Crop protection
Weeds, pests, diseases & deficiencies
A plain-language guide to the problems that cut Indian yields — how to spot each one, what causes it, and how to control it organically and with chemistry. Filter by the kind of problem you are facing.
Type of problem
Showing 143 of 143
- Nutrient deficiency
Nitrogen deficiency
The most common and most costly deficiency in Indian fields — an even, pale-green to yellow crop starting on the oldest leaves. Because nitrogen moves inside the plant, the bottom leaves go first while the top stays greener.
Affects 10NRead guide - Nutrient deficiency
Phosphorus deficiency
A dark, dull, stunted crop — often with a purple or reddish tinge on the older leaves and stems. Roots are poor, tillering and flowering are delayed, and the damage is worst when it strikes early because phosphorus drives establishment.
Affects 10PRead guide - Nutrient deficiency
Potassium deficiency
Scorching and yellowing along the edges and tips of the older leaves, while the middle of the leaf stays green. The crop wilts easily, lodges, and fills grain or fruit poorly — potassium is what makes a plant sturdy and drought-hardy.
Affects 10KRead guide - Nutrient deficiency
Sulphur deficiency
A pale-yellow crop that — unlike nitrogen — yellows from the top, on the youngest leaves first. It is now widespread in India, especially in oilseeds and pulses, because high-analysis fertilisers stopped supplying the sulphur that older ones did.
Affects 10SRead guide - Nutrient deficiency
Zinc deficiency
The most widespread micronutrient deficiency in Indian soils. It shows as pale bands or bronzing between the veins of young leaves, small "little-leaf" rosettes, and shortened stems — "khaira" in rice is its best-known face.
Affects 10ZnRead guide - Nutrient deficiency
Iron deficiency
A bright yellow young leaf laced with a fine network of green veins — "iron chlorosis". It is a lime-induced problem: the iron is usually in the soil but locked up by high pH, so it strikes hardest on calcareous soils and in fruit crops.
Affects 10FeRead guide - Nutrient deficiency
Boron deficiency
A deficiency of growing points and reproductive parts, not leaves — hollow or brown stems and hearts, cracked and corky fruit, dying tips, and flowers that fail to set. Cauliflower "browning", groundnut "hollow heart" and fruit cracking are its signatures.
Affects 10BRead guide - Nutrient deficiency
Calcium deficiency
Rarely a soil shortage, usually a delivery failure — calcium moves with water, so it starves the parts water reaches last: growing tips, and the far end of fruit. Blossom-end rot of tomato and "pops" of groundnut are the classic faces.
Affects 5CaRead guide - Nutrient deficiency
Magnesium deficiency
Interveinal yellowing on the older leaves — the veins stay a sharp green while the tissue between them goes yellow, then orange-red. Because magnesium is mobile, it strips the old leaves to feed the new, so the bottom of the plant goes first.
Affects 10MgRead guide - Nutrient deficiency
Manganese deficiency
Interveinal yellowing of the young leaves with a broad green band left along the veins — like iron chlorosis but duller, greyer and coarser. A high-pH problem, common in citrus and on over-limed or sandy soils.
Affects 5MnRead guide - Nutrient deficiency
Molybdenum deficiency
The one micronutrient that gets worse as soil turns acidic, not alkaline. It stops legumes fixing nitrogen and throws the strap-like "whiptail" of cauliflower and broccoli. Needed in the tiniest amounts of any nutrient.
Affects 6MoRead guide - Nutrient deficiency
Chlorine deficiency
The rarest deficiency in Indian farming — chloride is almost everywhere, in rain, irrigation water and fertiliser. When it does occur it wilts and mottles young leaves; coconut on inland, high-rainfall soils is the main crop where it is documented.
Affects 1ClRead guide - Pest
Aphids
Soft, pear-shaped sap-suckers that cluster on tender shoots and the underside of leaves. They curl and stunt growth, coat the plant in sticky honeydew and sooty mould, and — most costly of all — spread plant viruses as they feed.
Affects 10AphidoideaRead guide - Pest
Whitefly
Tiny white moth-like insects that rise in a cloud when a plant is shaken. They suck sap from leaf undersides and, far more damagingly, spread the leaf-curl and yellow-mosaic viruses that flatten cotton, tomato and pulse crops.
Affects 8Bemisia tabaciRead guide - Pest
Thrips
Slender, fast-moving insects barely visible to the eye that rasp the leaf and flower surface and drink the sap that oozes out — leaving silvery streaks, curled leaves and scarred fruit. Several species also spread damaging viruses.
Affects 9ThysanopteraRead guide - Pest
Jassids (leafhoppers)
Small, wedge-shaped green insects that sit on the underside of leaves and hop away sideways when disturbed. Their sap-sucking injects a toxin that yellows, bronzes and cups the leaf edges downward — the classic "hopper burn".
Affects 5Amrasca biguttulaRead guide - Pest
Mealybugs
Slow-moving sap-suckers wrapped in a white, waxy, cottony coat that shelters them from sprays. They mass on stems, leaf axils and fruit, drain the plant, and coat it in honeydew and sooty mould — and they are notoriously hard to wet.
Affects 5PseudococcidaeRead guide - Pest
Red spider mite
Not an insect but a mite — pinhead-sized specks on the underside of leaves that suck cell contents, stippling the leaf with tiny pale dots until it bronzes and dries. In heavy attacks they spin a fine webbing over the leaves.
Affects 6TetranychusRead guide - Pest
Fruit fly
The female stings ripening fruit and lays eggs under the skin; the maggots tunnel the pulp from inside, so the fruit rots and drops with no outward warning until it is too late. The single biggest pest of mango, guava and cucurbits.
