The spice supply chain
Quick answer
Most spices pass through several hands between the farm and the jar — collectors, processors, exporters, importers, treatment plants, grinders and packers — and each handover is a point where quality is kept or lost and where a product can be misdescribed. This page sets out those stages, what the paperwork that travels with a lot can and cannot show, why some chains are more exposed than others, what certification schemes verify, and what is documented about the labour behind spices, with each piece of evidence labelled for what it is.
From farm to shelf
Not every spice passes through every stage; a smallholder selling to a local market skips most of them.
1. Farm or wild harvest
Most spices begin on small farms and home gardens, and some are gathered from wild or semi-managed stands rather than planted. Drying is usually done where the crop is grown, often in the open air.
Where it goes wrong:Open-air drying, often on the ground, is where contamination from soil, animals and birds enters, and where slow drying lets mould grow.
2. Collector or local aggregator
Small lots from many growers are bought by collectors and village traders and bulked into saleable quantities. In Madagascar’s vanilla chain, collectors buy green or cured beans from smallholders and sell them on to processors and exporters.
Where it goes wrong:Bulking mixes lots from many farms, so the origin of any one portion of a consignment becomes hard to establish, and every further hand is another point at which material can be added or swapped.
3. Primary processor
Crops that must be cured, sorted or graded before export — vanilla, cardamom, pepper, cinnamon
Curing, cleaning, sorting and grading into trade grades, often in the producing country. For some crops — vanilla curing, cardamom curing, Sri Lankan quill making — this is where most of the quality is made.
4. Trader and exporter
Exporters assemble graded lots to buyers’ specifications, arrange testing and documents, and ship. Production of several spices is concentrated in a handful of exporting countries.
5. Importer
The importer receives the consignment into the destination market, where it can be sampled at entry. FDA sampling of imported spice shipments at entry found Salmonella and filth at higher rates than in other imported foods.
Where it goes wrong:The point at which destination-market testing usually begins; problems found here are problems made earlier in the chain.
6. Cleaning and microbial treatment
Most spices sold ground or used in ready-to-eat foods
Imported spices are commonly cleaned to remove foreign matter and then treated to reduce microbes — by steam, irradiation or, in the United States, ethylene oxide — before milling or sale. The treatments and their effects are set out on the food-safety page.
7. Grinder, blender and packer
Whole spice is milled, blended with other ingredients and packed, often by the brand that sells it. Grinding removes the visual evidence of identity, which is why most documented adulteration concerns ground and powdered products.
Where it goes wrong:The last stage at which material can be added unseen: once a spice is a powder, fillers and cheaper species cannot be picked out by eye.
8. Distributor
Packed product moves through wholesalers and distributors to shops, caterers and food manufacturers; storage conditions here affect quality rather than safety for a properly dried spice.
9. Retail, foodservice and manufacturing
The end of the chain: supermarket and specialist shelves, restaurant kitchens, and food manufacturers who use spices as ingredients in other products — the route by which a contaminated spice reaches many foods at once, as the 2009–2010 pepper outbreak on salami showed.
The processing at each stage is on how spices are produced; what traceability can prove is on the authenticity register.
What a certificate of analysis shows
The measurements that commonly travel with a lot. Which ones are required, and at what limits, depends on the product, the buyer and the jurisdiction; there is no single specification.
- Moisture
Whether the spice was dried well enough to keep: a dry spice cannot support mould growth, a damp one can. It says nothing about identity or flavour.
Method:Maximum moisture contents appear in the Codex spice standards and the European industry minima.
- Volatile oil
How much of the aromatic fraction remains — a measure of strength and freshness for spices whose character is aromatic. It cannot tell whose oil it is: a cheaper species can have plenty.
Method:Minimum volatile-oil contents are set in the ISO and Codex specifications for several spices.
- Total ash
The mineral residue after burning, which rises when a spice carries soil, dust or added mineral matter. A high figure is a warning; a normal one does not rule out organic fillers.
- Acid-insoluble ash
The part of the ash that does not dissolve in acid — essentially sand and silica — and so the clearest single measure of soil and grit picked up in drying or added as weight.
