Rural Industries Research & Development Corporation

The New Rural Industries
A handbook for Farmers and Investors

Welcome to the CORIANDER AND FUGREEK chapter of RIRDC's major new publication (contents page here) on nearly 100 new rural industries.

Coriander and fenugreek ('new spices')

Introduction

Coriander (Coriandrum sativum) is an annual herb that grows to a height of 30–120 cm. It is believed to have originated in southern Europe and was named after the bedbug emitting the same odour. Coriander is extensively grown in India, the former Soviet States, central Europe, Asia, Morocco and Egypt. Production has also commenced in countries like the United States, Canada and Australia.

There are two products from the coriander plant that are used for human consumption: the fresh green herb and the seed (spice). The seed is the product that will be discussed here. It is an important ingredient of curry powder and is used also as a pickling spice. In addition, the seed can be processed to extract oil that is used in the alcoholic beverage, condiment and perfumery industries.

Coriander seed is broadly divided into two types according to its size. Seed size is also an indication of volatile oil content and suitability for particular end-uses. The larger seed sizes have diameters of 3–5 mm, while the smaller seeds are 1.5–3 mm in diameter.

The large-seeded varieties are generally grown in sub-tropical and temperate countries (Morocco, India and Egypt) and contain low volatile oil content (typically less than 1%). These types are used extensively for grinding and blending. The smaller seeded varieties are grown in the cooler temperate regions (central and eastern Europe). These varieties produce a volatile oil content of between 0.5–2.0% for which they are highly valued for oil production.

Fenugreek (Trigonella foenum-graecum) is one of the earliest spices known to man. Ancient Egyptians used it as a food, medicine and embalming agent. The ripe, dried seeds of a quick growing annual leguminous herb, fenugreek has a strong, pleasant and quite distinctive odour similar to maple. The seed is rich in protein and contains volatile fixed oils.

In India, fenugreek is often used as a cover crop in citrus fruit orchards to take advantage of fenugreek’s nitrogen-fixing qualities. India is the major world producer of fenugreek. The spice is exported as whole seed and in powdered forms, as well as in the form of extracted oil, which is extensively used in perfumery.

Markets and marketing issues

About 90% of the coriander produced in Australia is exported, with the domestic market having only limited growth prospects. The main markets for coriander are India, Southeast Asia, North and South America and Europe.

In 1997, the amount of coriander entering the world market was estimated at 40,000 t traded as whole seed. Prices paid for coriander were in the range $A500–$800/t for seed on a cleaned (ex grader) basis. Seedco advises growers to budget on $A600/t ex grader basis with grading and bagging costs amounting to $A60–$90/t.

Seedco provides seed to growers with the seed production delivered to Seedco marketing pools. Private traders also offer contracts, but prices can be very volatile and subject to production levels in major exporting countries. It should be emphasised that price is directly related to the colour quality of the seed.

In 1997, the amount of fenugreek exported from India was 8100 t and was valued at US$3.03m. This equates to US$374/t for clean and bagged seed. Growers are advised to seek contracts with grain merchants and overseas traders/exporters before planting. At this time, this marketing approach appears the only way that growers will be assured access to overseas markets at prices which provide a reasonable return.

Seedco provides fenugreek seed to growers with the seed production delivered to Seedco marketing pools. Private traders also offer contracts but prices are very volatile and subject to production levels in major exporting countries. The major importers of Indian fenugreek are the United States, Europe and Southeast Asia. A very small but ephemeral market also exists for fenugreek seed used as a green manuring crop.

In southern Australia, fenugreek has been commercially produced for a number of years on a small scale. Whilst the potential exists to increase overall production, this can be achieved only with low base prices—typically around $A250–300/t on farm.

Production requirements

The general Australian production requirements for coriander and fenugreek are as follows:

Coriander is suited to a wide range of soil types, with deep fertile loams being the most favoured in the pH range of approximately 5.0–8.0. Soils prone to waterlogging and soils with high iron contents should be avoided. Coriander is suited to a mediterranean climate with wet cool winters and dry summers. It requires a minimal annual rainfall of 400 mm. In most mediterranean climates, coriander is sown at the same time as wheat.

Fenugreek is suited to a wide range of soil types, with deep fertile loams being the most favoured in the pH range of approximately 6.5–8.0. Soils that are prone to waterlogging and soils with a high aluminium content should be avoided. High clay content soils and hard setting soils reduce seed yield due to poor root penetration. Very acid soils are detrimental to plant growth but plants will tolerate mildly saline soils. Fenugreek is suited to regions that receive a minimum annual rainfall of 500 mm.

Varieties

The coriander typically grown in Russia and central Europe (var. microcarpum) has smaller seed (less than 3 mm) and contains more volatile oil than the oriental variety var. vulgare (greater than 3 mm), which is cultivated for seed and herbage. Varieties that have been commercially grown in southern Australia originate from overseas, as there are no locally bred varieties. The common commercial lines used in Australia are thought to be of Moroccan and Egyptian origin.

There are two well-known Indian varieties of fenugreek. These are ‘Desi’ and ‘Champa’. However, the fenugreek crops grown in Australia are not readily identifiable with any known variety.

Agronomy

Coriander is usually sown during May–June but can be sown as late as July. Seed yield can be reduced from plantings later than July. Treated seed is sown at a rate of 15–20 kg/ha. Optimum row spacing is variable and dependent on whether crops are sown on dryland or irrigated areas. Nitrogen fertiliser is applied as a split dose—as a basal and before flowering.