Affects 4Bactrocera spp.Read guide - Pest
Helicoverpa (pod/fruit borer)
One caterpillar, many names — gram pod borer, tomato/chilli fruit borer, American bollworm, sunflower head borer. It bores into the very part you harvest (pod, fruit, boll, head), and its habit of moving plant to plant makes it hugely destructive.
Affects 6Helicoverpa armigeraRead guide - Pest
Spotted pod borer (Maruca)
The webbing pod borer of pulses. Its caterpillar ties flowers, buds and pods together with silk and feeds hidden inside the webbed mass — so it bores pods while sheltered from sprays and predators. A major pest of pigeonpea, moong and urad.
Affects 3Maruca vitrataRead guide - Pest
Fall armyworm
An invasive caterpillar that has become the number-one pest of maize in India since 2018. It feeds deep in the whorl of young plants, leaving ragged holes and wet sawdust-like frass, and can strip a crop fast if not caught early.
Affects 2Spodoptera frugiperdaRead guide - Pest
Termites
Soil-dwelling social insects that feed on roots, the underground stem and dead plant matter, killing scattered plants that wilt and dry with no obvious pest above ground. Worst on light soils, in dry spells, and where raw crop residue is present.
Affects 4Odontotermes spp.Read guide - Pest
White grub
The fat, C-shaped grub of the chafer beetle lives in the soil and chews through roots, killing plants in expanding patches. The adult beetles emerge in swarms at the first monsoon rains — the one window when they are easy to knock down.
Affects 3Holotrichia spp.Read guide - Pest
Stem borer (cereals)
A caterpillar that bores into the stem of maize, sorghum, millet and sugarcane. In young plants it kills the central shoot, leaving a dry "dead heart" that pulls out easily; later boring tunnels the stem and breaks it.
Affects 4Chilo / Sesamia spp.Read guide - Pest
Shoot fly
A small fly whose maggot cuts the central shoot of very young cereal seedlings, producing a "dead heart" within the first few weeks. Late-sown, slow-growing crops suffer most — the seedling stage is the whole battle.
Affects 4Atherigona soccataRead guide - Pest
Yellow stem borer (rice)
The main stem borer of rice. Its caterpillar tunnels the tiller and kills the central shoot — "dead heart" in the vegetative stage and, worse, "white ear" at panicle stage, where the whole earhead emerges empty and chaffy.
Affects 1Scirpophaga incertulasRead guide - Pest
Brown planthopper (rice)
Brown hoppers that mass at the base of rice tillers and suck sap until the plants dry in circular patches — "hopper burn". It thrives in dense, over-fertilised, closed canopies, and broad-spectrum sprays that kill its predators make it explode.
Affects 1Nilaparvata lugensRead guide - Pest
Rice leaf folder
A caterpillar that folds a rice leaf into a tube with silk and scrapes the green tissue from inside, leaving pale, papery, transparent streaks. Heavy folding of the upper leaves during grain filling is what costs yield.
Affects 1Cnaphalocrocis medinalisRead guide - Pest
Pink bollworm
The most serious pest of cotton today. Its pink caterpillar bores into flower buds and bolls and eats the developing seed and lint from inside — often invisibly, behind a "rosette" flower that never opens properly. It has broken Bt-cotton resistance in many areas.
Affects 1Pectinophora gossypiellaRead guide - Pest
Diamondback moth
The main pest of cabbage, cauliflower and other cole crops. Its small green caterpillar grazes the underside of leaves into pale "windows", and heavy attacks skeletonise the plant. It is notorious for developing insecticide resistance faster than almost any pest.
Affects 2Plutella xylostellaRead guide - Pest
Tobacco caterpillar (Spodoptera)
A voracious polyphagous caterpillar that feeds in swarms. Young larvae skeletonise leaves in groups; older ones scatter, hide in the soil by day and feed at night, defoliating soybean, groundnut, cole and many other crops fast.
Affects 4Spodoptera lituraRead guide - Pest
Brinjal shoot & fruit borer
The defining pest of brinjal. Its caterpillar bores into tender shoots (which wilt and droop) and then into the fruit, tunnelling the flesh out of sight — so the fruit looks fine outside but is bored and unsaleable inside.
Affects 1Leucinodes orbonalisRead guide - Pest
Epilachna (hadda) beetle
A spotted, ladybird-like beetle whose adults and spiny yellow grubs both scrape the green tissue between leaf veins, leaving a lacy skeleton of parallel scratch marks. It is the "vegetarian ladybird" — a pest of brinjal, cucurbits and potato, not a friend.
Affects 2Henosepilachna vigintioctopunctataRead guide - Pest
Red pumpkin beetle
A bright orange-red beetle that devastates cucurbit seedlings — the adults cut holes in the cotyledons and young leaves and can wipe out a stand at the two-leaf stage, while the grubs feed underground on roots and fruit touching the soil.
Affects 1Aulacophora foveicollisRead guide - Pest
Cutworm
A soil-dwelling caterpillar that comes out at night and cuts young seedlings clean through at the base, felling them like tiny logs. By day it curls up in a "C" shape in the soil beside the plant, so the culprit is out of sight.
Affects 4Agrotis spp.Read guide - Pest
Pod fly
A hidden pest of pigeonpea. The maggot develops entirely inside the pod, feeding on the developing seed, so the pod looks perfectly healthy from outside until you open it and find shrivelled, tunnelled or hollow grain.
Affects 1Melanagromyza obtusaRead guide - Pest
Girdle beetle
A soybean stem borer with a distinctive habit — the female cuts two neat parallel rings around the stem or branch and lays an egg between them. The part above the girdle wilts and dries, and the grub then tunnels down the stem.
Affects 1Obereopsis brevisRead guide - Pest
Leaf miner
A tiny maggot that tunnels between the two surfaces of a leaf, eating the green tissue and leaving winding, whitish "serpentine" trails. Heavy mining dries the leaves and, in seedlings and leafy crops, stunts the plant.