- Extraneous and foreign matter
Stems, other plant parts, stones, insects and other material that is not the spice, found by inspection of the whole product. It is only meaningful before grinding.
- Microbiological results
Counts of total bacteria, yeasts and moulds, and tests for pathogens such as Salmonella and indicators such as E. coli. A negative Salmonella result describes the samples tested; because contamination is patchy through a lot, it lowers the likelihood of a problem rather than excluding it.
- Aflatoxins and ochratoxin A
Whether the lot is within legal limits for these mould toxins, which survive drying and treatment. Relevant above all to chilli, pepper, nutmeg, ginger and turmeric, the spices named in the EU limits.
- Pesticide residues
Which residues were found, if any, against the limits of the destination market. A clean result covers only the substances the laboratory looked for.
- Heavy metals
Lead and other metals against legal limits, where they exist. Elemental analysis also detects lead chromate added as colour to turmeric, which no organic test would see.
- Colour and active compounds
Extractable colour for paprika and chilli, and the content of characteristic compounds — piperine in pepper, curcuminoids in turmeric, capsaicinoids in chilli — as measures of strength and grade. Added dyes can raise a colour figure, which is why colour alone is not proof of quality.
Why some supply chains are vulnerable
The conditions under which fraud, contamination and price shocks are most likely — not a verdict on any trader.
High value by weight
The dearer a spice per kilogram, the more a small addition of cheaper material is worth; saffron and vanilla are the standing examples in the fraud literature.
Sold ground
Grinding destroys the visual evidence of identity, so fillers and cheaper species pass unseen; most documented adulteration concerns powders.
Chilli powder, Paprika, Turmeric, Cumin, Black pepper, Oregano
Long chains with many intermediaries
Spice supply chains are long and pass through many hands between smallholder and packer, and the fraud literature identifies each transfer as an opportunity for adulteration.
A cheaper look-alike exists
Where a cheaper plant material resembles the spice once dried or ground — olive leaf in oregano, safflower in saffron, cassia sold as cinnamon — substitution is easy to do and hard to see.
Drying in the open
Drying on the ground or in the open exposes the crop to soil, animals and birds, which is how Salmonella and filth enter before any treatment step.
Concentrated production exposed to weather
Where most of a crop comes from one exposed region, one storm can move the world price: north-eastern Madagascar, which grows most of the world’s vanilla, lies in the path of Indian Ocean cyclones.
When supply has been disrupted
Documented cases in which a storm, a disease, a policy or a price collapse materially disrupted a spice supply — what happened and what followed. A record of the past, not a forecast.
Crop disease · Singapore and Penang · 1860s
Nutmeg planting in Singapore and Penang, begun after the Dutch monopoly was broken, collapsed in the 1860s. The crop handbook attributes the collapse to a bark beetle that bores through the bark and cambium of the trunk and kills the tree — a pest rather than a disease in the strict sense.
What followed:Of the centres of nutmeg cultivation founded outside the Moluccas in that period, the handbook records that all disappeared again, some of them to disease, with one exception: trees taken to Grenada in 1843 grew into the industry that made the island the second-largest producer after Indonesia.
Price collapse · Madagascar and Zanzibar · 1983 and the years after
Indonesia, which burns most of the world’s cloves in kretek cigarettes, had been the main buyer of African cloves. After two decades of planting it became self-sufficient for the first time in 1983 and stopped importing, and exports from Madagascar and Zanzibar fell sharply. The demand that vanished was the larger part of the market: use of cloves as a spice had long been flat at a few thousand tonnes a year.
What followed:Malagasy growers faced a slump in sales, and some considered uprooting their trees. The New York price of cloves, US$ 11 a kilogram in 1982, stood at US$ 1.25–1.45 for East African cloves in 1996 and 1997. Madagascar’s crop has since been sold largely through Singapore into Indonesia as a top-up to Indonesian production, so that its exports rise when the Indonesian harvest falls, as in 1999–2001.
