Guar

24.05.17

Guar (Cyamopsis tetragonoloba) is a summer-growing, annual grain legume traditionally grown as a vegetable, seed fodder and green manure crop. Guar is not known to exist in the wild and it is believed that the plant originated from an African species imported to India as horse fodder by Arabian traders. Guar is now grown in many parts of the drier tropics and subtropics. It was turned into a gum-producing crop in the United States during World War II.

Overview

Typically, the guar plant is an erect, bushy plant, which can grow up to three metres tall. It has trifoliate leaves up to 10cm long, and white or rose coloured flowers. The pods are straight, hairy, pale green, up to 12cm long and contain 5-12 hard seeds (beans) each. However, the form of the plant can be highly variable. Guar has a deep tap root system that can find moisture deep below the soil surface and makes the plant somewhat drought tolerant.

Commercial interest in guar is centred on the endosperm of the seed, which is ground to produce powdered galactomannan gum, which has a wide range of uses. The gum is used as a thickener and stabiliser in foods such as salad dressings, ice-cream and yoghurt. The gum and the water-soluble resin, extracted from the seeds, are also used in a range of other applications, including paper manufacturing, cosmetics, mining and oil drilling.

Traditionally, guar is most commonly grown in India and Pakistan where 90% of the world’s production takes place. Research in Queensland in the 1970s and 80s demonstrated that guar could be grown in northern Australia, achieving yields of 2.0–3.0t/ha, if certain agronomic criteria were addressed. In the decades since guar was first investigated in Australia, a viable industry has not developed due to genotype variability of available varieties and fluctuating demand by overseas processors for guar grain (or splits) from Australia.

There was renewed interest in guar production in Australia in 2013, largely driven by potential use of guar gum by the developing coal seam gas sector for fracking of new wells. There has been some road-testing of potential varieties and seed increase of prospective varieties, but processing facilities have not been built.

Facts and figures

  • Guar (Cyamopsis tetragonoloba) was first introduced into Australia in 1910 from India but little research was conducted on it as a potential crop until the late 1970s and the 1980s
  • Guar is a multi-purpose plant, which is mostly used as a source of gum derived from the endosperm that makes up 25–30% of the grain
  • The endosperm of the guar seed is processed to produce powdered galactomannan gum, which is used in the food industry, in the manufacture of paper and cosmetics, and in drilling fluids for mining and oil industries
  • Since 2012, there has been interest and preliminary development of a guar industry in Australia to supply guar gum to the coal seam gas industry

Production status

There have been several attempts since the 1970s to establish guar production in Australia. Since 2012, there has been renewed interest with a company from the United States establishing a subsidiary in Australia to recruit farmers to grow guar under contract.

As at 2012, Australia imported about 6,500 tonnes of guar gum, which would require about 24,000 tonnes of guar grain to produce. The average importation for the period 1991–97, was about 2,500 tonnes per year.

India and Pakistan account for over 90% of the world’s production of guar. In the United States, a considerable amount of guar is produced in Texas, though the US is still a net importer of guar splits and gum.

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Map of current and potential growing regions

Uses

Guar is a multi-purpose plant, but is mostly used as a source of galactomannan gum, which comes from the endosperm of the grain. Guar gum is produced for the food ingredient industry, being used as a thickener for soft ice-cream, and a stabiliser for cheese, instant pudding, whipped cream substitutes and salad dressings, as well as a meat binder. Lower grade guar gum also has applications in cloth and paper manufacture, oil-well drilling muds, explosives, ore flotation, and a host of other industrial applications.

A large part of the guar gum production is used in the oil industry. There is significant growth, across the world, for use of guar gum as an ingredient in hydraulic fracturing fluid. The fluid is 97–99% water and sand, and the guar gum aids the transport of sand through fractured rock.

Traditionally, guar grain has been used as a vegetable for human consumption and for cattle feed. The sweet and tender young pods are consumed as a vegetable or snacks in north western and southern India and the mature seeds have been eaten during food shortages. Young pods, fresh or dry forage are used as livestock feeds. The guar crop can also be used as a green manure or cover crop.