Affects 3Liriomyza / AproaeremaRead guide - Pest
Hairy caterpillar
Hairy, fast-moving caterpillars that hatch in swarms and defoliate crops in waves. When young they feed as a dense group on a few leaves; as they grow they march out across the field, stripping foliage as they go.
Affects 5Spilarctia / Amsacta spp.Read guide - Pest
Sorghum midge
A tiny orange fly whose maggot feeds inside the flowering sorghum floret, destroying the developing grain. The earhead ends up with blank, unfilled spikelets, and because it attacks only at flowering, synchronised sowing is the main defence.
Affects 1Stenodiplosis sorghicolaRead guide - Pest
Potato tuber moth
The main storage pest of potato, and a field pest too. Its caterpillar mines the leaves and stems in the field and, worse, bores into the tubers — especially exposed ones and those in store — riddling them with dark tunnels and rot.
Affects 1Phthorimaea operculellaRead guide - Pest
Mango hopper
The key pest of mango flowering. Wedge-shaped hoppers swarm the flower panicles, suck the sap so the flowers dry and drop, and shower honeydew that turns the tree black with sooty mould — cutting fruit set at its most critical stage.
Affects 1Idioscopus / Amritodus spp.Read guide - Pest
Citrus psylla
A small sap-sucking psyllid on the tender shoots of citrus — damaging in itself, but feared above all as the insect that spreads citrus greening (HLB), the incurable disease that is the biggest threat to citrus worldwide.
Affects 2Diaphorina citriRead guide - Pest
Pyrilla (sugarcane leafhopper)
A sugarcane leafhopper that sucks sap from the leaves in large numbers, drying them and coating the crop in honeydew and sooty mould that cut sugar. It is famously kept in check by a parasite (Epiricania) — so conserving that natural enemy is the key.
Affects 1Pyrilla perpusillaRead guide - Pest
Tea mosquito bug
A slender, long-legged bug that punctures tender shoots, leaves and fruit and injects a toxic saliva. Each feeding puncture leaves a dark, sunken, corky spot, and heavy attacks blight the flush — a major pest of tea, and of guava and cashew.
Affects 2Helopeltis spp.Read guide - Pest
Rhizome scale
A tiny scale insect that encrusts the rhizomes of ginger and turmeric, mostly in storage and on seed rhizomes. It sucks sap under a hard scale cover, shrivelling the rhizome, ruining its market value and reducing the sprouting of seed.
Affects 2Aspidiella hartiiRead guide - Pest
Sugarcane borers
A group of stem-boring caterpillars — early shoot borer, top borer, internode/stalk borer — that tunnel sugarcane at every stage. Early on they kill the shoot ("dead heart"); later they bore the growing point and the cane itself, cutting weight and sugar.
Affects 1Chilo / Scirpophaga spp.Read guide - Pest
Banana pseudostem weevil
A weevil whose grubs tunnel inside the banana pseudostem, riddling it with galleries until the plant weakens, oozes gum, and can snap or topple under the weight of the bunch. The damage is hidden inside the stem until it is advanced.
Affects 1Odoiporus longicollisRead guide - Pest
Banana rhizome weevil
Also called the banana corm weevil — a black weevil whose grubs tunnel the corm (rhizome) at the base of the plant, destroying the root and shoot base. Attacked plants grow poorly, produce small bunches and topple; it spreads on infested suckers.
Affects 1Cosmopolites sordidusRead guide - Pest
Rhinoceros beetle
A large black beetle with a horn that bores into the crown of coconut and other palms to feed on the soft growing tissue. It cuts the emerging fronds so they open with a characteristic V-shaped or fan-like wedge, and severe attacks kill the palm.
Affects 1Oryctes rhinocerosRead guide - Pest
Red palm weevil
The deadliest pest of coconut and palms. Its grubs tunnel unseen inside the trunk and crown, eating out the soft core, so the first clear sign — a wilting, collapsing crown — often means the palm is already beyond saving. Early detection is everything.
Affects 1Rhynchophorus ferrugineusRead guide - Pest
Coconut black-headed caterpillar
A caterpillar that lives in silk-and-frass galleries on the underside of coconut fronds and scrapes the green tissue, giving the older leaves a scorched, dried, brown look from below. Severe attacks make whole palms appear fire-swept.
Affects 1Opisina arenosellaRead guide - Pest
Pomegranate fruit borer (anar butterfly)
The "anar butterfly" — its caterpillar bores into the developing pomegranate fruit and eats the arils and seeds from inside, then invites rot through the entry hole. The fruit looks intact until it rots and drops. Bagging the fruit is the classic defence.
Affects 1Deudorix isocratesRead guide - Pest
Sesame leaf webber & capsule borer
The main pest of sesame (til). Its caterpillar webs together the top leaves and shoots and feeds inside, then bores into the flowers and capsules, eating the developing seed — so it hits the crop at every stage from shoot to seed.
Affects 1Antigastra catalaunalisRead guide - Pest
Sesame gall fly
A tiny midge whose maggot develops inside the sesame flower bud, turning it into a swollen green gall that never opens into a flower or forms a capsule — so every attacked bud is a lost capsule and lost seed.
Affects 1Asphondylia sesamiRead guide - Pest
Shoot borer (ginger & turmeric)
The main pest of ginger and turmeric shoots. Its caterpillar bores into the pseudostem and feeds inside, so the central shoot yellows and dries into a "dead heart" — and it also bores into the rhizome, opening it to rot.
Affects 2Conogethes punctiferalisRead guide - Pest
Citrus leaf miner
A tiny moth whose maggot mines silvery, snaking tunnels in the tender new citrus leaves, curling and distorting them. Beyond stunting young trees, its mines open the leaf to citrus canker bacteria, so it matters most on nursery and young plants.
