fungicide application at outbreak scale — the operational difference between treating a demonstration plot and treating a district.

Powdery mildew DRONE-ASSISTED REFOLIATION

Oidium heveae

Attacks the tender flush during annual refoliation (Jan–Mar). Traditionally managed by sulphur dusting on a tight schedule; aerial application can hold the schedule across large areas when the flush breaks everywhere at once.

Tapping panel dryness NOT A SPRAY PROBLEM

Physiological disorder

Latex simply stops flowing on part or all of the panel. It is a tapping-intensity and tree-physiology problem, managed through rest and revised tapping systems. No tank mix fixes it — from the ground or the air.

The evidence base

This is not an experiment anymore.

Karnataka

Drone spraying against arecanut koleroga and leaf spot has moved from university trials to routine practice across the Malnad and coastal belts, with state agricultural universities standardising crop-wise spray protocols.

India's Rubber Board

The Rubber Board has deployed drone spraying against fungal leaf fall disease, alongside disease-management formulations developed with public-sector partners — institutional endorsement at the highest level of the crop.

Across Asia

Oil palm estates in Malaysia and Indonesia, rubber authorities in the Philippines and Thailand, and orchard programmes in China have all standardised drone application for tall-crop protection — the global playbook we localise.

This guide is grower education, not a prescription. Confirm diagnoses with your Krishi Vigyan Kendra, agricultural university or commodity board officer; chemical choices always follow current labels and advisories.