Guar meal, the main by-product of guar gum production, is a protein-rich material that may be used as an ingredient in stockfeed. The protein content of the meal is 40–45% of dry matter. The plant is also a good green manure or cover crop, providing an opportunity to improve soil fertility within a cropping regime.

Production Requirements

Growing regions

Ninety per cent of guar produced globally is grown in semi-arid and subtropical areas of the north and north west of India (notably in Rajahstan), and east and south east of Pakistan.

Guar has been investigated as a potential crop for the dry tropical or subtropical regions of northern Australia, growing anywhere above the 23°S latitude.

Trial crops have performed well in central Queensland, on the Atherton Tablelands and Gulf Country of northern Queensland, and in the northern regions of the Northern Territory (Katherine and Douglas–Daly).

Soil type

Optimal soil conditions for guar crops are deep, well-drained sandy loams or sands, with moderate alkalinity (pH 7.5–8.0). Heavier-textured soils, such as alluvial clay and clay loams are also suitable, so long as they are well drained. Although production is possible on heavy clay soils, in wet conditions soil crusting can reduce seedling emergence and waterlogging increases the likelihood of root diseases.

Climate

Guar is a hardy and drought-tolerant plant that is well adapted to arid and semi-arid climates with hot temperatures; but can grow in sub-humid conditions. Drought will stop growth of the plant but the plant sprouts when rain resumes.

The crop grows best under hot conditions, with maximum summer temperatures of 35–40°C. The crop is highly susceptible to frost.

In most of the production areas around the world, guar grows and yields well where mean annual rainfall ranges from 250-800mm. However, intensity of rainfall is important and the crop responds well to short bursts of very heavy monsoon rainfall during the growing season.

Varieties

Most lines are indeterminate, meaning they continue to grow and flower provided growing conditions are suitable. However, some determinate lines have been identified and these should be particularly useful in irrigation production.

Globally, there has been genetic improvement of the guar varieties tested in Australia in the 70s and 80s, however these are not readily available to Australian growers.

Planting and crop management

Guar is considered to be a relatively easy crop to grow. It presents a good option for beef producers in northern Queensland (the grain is 40% meal); and it is a useful rotation option as a summer legume in drier summer cropping systems in southern Queensland and northern New South Wales.

Paddock selection for a guar crop is critical to ensure there is minimal risk of waterlogging and minimal competition from weeds, because as at 2014, there are no herbicides registered for use on guar, in Australia.

Soil temperature should be higher than 20°C at the time of planting to ensure good germination. The preferred planting time for guar in southern Queensland and northern New South Wales is October to late December; for northern Queensland, February; and for the Northern Territory, between mid-December and early January.

The crop can be sown and managed the same way that current summer and winter crops are managed; it can be planted with an air seeder or row crop planter. Guar is a quick growing crop, with about 120 days to maturity.

At sowing, the soil should have a moderate to high level of phosphorus. Because guar is a legume, an inoculant will have to be applied to the seed at planting.

Guar can be grown with supplementary irrigation, however water management is critical as over-watering can result in excessive vegetative growth and reduced grain production, and the plant has no tolerance of waterlogging.

Weeds, pests, and diseases

As a new crop, there are no registered chemical control options for weeds, pests and diseases. Good field selection and preparation, and integrated weed and pest management are recommended for all crops, but are especially important when growing new crops like guar.

Leaf sucking insects such as thrips and leafhoppers can attack young plants. Green vegetable bug and brown bean bug can feed on developing pods and can cause seed damage or pod abortion. Crops grown in central Queensland or under irrigation are at greater risk from these pests.

In Australia, the main diseases of guar are ashy stem blight and root rot, both of which are associated with crops grown on poorly drained soils. In addition, leaf spot thrives under humid conditions.

The management of weeds, pests and diseases should be discussed with an agronomist or advisor before embarking on guar production.

Infrastructure Requirements

Guar can be planted, harvested and handled with machinery and equipment that is used to produce other summer and winter grain crops, i.e. cultivation and sowing machinery, harvester and grain handling equipment such as field bins, augers and silos.