Affects 2Phyllocnistis citrellaRead guide - Pest
Mango stone weevil
A weevil whose grub develops inside the mango seed (stone), completely hidden — the fruit looks and often tastes normal, but the seed is bored, and infested fruit is barred from export markets on quarantine grounds. A pest of quality and trade, not visible loss.
Affects 1Sternochetus mangiferaeRead guide - Pest
Bark-eating caterpillar
A caterpillar of fruit trees that hides by day in a tunnel bored into the trunk or branch and comes out at night to eat the bark under a protective web of silk and frass. It girdles branches, weakens the tree, and is worst in old, neglected orchards.
Affects 2Indarbela spp.Read guide - Pest
Painted bug
A small, brightly-marked black-and-orange bug that attacks mustard and other cole/oilseed crops at two ends — sucking sap from seedlings just after emergence, and from the maturing pods, where it shrivels the seed and cuts oil.
Affects 1Bagrada hilarisRead guide - Pest
Mustard sawfly
A dark, slug-like larva that feeds voraciously on mustard seedlings and young leaves, especially at dawn and dusk, biting holes and skeletonising them from the margins in. Heavy attacks on the seedling crop can require resowing.
Affects 1Athalia lugens proximaRead guide - Pest
Coconut eriophyid mite
A microscopic mite that lives packed under the tender bracts (perianth) of young coconuts, rasping the growing nut surface. It leaves triangular scarred, corky, cracked, distorted nuts and causes heavy button-shedding and reduced nut size.
Affects 1Aceria guerreronisRead guide - Pest
Turmeric leaf-roller (skipper)
The caterpillar of a skipper butterfly that cuts a flap of turmeric (or ginger) leaf, folds it into a tube fastened with silk, and feeds inside — leaving the leaves rolled, ragged and reduced, and the plant weakened in a heavy attack.
Affects 2Udaspes folusRead guide - Pest
Birds
Grain- and seed-eating birds — sparrows, parakeets, crows, doves and others — that feed on ripening heads and cobs, worst in sunflower, sorghum, pearl millet, maize and sown/ripening grain. Damage concentrates at the milk-to-dough stage and near tree lines.
Affects 1Passer / Psittacula / Corvus spp.Read guide - Disease
Powdery mildew
A white, powdery, flour-like coating on the upper leaf surface, shoots and pods that spreads to cover the plant, yellows and dries the leaves and shrivels grain or fruit. Unusually for a fungus, it thrives in dry weather with cool nights.
Affects 10Erysiphales (various fungi)Read guide - Disease
Downy mildew
Pale yellow angular patches on the upper leaf surface with a greyish-purple downy mould on the underside directly beneath them. Unlike powdery mildew it needs cool, wet, humid weather, and it can destroy a crop fast in a rainy spell.
Affects 8Peronosporales (various)Read guide - Disease
Anthracnose
A fungal disease of warm, wet weather that causes dark, sunken spots on leaves, stems and — most damagingly — fruit, often with pinkish spore masses in the centre. On chilli and fruit crops it rots the produce and causes "die-back" of shoots.
Affects 8Colletotrichum spp.Read guide - Disease
Rusts
Fungal diseases that erupt as powdery yellow, orange, brown or black pustules on the leaves and stems, which shed rust-coloured spores that stain your hand. They drain the plant, dry the leaves and shrivel grain — wheat rusts are the classic example.
Affects 6Puccinia and related fungiRead guide - Disease
Fusarium wilt
A soil-borne fungus that enters through the roots and blocks the water-conducting vessels inside the stem, so the plant wilts and dies despite moist soil — often one side or one branch first. Splitting the stem shows brown-stained tissue inside.
Affects 5Fusarium oxysporumRead guide - Disease
Bacterial wilt
A soil bacterium that causes sudden, complete wilting of a green plant, especially tomato, brinjal, chilli, potato and ginger, in warm, wet weather. The quick test: a cut stem oozes a milky white bacterial stream into a glass of water.
Affects 5Ralstonia solanacearumRead guide - Disease
Early blight
A fungal disease of potato and tomato that makes dark brown spots with concentric rings — a "target-board" look — on the older, lower leaves first. It spreads upward, dries the leaves and, in tomato, sinks dark leathery spots into the fruit.
Affects 2Alternaria solaniRead guide - Disease
Late blight
The most feared disease of potato and tomato — the one behind the Irish famine. In cool, wet, cloudy weather it makes fast-spreading water-soaked dark lesions with a white downy mould underneath, and can rot a whole crop within days.
Affects 2Phytophthora infestansRead guide - Disease
Alternaria blight / leaf spot
A common fungal leaf-spot and blight of mustard, cole crops, sunflower and pulses. It makes dark brown spots with concentric rings on leaves, stems and pods; on mustard the pod spots shrivel the seed and cut oil, and it carries on the seed.
Affects 6Alternaria spp.Read guide - Disease
Bacterial leaf blight (rice)
A serious bacterial disease of rice that yellows and dries the leaves from the tips and margins inward in wavy, water-soaked streaks. In young plants it can wilt whole seedlings ("kresek"); it spreads fast in warm, humid, rainy, wind-damaged crops.
Affects 1Xanthomonas oryzae pv. oryzaeRead guide - Disease
Cercospora leaf spot
A common fungal leaf spot of pulses, sesame, cole crops and many others — round to angular spots with grey or tan centres and dark reddish-brown margins. Heavy spotting yellows and drops the leaves, weakening the plant and cutting yield.
Affects 5Cercospora spp.Read guide - Disease
Tikka leaf spot (groundnut)
The major leaf-spot disease of groundnut — round dark brown spots (early and late leaf spot) that shed the leaves before harvest, cutting pod yield and haulm. The dropped leaves near maturity are the classic, costly sign.