Drought · Southern India (Karnataka, Kerala and Tamil Nadu) · 1982–1983
The drought of 1982–83, which a review in India’s meteorological journal calls unprecedented in the summer of 1983, cut the growth and yield of cardamom in Coorg and across the other cardamom tracts of southern India. On some estates as many as half the plants died.
What followed:A dead clump is not a lost season but a lost planting: a new cardamom plant gives its first small crop only in the third year after it is set out. The same review records that the area under cardamom in the Western Ghats has since declined sharply while production and yield per hectare rose.
Cyclone · SAVA region, north-eastern Madagascar · 2000–2004
Cyclone Hudah crossed Madagascar’s main vanilla region in 2000 and devastated the crop; national production is reported to have fallen to about 600 tonnes.
What followed:World supply tightened and the price climbed to several hundred US dollars a kilogram by 2003; a study of the price series identifies a bubble running from early 2001 to the end of 2004. The high price pushed manufacturers towards synthetic vanillin, demand for the natural product fell, and the market crashed in 2004 — to about US$ 30 a kilogram in 2005, low enough that growers turned to other crops.
Cyclone · Grenada · September 2004 and the years after
Hurricane Ivan struck Grenada, then the world’s second-largest nutmeg producer, in September 2004. The World Bank reported up to 85 per cent of the nutmeg crop damaged and 60 per cent of the trees destroyed outright; the regional damage assessment first put the loss at 90 per cent and later revised it to 70 per cent of about 12,000 acres.
What followed:Grenada normally sold about five million pounds of processed nutmeg a year. In the year after the storm it sold about 1.25 million, much of it from the growers’ association’s reserve stock, while world prices rose. Recovery was bound to be slow: a replanted seedling takes five to six years to fruit and ten to mature, and most growers were elderly people who treated their trees as a pension and were reluctant to replant. The association’s own target was half of pre-storm output within three years.
Drought · Central Highlands, Vietnam · 2015–2016
The El Niño drought of 2015–16 hit the perennial cash crops of Vietnam’s Central Highlands hardest. Provincial officials reported about 9700 ha of pepper in Dak Lak and 1650 ha in Gia Lai with losses by mid-May 2016, and communities interviewed across the region put their pepper yield losses at 79 per cent. Vietnam then supplied about a third of the world’s pepper.
What followed:Many plantations were killed outright and needed complete replanting, a cost the assessment judged not all farmers could meet, with years without income before new vines bear. It recommended drought-tolerant planting material and warned against clearing forest to replace lost plantations.
Cyclone · Madagascar and the world market · 2017–2018
Cyclone Enawo struck Madagascar’s vanilla coast in 2017, when the market was already tight: demand for natural vanilla had been rising since manufacturers began moving away from synthetic vanillin, and the price had climbed from about US$ 80 a kilogram in 2014. It reached about US$ 600 a kilogram, a record, by May 2018. The study of the price series names the cyclone as one cause beside rising demand, speculation by large buyers and falling quality.
What followed:Theft from the vines rose with the price, and growers picked pods early for fear of losing them, which lowered the quality of the cured vanilla. High prices again turned some buyers back to vanillin.
Flood · Kerala, India · August 2018
The floods and landslides of August 2018 damaged 14,650 ha of pepper in Kerala, about a sixth of the state’s 85,210 ha, according to the post-disaster assessment, which valued the damage at INR 259 crore and counted pepper as 19 per cent of the state’s lost crop production. It lists pepper, areca nut, banana and coconut as the perennial crops worst affected, with the hill districts of Idukki and Wayanad particularly badly damaged.
What followed:The assessment stressed that losing perennial crops costs growers more than one season — from a year’s earnings for banana to more than seven for rubber — and that soil washed away or buried by landslides, new disease and weeds could prolong the damage in the hill districts.
Price collapse · North-eastern Madagascar · 2020
Vanilla prices collapsed at the start of 2020 from the heights of 2018, as buyers disappeared and demand fell with the COVID-19 pandemic, in a region still recovering from Cyclone Enawo.