Harvesting & Processing

The pods of guar will go black when it is ready for harvest, which will be about 120 days after sowing. If soil moisture throughout the paddock has been uneven, pods may mature at different rates, which can make it difficult to determine harvest time.

Wet or humid conditions during grain development as well as harvesting at high grain moisture contents can both result in weathering of the grain, reducing the commercial value of the crop. Guar holds its seed relatively well and shattering losses are generally low.

The crop can be harvested with conventional headers using a low drum speed to minimise seed damage. Expected yields for well-managed crops are about 1.0t/ha for dryland crops and 2.5t/ha for irrigated crops.

The grain is released from the pods during harvesting but the grain will require further processing to:

  • remove sticks, stones and any metal that may have contaminated the grain during harvest
  • split the bean, through aggressive milling, so its components (hull, protein and endosperm) are more easily separated
  • sift the protein meal from other components of the grain.

In the new industry structure, it is envisaged that preliminary processing (described above) is carried out on farm using a mobile plant or at a centralised processing point. The meal will remain at the farm and the other components of the grain will be transferred to a specialised mill for dehulling (to remove the hull from the endosperm) and to produce powder from the endosperm to produce guar gum. Further processing of the powder will occur, according to end product specifications.

Markets & Marketing

Since the 1980s, there have been several attempts to develop a guar production industry in Australia. Success has been limited by a lack of suitable varieties and market volatility. Growers were exporting whole and split grain, and prices were subject to the vagaries of supply and demand on the world market and foreign exchange rates.

There is renewed interest and opportunity in guar since the establishment of a company in Australia, which aims to develop a vertically integrated production system. The company will establish contracts with growers, and provide seed and agronomic advice.

The immediate market potential for guar growers appears to be the supply of grain for guar gum production. Australia imported over 6,000 tonnes of guar gum and about 90 tonnes of guar mucilages and thickeners, averaged over three years to 2011–12; suggesting there could be future opportunities for import replacement of existing needs, as well as meeting the growing needs of the coal seam gas industry.

The American oil industry is expected to import 300,000 tonnes of guar gum from India, which is 75% of India’s export total. With shale gas drilling establishing in Argentina, Australia, China and Eastern Europe, the demand for guar gum is expected to grow further, however industry analysts report that oil companies are also working on the development of chemical alternatives to replace guar in the drilling process.

Risks & Regulations

Risks/Challenges
The risks and challenges associated with guar production relate mainly to the potential exposure of participating in a new and developing industry. However, there is demonstrated demand for guar gum in Australia and there is investment in and establishment of processing and procurement systems.

The range of varieties available to growers across northern Australia has not been developed for Australian conditions, and further varietal selection and plant breeding, along with refinement of agronomic management systems, would result in more consistent and better yielding crops.

The impact of insect pests, particularly in northern Australian conditions, is not well understood, and will require close monitoring and good integrated pest management strategies.

For individual growers, location will be a challenge and costs of handling and transport to processing sites should be well understood before growing the crop. There are some production risks in terms of seasonal conditions, especially since guar is better suited to the more marginal cropping regions, where seasonal conditions can be volatile.

Regulatory considerations

There are no regulatory considerations relating specifically to the production of guar in Australia.

Publications

Publications/information

Emerging animal and plant industries: Their value to Australia RIRDC report (2014)

Evaluation of Guar Cultivars in Central and Southern Queensland RIRDC report (2005)

Value Chain & Market Analysis for the Australian Guar Industry RIRDC report (2004)

Other resources

Guar (Cyamopsis tetragonoloba) forage, seed and meal  Feedipedia website. An animal feed resources information system

Guar Alternative field crops manual, on website of Purdue University

Guar trials spread to Douglas Daly News article, ABC Rural, 19 July 2013

Industry Body

There is no industry organisation representing guar growers, even though the Guar Industry Development Association operated for a period from 2002.

Image Gallery

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Guar plant with pods grown at Gilbert River

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Guar crop growing at GeorgeTown

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Opened guar pod showing grain inside