Affects 1Cercospora / Cercosporidium personatumRead guide - Disease
Smut (cereals)
A group of seed- and soil-borne fungi that turn the grain or earhead of wheat, barley, sorghum, bajra and maize into a mass of black, sooty spores. Because most smuts ride on or in the seed, seed treatment is the single most effective control.
Affects 5Ustilago spp. and related fungiRead guide - Disease
False smut (rice)
A fungal disease of rice that turns individual grains in the panicle into velvety greenish-yellow to greenish-black balls (spore balls). Common in a wet, well-fertilised crop at flowering — it reduces grain and, in some varieties, taints the produce.
Affects 1Ustilaginoidea virensRead guide - Disease
Karnal bunt (wheat)
A partial bunt of wheat grain that turns the germ-end of some grains into a black, foul-smelling powder. It rarely cuts yield much but downgrades and can reject the grain because of the fishy smell, and it is a serious quarantine disease.
Affects 1Tilletia indica (Neovossia indica)Read guide - Disease
Red rot (sugarcane)
The most destructive disease of sugarcane — a fungus that reddens and rots the inside of the stalk, drying the cane and crashing both yield and sugar recovery. It is largely spread by diseased setts, so healthy seed and resistant varieties are the backbone of control.
Affects 1Colletotrichum falcatumRead guide - Disease
Rice blast
A fast-moving fungal disease of rice that makes spindle-shaped, grey-centred spots on the leaves and can rot the neck of the panicle (neck blast), breaking the head and emptying the grain. Worst with excess nitrogen, dew and cool, humid nights.
Affects 1Magnaporthe oryzae (Pyricularia oryzae)Read guide - Disease
Sheath blight (rice)
A soil-borne fungal disease of rice that makes greenish-grey, snake-skin-patterned lesions on the leaf sheaths near the water line and climbs up the plant. It is worst in a dense, heavily-fertilised crop and can lodge the plants and empty the grain.
Affects 1Rhizoctonia solaniRead guide - Disease
Damping-off (seedlings)
A soil- and seed-borne rot that kills seedlings in the nursery — either before they emerge, or by rotting the stem at soil level so the seedling topples and collapses. Worst in wet, over-watered, crowded, poorly-drained nurseries.
Affects 5Pythium, Rhizoctonia & Fusarium spp.Read guide - Disease
Dry root rot (charcoal rot)
A fungal root and stem rot of pulses, groundnut, cotton, soybean and many crops that strikes in hot, dry, stressed conditions — plants suddenly wilt and dry, and the root and stem base show shredded tissue peppered with tiny black specks (microsclerotia).
Affects 5Macrophomina phaseolinaRead guide - Disease
Collar rot / stem rot (Sclerotium)
A soil-borne fungus that rots the stem at the soil line of groundnut, chickpea, tomato, chilli and many crops. Look for a white cottony fungal mat and tiny mustard-seed-like brown sclerotia at the base, with the plant wilting and dying.
Affects 5Sclerotium rolfsiiRead guide - Disease
Sclerotinia stem rot
A fungal stem and stalk rot of mustard, sunflower, cole crops and many vegetables in cool, humid weather — a soft, watery rot with a white cottony growth and, inside the hollowed stem, large hard black sclerotia like rat droppings.
Affects 5Sclerotinia sclerotiorumRead guide - Disease
Rhizome rot / soft rot (ginger & turmeric)
The most serious disease of ginger and turmeric — a soft, watery rot of the underground rhizome and stem base in warm, waterlogged conditions. The pseudostem yellows and collapses and the rotted rhizome smells foul; whole clumps and patches are lost.
Affects 2Pythium spp. (with Fusarium & bacteria)Read guide - Disease
Bacterial soft rot
A bacterial rot that turns the fleshy tissue of potato, onion, cabbage, cauliflower and many vegetables into a soft, watery, foul-smelling mush. It enters through wounds and spreads fast in warm, wet, poorly-ventilated conditions and in storage.
Affects 5Pectobacterium / Dickeya (Erwinia) spp.Read guide - Disease
Yellow mosaic virus (YMV)
A whitefly-spread virus of mung, urd, soybean and other legumes that mottles the leaves with bright yellow and green patches, then yellows the whole plant. Early infection stunts the plant badly and slashes pod set — control means controlling the whitefly.
Affects 3Mungbean/Mung yellow mosaic virus (begomovirus)Read guide - Disease
Leaf curl virus
A whitefly-spread virus complex of chilli, tomato, cotton and other crops that curls, crinkles and cups the leaves, shortens the internodes and bushes the plant, and stops it flowering and fruiting. It is managed through the whitefly, not by curing the plant.
Affects 3Begomoviruses (chilli/tomato/cotton leaf curl)Read guide - Disease
Mosaic virus
A family of plant viruses that mottle the leaves with light and dark green (and yellow) patches, distort and blister them, and stunt the plant. Most are spread by aphids (and some by sap/seed), so control is about the vector and clean planting material.
Affects 4Cucumber/Papaya/Sugarcane mosaic viruses and alliesRead guide - Disease
Banana bunchy top
A serious aphid-spread virus of banana that bunches the new leaves into a stunted rosette at the top of the plant, with dark green "dot-and-dash" streaks along the veins and midrib. Infected plants rarely bunch or fruit and must be destroyed.
Affects 1Banana bunchy top virus (BBTV)Read guide - Disease
Citrus greening (HLB)
The most destructive disease of citrus worldwide — a bacterium spread by the citrus psylla that yellows the shoots blotchily, hardens and mottles the leaves, and gives small, lopsided, bitter, poorly-coloured fruit. Trees decline and become unproductive.
Affects 2Candidatus Liberibacter asiaticusRead guide - Disease
Grassy shoot (sugarcane)
A phytoplasma disease of sugarcane, spread mainly through infected setts, that turns the clump into a mass of thin, white-to-pale, grassy tillers with no cane formation. Because it rides on the seed, healthy seed and hot-water treatment are the key controls.