What followed:In interviews in two vanilla-growing villages, 87 per cent of respondents reported lower incomes from the fall in vanilla prices and 10 per cent a total loss of cash income; 62 per cent said they had cut back on food, chiefly rice. Farmers who had hired labour stopped doing so, and because vanilla growers are the main customers in the village, the prices of other crops fell too. These are findings for two villages, not for the region.
Crop disease · Andhra Pradesh, Telangana and Karnataka, India · November and December 2021
Cayenne pepper, Kashmiri chilli, Chilli powder
In late 2021 an invasive flower thrips, Thrips parvispinus, swept through the chilli crop of southern India as it came into flower and fruit — an insect pest, not a disease in the strict sense. A joint survey by the federal plant protection directorate and the state agricultural universities and departments, as reported by the entomologists who identified the insect, put the infested area at more than 0.4 million hectares and the yield loss at 10 to 30 per cent. Their own survey found more than 60 per cent of the chilli area affected in the main chilli districts of the three states, with the heaviest infestations, around twenty thrips to a flower, in Guntur in Andhra Pradesh and Khammam, Mahabubabad and Warangal in Telangana.
What followed:The insect had been recorded in India since 2015 on papaya and other plants without reaching chilli on this scale. A climate model in the same study rates Andhra Pradesh, Telangana, northern Karnataka and northern Tamil Nadu as highly suitable for it, which is a statement about climate and not a forecast of further outbreaks.
What certification verifies, and what it does not
A logo verifies what the scheme audits and nothing more.
EU organic
European UnionThat the product was produced and handled under the EU organic rules, which among other things exclude ionising radiation throughout the organic food chain — so an organic spice sold in the EU has not been irradiated.
That the spice is authentic or of any particular grade: organic certification regulates how a product is produced, and authenticity is established by testing the product itself.
USDA organic
United States Department of Agriculture, National Organic ProgramThat the product was produced and handled under the US organic rules, which exclude ionizing radiation from anything sold or labelled organic.
That the spice is authentic or of a particular grade, for the same reason as any production standard: authenticity is a property of the product, established by testing it.
Fairtrade
Fairtrade InternationalTrading terms for the producers: a Fairtrade Minimum Price for some herbs and spices, such as vanilla, and a Fairtrade Premium on top of the price; where there is no Minimum Price, a Premium of 15 per cent on the commercial price.
The quality, grade or authenticity of the spice itself. The scheme’s stated terms concern price and premium paid to producers, not the product’s composition.
Rainforest Alliance
Rainforest AllianceThat the farm or company met the scheme’s Sustainable Agriculture Standard, or its newer Regenerative Agriculture Standard, as checked by independent auditors on periodic visits.
The authenticity, grade or composition of a spice. The scheme is best known on coffee, tea, cocoa and bananas, and its own account does not list which spices carry the seal.
Labour
Ordered by the strength of the evidence. A sector risk assessment describes where problems are likely, not a finding about any farm; a description of how work is done implies nothing about how well it is paid or treated.
Documented incidence
Thirty-two communes of the SAVA region, Madagascar · Vanilla
A household survey carried out for the International Labour Organization in 2018, covering 895 children aged 5 to 17 in the four vanilla districts, found 16.6 per cent of children in child labour as the survey defined it and 11.1 per cent doing work classed as hazardous. Most of that work was not in vanilla: 10.5 per cent of the children in child labour, 1.7 per cent of all children surveyed, worked in the vanilla sector, and 4.2 per cent of all children had done work directly tied to vanilla growing, such as preparing ground or picking pods, in the previous twelve months. About half of working children were unpaid. The report states that its figures hold for the 32 communes surveyed and must not be extended to the rest of Madagascar.
Sector risk assessment
Madagascar · Vanilla
The Fair Labor Association’s 2021 field assessment of one plantation and smallholder farms in Madagascar reported child labour as prevalent, children doing hazardous work such as carrying heavy loads and using knives and machetes, and low awareness of child-labour standards. It also reports a 2012 ILO study estimating about 20,000 children aged 12 to 17 working in vanilla production, more than 30 per cent of the sector’s workforce. These are findings from assessed supply chains and a second-hand national estimate, not a survey of every producer. A household survey for the ILO in 2018 measured something different and found far less: 1.7 per cent of all children surveyed in the four vanilla districts were in child labour in vanilla. The two figures count different populations and should not be read as a trend.