The ground that is sown to coriander needs to be sprayed with a pre-emergent herbicide. After crop establishment, broadleaf and grass weeds need to be controlled with the herbicides Linuron® and Fusilade®. Weed control is an important issue and needs to be implemented as seed yield and quality (contamination) can be dramatically affected, due to slow growth of plants before flowering.

Fenugreek is sown from mid May to mid June. If the crop is sown later there may be problems of lodging, and seed yield decreases dramatically if the crop is sown later than July. Seed needs to be inoculated with the Trigonella strain of rhizobium. The seed should be sown at a rate of 15–20 kg/ha into a fully prepared seedbed. Once again, row spacing is variable and is dependent on sowing time and likely availability of moisture. Nitrogen fertiliser should be applied before flowering commences and phosphorus should be applied at planting if it is required.

The ground that is sown to fenugreek needs to be treated with a pre-emergent herbicide to control weeds. Once the crop is established, weeds need to be controlled with the use of broad leaf and grass herbicides. These chemicals can be Fusilade® for grasses and 24DB for broad leaf weeds. Weed control is very important as this directly affects seed yield and quality (contamination) at the time of seed processing.

Pest and disease control

No pesticides are registered for use in coriander. Coriander production in Australia has not experienced any major problems from insect pests. However, a few crops have been sprayed to control native budworm.

There are currently two major diseases that affects coriander seed production in Australia—Alternaria alternata and Pseudomonas syringae pv coriandricola.

Alternaria alternata: preventative control of this fungal disease is important, as once this disease becomes evident, seed losses are inevitable. This disease is seed-borne and the best control is to use clean seed lines. This disease is usually transferred from crop to crop. However, it has become common practice to use 2–3 kg/ha of an 800 g/kg mancozeb product at 10% flowering to control Alternaria alternata. Fortnightly to three weekly treatments are applied during the flowering period to protect new growth, especially where irrigation is used.

Pseudomonas syringae pv coriandricola: this is a seed borne, bacterial disease against which there is no commercially available preventative treatment.. Research has not yet identified satisfactory control measures. Growers should use only seed that has been tested for freedom from the disease. Growers should use only seed with infection levels below 0.2%. This disease remains dormant in the plant until ‘stress’ is applied to growing plants (eg. frost, hail damage). Once the disease is evident in irrigated crops, it is suggested that watering cease for 2–4 weeks in an effort to reduce the spread caused by water droplets. The disease can cause total crop loss.

Insect populations in fenugreek need to be monitored throughout the life of the crop to minimise damage and reductions in seed yield. Insects that have the potential to damage plants are: red-legged earth mite; lucerne flea; climbing cutworms; heliothis (Helicoverpa spp.); blue-green aphid, thrip and Rutherglen bug.

Fenugreek production in Australia has not been significantly affected by disease problems. However, it is subject to: powdery mildew (Erisiphe polyoni), blight disease (Cercospora traversiana), Rhizoctonia solani, Fusarium oxysporum (Wilt), and Meloidogyme incognita (root rot).

Harvest, handling, packaging
and postharvest treatment

Harvesting of coriander occurs when all seed bulbs have turned light brown to brown, and the crop is fully mature. Harvesting is undertaken with an open front header, all the while ensuring that the seed bulbs are not smashed and retain their round globular shape. Dryland yields reported by the South Australian Primary Industries Department are 1.1–1.2 t/ha in 450–500 mm rainfall areas while irrigated areas yield 1.8–2.5 t/ha.

No coriander is used in or currently exported from Australia for oil extraction. Nearly all coriander is exported in its whole form and is generally for grinding. Accordingly, all coriander should be free of unmillable materials such as dirt, sticks and stones, and when processed should have a minimum purity of 99.5% (by weight) of whole seed to be acceptable to most buyers.

Whole seed can be packed in woven polypropylene or hessian sacks. Weight of sacks is usually negotiated between the client and seller, as is the quality/type of packaging.

The colour of the whole seed is critical for nearly all markets, with poor colour seeds attracting heavy price penalties or even failure to sell. Good coloured coriander is considered to be very light brown or golden. Poor coloured coriander is usually caused by weather (rain) damage or moisture stress. Weather damaged seed also runs the risk of carrying fungal spores, which are harmful to humans.

With increasing sophistication and demands by overseas markets, growers/sellers of coriander are being required to test spice seeds for contamination and the presence of pathogens such as aflatoxins, and salmonella, coliform and E. coli bacteria.

Fenugreek is harvested when the pods turn brown. The crop is not usually susceptible to shattering and can be harvested with an open front header. Crop lifters are an advantage if the crop lodges or becomes tangled. Expected seed yields are 700–1000 kg/ha for dryland production and for irrigated production 1000–1500 kg/ha.

Like coriander, the colour of the product is important with the preferred seed colour being a light tan/orange. Because nearly all fenugreek is either ground or crushed for the production of molasses to produce a maple syrup substitute, the seed needs to be free of harmful contaminants including unmillable materials. Purity for the spice seed (whole seed) is generally above 99.5%. Packaging and pathology laboratory testing requirements are the same as coriander.

Key contact

Seedco (South Australian Seedgrowers Co-operative Limited)
78 Burbridge Road
Hilton, SA 5033
Phone: (08) 8234 9333
Fax: (08) 8234 6133
Email: seedco@seedco.com.au

Key references

Benson, D., (1997). Coriander—Specialist crop reveals considerable potential. Farming Ahead No. 67, July 1997.

Smallfield, B., (1993). Coriander—Coriandrum sativum. New Zealand Institute for Crop and Food Research Limited. A Crown Research Institute. Crop and Food Research, Broadsheet No. 30, June 1993.

*About the authors