Affects 1Sugarcane grassy shoot phytoplasmaRead guide - Disease
Citrus canker
A bacterial disease of citrus that makes raised, corky, brown scab-like lesions with a yellow halo on leaves, twigs and fruit. It disfigures and downgrades the fruit, causes leaf and fruit drop, and spreads fast in warm, wet, windy weather.
Affects 2Xanthomonas citri subsp. citriRead guide - Disease
Panama wilt (banana)
A soil-borne Fusarium wilt of banana that yellows the older leaves from the margin inward, splits the pseudostem base, and browns the internal water-conducting tissue. It is long-lived in the soil and untreatable once established — clean suckers and resistant varieties are key.
Affects 1Fusarium oxysporum f. sp. cubenseRead guide - Disease
Sigatoka leaf spot (banana)
A fungal leaf-spot disease of banana that streaks and spots the leaves and, in a heavy attack, dries much of the foliage before bunch maturity. Losing leaf area cuts bunch size and makes the fruit ripen prematurely and unevenly.
Affects 1Mycosphaerella spp.Read guide - Disease
Blister blight (tea)
The most important leaf disease of tea in the wet, cool, high-rainfall season — a fungus that makes translucent spots on the young harvestable leaves that swell into white, powdery blisters, spoiling the plucked crop and weakening the bush.
Affects 1Exobasidium vexansRead guide - Disease
Bud rot (coconut)
A fungal (Phytophthora) rot of the growing bud (spindle) of coconut and other palms that rots the heart of the crown. The spindle leaf withers and pulls out with a foul smell; if the bud is killed the whole palm dies, so early action is vital.
Affects 1Phytophthora palmivoraRead guide - Disease
Guava wilt
A soil-borne wilt complex of guava that yellows and bronzes the foliage, wilts branch by branch, and browns the roots and internal stem tissue, killing the tree over one or more seasons. It is untreatable once advanced, so healthy plants and soil health are key.
Affects 1Fusarium spp. (with other soil organisms)Read guide - Disease
White rust
A disease of mustard and other crucifers that makes shiny, raised white pustules on the underside of leaves and, when it infects the flower stalk, swollen distorted "stag-head" growths that bear no pods. It is favoured by cool, humid, wet weather.
Affects 3Albugo candidaRead guide - Disease
Maize leaf blight (Turcicum/Maydis)
The major leaf blights of maize and sorghum — long, boat-shaped grey-green to tan lesions (turcicum) or smaller spots (maydis) that dry the leaves and, in a heavy attack before or during grain fill, cut yield sharply. Favoured by warm, humid, wet weather.
Affects 2Exserohilum turcicum / Bipolaris maydisRead guide - Disease
Brown spot (rice)
A fungal leaf and grain spot of rice, strongly linked to poor, nutrient-deficient or drought-stressed soils, that peppers the leaves with oval brown spots and spots and discolours the grain. It is the classic "hunger disease" that worsens on starved crops.
Affects 1Bipolaris oryzae (Helminthosporium oryzae)Read guide - Disease
Ratoon stunting (sugarcane)
A hidden bacterial disease of sugarcane, spread by the cutting knife and infected setts, that stunts the crop and thins the canes with almost no outward symptoms — the loss shows up as steadily declining ratoon yields. Hot-water-treated healthy seed is the key control.
Affects 1Leifsonia xyli subsp. xyliRead guide - Disease
Ergot (sugary disease)
A fungal disease of the flowering heads of pearl millet (bajra), sorghum and other cereals that first oozes sticky, sweet "honeydew" from the florets, then replaces grains with hard dark ergot bodies (sclerotia). These bodies are toxic, so ergot is a grain-safety as well as a yield problem.
Affects 2Claviceps spp.Read guide - Disease
Grain mould (sorghum/millets)
A fungal complex that colours and rots the developing grain of sorghum and millets when the crop matures in wet, humid weather — pink, grey, black or white mouldy grain that weighs less, germinates poorly and can carry mycotoxins. Early-maturing, coloured, compact-head types suffer most.
Affects 2Fusarium, Curvularia & other fungiRead guide - Disease
Nematodes (root-knot & others)
Microscopic soil worms that attack the roots — root-knot nematodes swell the roots into galls, others rot or stunt them — so the plant looks nutrient-starved, wilts in the heat and yields poorly despite good feeding. Hidden below ground, they are best managed before planting.
Affects 5Meloidogyne spp. and other plant-parasitic nematodesRead guide - Disease
Purple blotch (onion & garlic)
The major leaf disease of onion and garlic — small white-centred spots on the leaves and seed stalks that enlarge into purplish, zonate blotches, girdling and toppling the leaves. It weakens the bulb and can break the seed stalk, and is worst in warm, humid, wet weather.
Affects 2Alternaria porri (with Stemphylium)Read guide - Disease
Basal rot / white rot (onion & garlic)
Soil-borne rots that attack the base and roots of onion and garlic, in the field and in store — Fusarium basal rot softens and browns the base plate, while white rot coats it in white fluffy mould and tiny black sclerotia. Bulbs yellow, wilt, rot and fail to keep.
Affects 2Fusarium oxysporum / Sclerotium cepivorumRead guide - Disease
Black rot (crucifers)
The most serious bacterial disease of cabbage, cauliflower and other crucifers — V-shaped yellow lesions spreading in from the leaf margins with blackened veins, leading to leaf drop, stunting and rotted, unmarketable heads. It is seed-borne, so clean seed is the first defence.
Affects 2Xanthomonas campestris pv. campestrisRead guide - Disease
Club root (crucifers)
A soil-borne disease of cabbage, cauliflower and other crucifers that swells the roots into large distorted clubs, so the plant cannot take up water and nutrients — it wilts in the day, stunts and yields poorly. It thrives in acidic, wet soils and its spores survive for many years.