How the work is done
SAVA region, Madagascar · Vanilla
Most Malagasy vanilla is grown by smallholders in the north-eastern SAVA region, whose output depends on how many household members can work through the short harvest, and who sell to collectors who resell further up the chain.
Vanilla-growing regions outside Mexico · Vanilla
Every flower is pollinated by hand on the one morning it opens, and every pod is picked by hand as it ripens, so the crop is two passes of manual work before curing begins.
Saffron-growing regions · Saffron
The flowers open over a few weeks in autumn and are picked by hand each morning, and the stigmas are separated from each flower by hand the same day — the labour that makes up most of saffron’s cost.
India and Guatemala · Green cardamom
Capsules ripen over months and are picked by hand in repeated rounds through the season, the largest part of the cost of producing cardamom.
Sri Lanka · Cinnamon (Ceylon)
The inner bark of coppiced shoots is scraped, loosened and peeled by hand and rolled into nested quills — skilled work whose quality shows directly in the grade.
East coast of Madagascar (Analanjirofo and Sainte-Marie) · Cloves
Picking cloves and stripping the buds from their stems is short-lived but highly labour-intensive work, and the supply of hands, not of trees, limits the harvest. A review of the Malagasy sector records that growers on Sainte-Marie, beyond family labour, have used casual labour, which gave poor yields, and sambiamanana, an arrangement that splits the harvest half and half between the owner of the trees and the picker. The review also lists forced labour among the means growers there have resorted to, without saying when.
Indonesia · Cloves
The right stage for picking lasts only a few days and a tree is picked three to eight times in a season, by climbers with baskets, ropes and crooks or from propped ladders; an experienced picker gathers some 40 kg of green cloves from good trees in a day. Because the season moves from May–June in East Java to November–December in Ambon, migrant workers follow the ripening crop through the main producing areas. In a heavy year a substantial part of the crop is often not picked at all.
Zanzibar (Unguja and Pemba), Tanzania · Cloves
Zanzibar’s clove growers sell to a single legal buyer. The Zanzibar State Trading Corporation was set up in 1968 as the lawful buyer and exporter of cloves, and the growers’ associations were abolished with it, so that farmers have no part in setting the price they are paid. A United Nations University study of 1980–2020 found exports rising with the producer price and falling over the period, and describes the local price as low and unstable; production, about 16,000 tonnes a year in the 1970s, ran at 1500–3500 tonnes in the 2000s. Since 2011 the corporation has also been charged with raising producer prices, lending without interest and supplying seedlings.
The World Bank’s review of Grenada after Hurricane Ivan found that most nutmeg growers were of the older generation — the growers’ association described its younger farmers as about sixty — and that many Grenadians regard the proceeds of nutmeg as a kind of pension. Age made it hard for them to clear fallen trees and replant, which the review saw as putting a full recovery of the crop in doubt.
Two villages in north-eastern Madagascar · Vanilla
When the vanilla price fell in 2020, growers interviewed in two villages said they could no longer pay for hired help and took on the work of their vanilla plots and rice fields themselves. Nearly half of the respondents with a second income earned it as farm labourers, so the same price fall removed that work. Interview evidence from two villages; it shows how a price shock passes from growers to the labourers they employ, not how common this is.
South-western Sri Lanka · Cinnamon (Ceylon)
Peeling cinnamon began as a caste obligation. The people later called Salagama were settled on land in return for gathering wild cinnamon and delivering it processed as tribute, a duty the Portuguese and Dutch took over; many were at first unwilling, the work being compulsory and the foraging hard, and the Dutch turned from wild harvest to planted cinnamon around 1770. The skills still pass mainly within families. Engineers at the University of Moratuwa report that younger people are leaving the trade for its drudgery and low standing, that the island is short of about 30,000 peelers, and that peelers now take 35–50 per cent of the sale value as their fee — the shortage that has prompted attempts to mechanise peeling.
