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
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.