Affects 2Plasmodiophora brassicaeRead guide - Disease
Scab & black scurf (potato)
Two tuber-surface diseases of potato that blemish the skin and cut market value — common scab makes rough, corky, raised or pitted scabs, while black scurf sticks hard black crusts (like soil that won’t wash off) onto the tuber. Both are seed- and soil-borne and managed mainly through clean seed and soil conditions.
Affects 1Streptomyces scabies / Rhizoctonia solaniRead guide - Disease
Ascochyta blight (chickpea)
A devastating fungal blight of chickpea in cool, cloudy, wet weather — brown lesions with tiny dark dots (pycnidia) in rings on leaves, stems and pods that girdle the stems and break the plant down. It can destroy a crop in days and is spread by seed, debris and rain-splash.
Affects 2Ascochyta rabieiRead guide - Disease
Botrytis grey mould
A fungal grey mould that rots flowers, pods and fruit (and grape bunches) in cool, humid, wet weather, coating the affected tissue in a soft rot with fuzzy grey-brown mould. It thrives on dense, wet canopies and injured or senescing tissue and is a major cause of bunch rot in grapes and flower/pod drop in chickpea.
Affects 2Botrytis cinereaRead guide - Disease
Gummosis / foot rot (citrus)
A Phytophthora disease of citrus that rots the bark at the trunk base and root collar, oozing gum from cracks, girdling the trunk, and rotting the roots — the tree yellows, declines and can die. It is driven by wet, poorly-drained soil and deep planting of the graft union.
Affects 2Phytophthora spp.Read guide - Disease
Die-back & branch canker
A drying-back of shoots and branches from the tip inward in mango, citrus, pomegranate and other trees, often with sunken cankers on the wood — caused by fungi that enter through wounds and dead tips, especially on stressed or neglected trees. Pruning back to healthy wood and protecting cuts are central to control.
Affects 3Colletotrichum / Botryosphaeria and related fungiRead guide - Disease
Mango malformation
A disorder of mango that deforms the shoots and flower panicles — vegetative malformation makes a bunched rosette of stunted shoots, while floral malformation makes a compact, greenish, over-branched flower head that sets little or no fruit. It is linked to a Fusarium fungus and spreads on infected planting material.
Affects 1Fusarium mangiferaeRead guide - Disease
Little leaf & phyllody (phytoplasma)
Leafhopper-spread phytoplasma disorders that distort growth — little leaf makes brinjal throw a bushy mass of tiny leaves with no fruit, while phyllody turns sesame flowers into leafy green structures that set no seed. Both are incurable in the plant, so roguing and controlling the leafhopper vector are key.
Affects 2Phytoplasmas (leafhopper-transmitted)Read guide - Disease
Grey mildew (cotton)
A fungal leaf disease of cotton, common late in the season, that makes pale angular spots bounded by the veins with a frosty grey-white mould on the underside. Heavy infection yellows and sheds the leaves, cutting boll development and yield in the crucial late stage.
Affects 1Ramularia areolaRead guide - Disease
Sterility mosaic (pigeonpea)
A mite-spread viral disease of pigeonpea (arhar) that gives a pale mosaic and bushy, small-leaved growth and, above all, makes the plant sterile — it flowers little or not at all and sets no pods. An early-infected plant is a total loss, so it is called the "green plague" of pigeonpea.
Affects 1Pigeonpea sterility mosaic virus (mite-transmitted)Read guide - Disease
Bud necrosis / spotted wilt (tospovirus)
A thrips-spread virus group that causes ringspots, necrotic (dead) streaks and bud/tip death in groundnut, sunflower, tomato and other crops — early-infected plants are severely stunted, deformed and often killed. Because it rides on thrips, control means managing thrips early and roguing.
Affects 3Tospoviruses (thrips-transmitted)Read guide - Disease
Root (wilt) disease (coconut)
A chronic, debilitating phytoplasma disease of coconut that gradually saps the palm — the leaflets flex/ribbon and yellow, the crown thins, and nut yield falls steadily over years. It does not kill quickly but keeps a palm unproductive, and there is no cure once infected.
Affects 1Phytoplasma (coconut root wilt)Read guide - Disease
Ganoderma basal stem rot (coconut)
A lethal root-and-trunk-base rot of coconut (also called Thanjavur wilt/Ganoderma wilt) — the fungus rots the base of the trunk and roots, oozing reddish-brown gum from the trunk base, with bracket (shelf) fungi appearing on it. The crown wilts and the palm dies; it is soil-borne and hard to save once advanced.
Affects 1Ganoderma lucidumRead guide - Disease
Phytophthora blight
A fast, water-driven disease of chilli, pigeonpea and other crops in wet, waterlogged conditions — it damps off seedlings, rots the stem/collar and roots (wilting the plant), and blights leaves and fruit. It races through a wet, poorly-drained field, so drainage is the first line of defence.
Affects 2Phytophthora spp.Read guide - Weed
Phalaris minor (littleseed canarygrass)
The number-one weed of wheat in the north-west plains — a grass that mimics young wheat, so it is hard to spot early, competes fiercely for nitrogen and water, and has evolved resistance to several herbicides. Rotation and herbicide rotation are as important as the spray itself.
Affects 2Phalaris minorRead guide - Weed
Wild oat (Avena)
A tall annual grass weed of wheat, barley and gram that looks like an oversized cereal seedling and competes strongly for nitrogen and light. Its seeds shatter and drop before harvest, refilling the soil seed bank, so stopping seed set and rotating crops and herbicides are key.
Affects 3Avena ludoviciana / Avena fatuaRead guide - Weed
Barnyard grass / jungle rice (Echinochloa)
The most important grassy weed of rice (and a serious one in maize and other summer crops) — a fast-growing grass that mimics rice seedlings, competes heavily, and thrives in the flooded, warm conditions rice needs. Good land levelling, water management and timely herbicides are central to control.