Environmental trade-offs
Documented dimensions, each stated as a trade-off. SpiceHQ does not label spices sustainable or unsustainable.
Biodiversity · Western Ghats, India; Guatemala
Cardamom is grown under a retained or planted forest canopy, which keeps tree cover on hill slopes that might otherwise be cleared; it also involves thinning that canopy and clearing the understorey to let the crop through. Both halves are true at once.
Energy used in processing
Green cardamom, Black cardamom
Both cardamoms are dried with heat soon after picking — green cardamom in heated curing houses, black cardamom over open fires in kilns — so fuel is an input to every kilogram, and drying method bears on both quality and energy use.
Land use and forest cover · Sikkim, Darjeeling, eastern Nepal and Bhutan
Grown on terraced hill slopes beneath shade trees, classically the nitrogen-fixing Himalayan alder: a system that keeps tree cover on steep ground and depends on it.
Land use and forest cover · Madagascar
Vanilla grows on living support trees, often under a taller canopy, so an established plot keeps tree cover; where new plots are cut from forest, the reverse holds. Which of the two a given plot represents depends on where it was planted.
Biodiversity · North-eastern Madagascar
What a vanilla plot does for wildlife depends on what stood there before. In a study of seven groups of plants and animals across thirty Malagasy vanilla agroforests, plots made by thinning forest held 23 per cent fewer species and 47 per cent fewer endemic species than old-growth forest, while plots planted on fallow land held 12 per cent more species and 38 per cent more endemics than the fallows they replaced. Yield did not depend on that history, and for most groups higher yield did not mean fewer species; but denser planting and longer vines went with fewer tree species, and butterflies and reptiles showed trade-offs with yield. About 70 per cent of the agroforests in the region studied were on former fallow.
Crop resilience · East coast of Madagascar
Malagasy clove trees give two products, and one is taken at the expense of the other. The top half-metre of the branches is cut for distilling leaf oil in village stills, which brings a household income whenever it is needed and keeps the tree low, easier to pick and less exposed to wind. But observers since the 1930s have held that stripping the foliage so drastically reduces the crop of buds, and a regional decree of 2011 bans distilling in May and June, when the coming flower crop can be judged. A review of the sector warns that an ageing stock of trees, recurrent cyclone damage and over-collection of leaves may together outrun replanting.
Land use and forest cover · East coast of Madagascar
Pure stands of clove have all but disappeared in Madagascar. The trees now grow in agroforestry systems that range from cloves over rice, maize or cassava to tree gardens with coffee, mango and coconut, and pasture under cloves. Growers took up the tree partly because it yields on poor soils that will not carry coffee, and the review that describes this also records that it was planted at times at the expense of food crops, upland rice in particular.
Water · Idukki high ranges, Kerala, India
The spice crops of Kerala’s high ranges are grown in a forest setting and depend on its water. A study of the state’s climate and cropping records concludes that deforestation, shifts in cropping, the loss of wetlands and the depletion of surface and groundwater have deepened the effect of floods and droughts on spices and plantation crops, and notes that heavy pumping of groundwater for irrigation in the high ranges made the drought of 2016 worse. Irrigation protects a season’s crop and draws down the reserve the next drought will need.
Crop resilience · Sikkim, India
Large cardamom supplied about half of household income in the Sikkim Himalaya before 1997 and 29 per cent in 2016, with low productivity on more than half the cultivated area; the study that reports this attributes the decline of the past decades to erratic climate, diseases and pests and human pressure together, without separating them. Surveying 41 plantations between 975 and 2069 m, it found growers moving cultivars out of their customary altitude bands — low-elevation types upward, a high-elevation type downward — and found that each cultivar still yielded best within its own band. Moving a cultivar is an adaptation with a cost.