Affects 3Echinochloa crus-galli / Echinochloa colonaRead guide - Weed
Bermuda grass / doob (Cynodon)
A tough perennial creeping grass that spreads by wiry surface runners (stolons) and underground rhizomes, forming dense mats in orchards, sugarcane, cotton and field edges. Because ploughing chops the rhizomes into new plants, it is very hard to kill and needs a persistent, integrated attack.
Affects 3Cynodon dactylonRead guide - Weed
Crabgrass & summer grasses (Digitaria/Setaria)
Fast-growing annual summer grasses of maize, sugarcane, groundnut and vegetables that spread low and root at the nodes, quickly covering the ground between young crop rows and competing for nitrogen and moisture. Early inter-cultivation, mulch and timely herbicides keep them down.
Affects 3Digitaria spp. / Setaria spp.Read guide - Weed
Purple nutsedge / motha (Cyperus)
One of the world’s worst weeds — a perennial sedge, not a true grass, that spreads by underground tubers ("nuts") joined in chains, so hoeing and ploughing just scatter the tubers and multiply it. It competes hard in almost every crop and is very hard to eradicate once established.
Affects 4Cyperus rotundusRead guide - Weed
Bathua (Chenopodium album)
The most common broadleaf weed of winter crops — a fast-growing annual with a mealy grey-white bloom on the young leaves that competes hard with wheat, gram, mustard and potato and sheds enormous numbers of seeds. It is also a familiar edible leafy green, but in the field it is a major yield-robber.
Affects 4Chenopodium albumRead guide - Weed
Amaranthus / chaulai (pigweed)
A fast-growing summer broadleaf weed of maize, cotton, sugarcane and vegetables that shoots up quickly, competes hard for nitrogen and light, and produces huge numbers of tiny long-lived seeds. Early inter-cultivation and timely herbicides before it seeds are the keys to control.
Affects 3Amaranthus spp.Read guide - Weed
Senji (sweet clover, Melilotus)
A winter broadleaf weed of wheat, gram and mustard — a fast-growing legume with clover-like trifoliate leaves and small white or yellow flowers that competes for nitrogen, water and light and can taint wheat flour if its seed contaminates the grain. Clean seed and timely control keep it down.
Affects 3Melilotus alba / Melilotus indicaRead guide - Weed
Blue pimpernel / krishnaneel (Anagallis)
A low, spreading winter broadleaf weed of wheat, gram and mustard with small blue (or reddish) flowers and paired leaves on a square stem. It carpets the ground between crop rows, competes for moisture and nutrients, and seeds prolifically; it is also poisonous to livestock if grazed.
Affects 3Anagallis arvensisRead guide - Weed
Horse purslane (Trianthema)
A low, fleshy, fast-spreading summer broadleaf weed of cotton, groundnut, soybean and vegetables that carpets the ground rapidly after the first rains, competing hard with young crops for moisture and nitrogen. Its succulent stems re-root, so it must be removed cleanly and controlled early.
Affects 3Trianthema portulacastrumRead guide - Weed
Purslane / kulfa (Portulaca)
A low, fleshy, mat-forming summer broadleaf weed of vegetables, maize and groundnut with succulent red stems and thick paddle-shaped leaves. It survives drought and hoeing (uprooted plants can re-root and even ripen seed), competes with young crops, and seeds prolifically — so it must be removed cleanly.
Affects 3Portulaca oleraceaRead guide - Weed
Parthenium (congress grass, carrot weed)
An aggressive invasive broadleaf weed of field edges, wastelands, orchards and many crops that grows fast, seeds prolifically all year, and displaces other plants. It is also a serious health hazard — causing dermatitis and asthma in people and harming livestock — so it must be removed before it flowers.
Affects 3Parthenium hysterophorusRead guide - Weed
Lantana (Lantana camara)
An aggressive invasive thorny shrub that forms dense impenetrable thickets on plantation margins, wastelands, forest edges and grazing land, crowding out other plants and useful pasture. It spreads by bird-carried berries and re-sprouts from the roots after cutting, and its foliage is toxic to livestock.
Affects 3Lantana camaraRead guide - Weed
Dayflower / kena (Commelina)
A succulent, creeping broadleaf weed of rice, maize, sugarcane and vegetables with bright blue flowers that roots at its nodes and even sets seed underground, so it is hard to kill by hoeing and shrugs off some herbicides. Clean removal and integrated control are needed to keep it down.
Affects 3Commelina benghalensisRead guide - Weed
Piazi / wild onion (Asphodelus)
A winter weed of mustard, gram, barley and other rabi crops on light, sandy soils, with onion-like hollow leaves growing from a basal tuft and small white flowers. It competes for moisture and nutrients in dryland crops and seeds prolifically, so clean seed and early control keep it down.
Affects 3Asphodelus tenuifoliusRead guide - Weed
Dock / jangli palak (Rumex)
A winter broadleaf weed of wheat, barley and berseem in moist, heavy or waterlogged fields, with a rosette of spinach-like leaves and tall spikes of green flowers turning rusty-brown. It competes strongly where water stands and seeds heavily, so drainage plus timely broadleaf control keep it down.
Affects 2Rumex dentatusRead guide - Weed
Parasitic weeds (Striga, Orobanche, Cuscuta)
Weeds that attach to and feed off the crop itself — Striga (witchweed) on sorghum, maize and millets; Orobanche (broomrape) on mustard, tomato and tobacco; and Cuscuta (dodder, amarbel) twining over many crops. Because they draw nutrients directly from the host and shed huge long-lived seed, control means clean seed, resistant varieties and stopping seed set.
Affects 3Striga / Orobanche / Cuscuta spp.Read guide
Facing a problem on a specific crop? Each crop guide lists its own weeds, pests, diseases and deficiencies in the order you meet them.
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