Energy used in processing · Eastern Nepal and Sikkim, India
Large cardamom comes off the plant at 70–80 per cent moisture and is dried within the plantation in a bhatti, a wood-fired pit over which the capsules lie 25–30 cm deep on a bamboo mat for 24 to 28 hours, in the smoke as well as the heat. The bhatti costs little and needs no special knowledge to build; it also chars and cracks a share of the capsules, darkens them and lowers their oil. Dryers that keep the smoke away from the crop, including a gasifier design that burns the wood more completely, give a cleaner product, yet a review found them rarely used, for reasons of cost, availability and familiarity. The smoky character that the kitchen prizes is a by-product of the cheaper method.
Pressure on wild populations · South-western Ethiopia
Korarima fruits are mostly gathered from plants growing wild in the shade of moist highland forest, the same habitat as wild coffee. That makes the supply only as secure as the forest: the species account recommends collecting and conserving its diversity because the mountain forests are being rapidly degraded, and a later study describes the plant’s habitat as shrinking through agricultural expansion and the logging of shade trees, and its status as declining outside protected areas. Gathering needs no cleared land, and it has no defence when the forest goes.
Pressure on wild populations · Chaharmahal and Bakhtiari province, Iran
Persian shallot is a wild plant whose bulb is the harvest, so each one gathered is a plant removed. Researchers working in one Zagros province report that indiscriminate collecting, together with habitat destruction and grazing, has reduced many populations, while the plant has for generations been an important source of income for local people. They recommend restricting collection and grazing in its habitats and bringing the plant into cultivation — which would shift the income from gatherers to whoever farms it.
Water · Shiraz, south-western Iran
Saffron’s growing season falls in the cool months, when little water evaporates, which is one reason its area has expanded in dry regions of Iran where groundwater is the main source of irrigation. A six-season field experiment at Shiraz found the largest yields, 12–13 kg of saffron a hectare, with about 830–870 mm of rain and irrigation together; halving the irrigation lowered average yield from 8.5 to about 7.3 kg a hectare, and water of moderate salinity cut total yield by 22 per cent while soil salinity roughly doubled over the life of the planting. The crop needs less water than most, and is sensitive to the quality of what it gets.
Water · Arid Rajasthan, India
Cumin is grown on sandy soils in India’s driest farming districts, where irrigation water is scarce. In a three-year trial at the national seed-spice research centre in Ajmer, drip irrigation used between about 20 and 58 per cent less water over the season than flooding the field, and the least sparing of the drip treatments also gave the highest seed yield, about 830 kg a hectare, and a higher oil content than surface irrigation. The saving depends on equipment: the authors themselves note that the cost of installing drip lines is a barrier for smallholders, and that salty water, common in arid districts, clogs the emitters.
Crop resilience · Northern Transversal Strip, Guatemala
Guatemala’s cardamom descends from seed brought from India between 1910 and 1914 and first planted near Cobán in Alta Verapaz. A century on the country is the leading exporter, with roughly 169,000 ha under the crop and more than 350,000 families depending on it. A genetic survey of 288 plants from the main growing region found low diversity, which its authors attribute to that small founding stock, to growers’ selection, and to two episodes that thinned the crop — outbreaks of cardamom mosaic virus and of the cardamom thrips. An industry built quickly from few plants has less variation to draw on when the next pest arrives; the study also found distinct genetic groups that breeders could use.
How pesticide residue limits work
Why SpiceHQ records a few representative limits rather than a table of all of them.
Pesticide limits are set substance by substance and commodity by commodity, and they change often. In the European Union, Regulation 396/2005 lists the products covered, sets maximum residue levels in its annexes, names substances that need none, and applies 0.01 mg/kg where no level is set. Great Britain has kept that structure since 2021 in an MRL register of its own, with the same 0.01 mg/kg fallback. In the United States, EPA sets tolerances in 40 CFR Part 180, where spices are covered through crop groups such as Spice subgroup 19B and Spice group 26 rather than spice by spice; the azoxystrobin section alone was amended in 2023 and again in 2025. A complete table would be out of date within months, so SpiceHQ records a few representative figures with their dates and instruments, and the rules for reading them, rather than a compliance list.
The representative limits are on the food-safety page, each with its jurisdiction, instrument and date.
Questions this page answers
- how do spices get from farm to shop
- spice supply chain
- what is on a spice certificate of analysis
- what does organic certification mean for spices