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Introducing guar – a resilient, versatile crop

Introducing guar – a resilient, versatile crop
Tác giả: Lloyd Phillips
Ngày đăng: 11/09/2018

Long grown in India and Pakistan, and more recently in the US, Australia and other parts of Africa, guar is now being introduced to South African crop farmers as a hardy and high-value legume crop for marginal soils.

Guar beans are far smaller than soya beans. A well-managed dryland guar crop can achieve a 1t/ha to 3t/ha grain yield, while an irrigated crop can achieve a 3t/ha to 4t/ha grain yield. Photo: Lloyd Phillips

Historically grown in Asia as a food and livestock fodder crop, guar (Cyamopsis tetragonoloba), is increasingly grown in other regions for industrial purposes. The guar beans are ground up to produce guar gum, a whitish powder long used in the manufacture of medicine, foods and paper as a thickening agent. More recently, guar gum has become valued as an effective, and reportedly environmentally friendly, agent for separating platinum from ore, and as a replacement for toxic chemicals often used in fracking.

According to the African Guar Gum Corporation (AGGC), which is motivating the widespread commercial growing of guar in South Africa, about seven million hectares of this “hardy, robust, annual legume” are currently grown worldwide. Some 78% of this is bought annually by the US, and this satisfies only 32% of the needs of that country’s fracking operations.

Growing Guar locally

The AGGC, which already has a processing plant for guar and other products in Brits in North West, is in search of existing, or new, farming businesses wanting to diversify their production by growing high-quality guar beans on contract for the processing plant. The guar products are sold both locally and internationally.

“Guar gets a growing price that is constant throughout the season,” says AGGC managing director David Wolstenholme. “Guar requires minimal inputs and if used as a rotational crop the input costs can be lower than R5 000/ha. It grows on marginal lands with very low rainfall, which allows it to be competitive with other rotation crops. It requires less moisture and fertiliser, and responds well to higher temperatures and a minimal spray regime.”

According to Nigel Rudling, a senior agronomist with AGGC, there are two grades of guar grain on which payments to contract growers are calculated. Top-quality guar grain, with a 13% moisture content, currently achieves about R8 000/t to R8 400/t delivered to the Brits processing plant. Guar grain of poorer quality, evidencing the likes of high moisture content and contamination from fungal diseases, currently achieves about R7 400/t, depending on the nature and extent of the poorer quality.

There are three varieties of guar currently being trialled in South Africa; Phyta, Sundown and Charisma. They are sourced from Australia because its southern hemisphere environmental conditions are similar to those of South Africa, and are the precursors to a number of other varities that AGGC plans to import to test for the best yield and quality in each of the country’s production conditions.

Over the 2014/2015 summer season, AGGC had 57 farmers growing guar trials across North West, the western Free State, the Northern Cape, KwaZulu-Natal and Botswana. What has been interesting is that in [parts of] the North West and Free State, where the worst drought in 50 years is being experienced, guar is surviving and will produce a yield, while maize and sunflower crops have completely died,” says Wolstenholme.

Growing conditions

According to Wolstenholme, guar is tolerant of daytime temperatures of 30°C to 40°C, requires about 450mm of water during its 30 days to 145 days pod-producing period – and uses its tap root system to scavenge deeper-lying nutrients left over in the soil from preceding crops. However, guar still requires good crop management practices to achieve optimal yield:

Field selection: Soil pH should be between seven and eight, soils should ideally be medium- to sandy-textured with good sub-soil drainage, and lands should be no higher than 1 200m above sea level.

Weather conditions: Guar cannot tolerate frost, while freezing or wet conditions just before harvesting can turn the grain black, lowering quality and making it more difficult to process.

“Guar pods must dry on the plant before harvesting and can be left like this for some time before harvesting without the pods splitting,” Rudling says.

Trial and error

In order to develop the optimal guar management system that will work in different production environments, Rudling explains, farmers currently growing guar experimentally for the AGGC are simply using trial and error. Henri Goosen is one such farmer, growing the Phyta, Sundown and Charisma varities on his farm near Winterton in KZN.

“I became interested in conducting guar trials because our family farm had experienced a number of consecutive years of drought conditions,” says Goosen. “I was looking for a drought-tolerant legume crop that I could rotate with our primary maize crop.”

Goosen’s first-ever guar crops were planted on 5 December 2014. Even with advice from Rudling, Goosen admits that he has struggled to get to grips with the various aspects of guar production. “Effective weed control was one of the challenges because guar is not resistant to glyphosate-based herbicides. While I gave my guar crops preventative sprays against fungal diseases in the early and mid-growth periods – and these worked well – late summer rains caused the development of some fungal diseases that I wasn’t prepared for.

“In future, I’ll probably also apply a late season fungicide treatment. I still have a lot to learn.” While AGGC has gathered much guar production information from around the world to share with South African farmers, this must still be adapted for local conditions by both the AGGC and farmers.

“We know that with the correct management and production conditions, irrigated guar crops can achieve a yield of 3t/ha to 4t/ha, while dryland guar crops can achieve 1t/ ha to 3t/ha,” says Rudling. Many of the management tools that South African crop farmers use to grow their soya crops will also work for guar production, he says. However, some of these will need to be adapted.

Farmer support and growth

Wolstenholme stresses that the AGGC is determined to make a success of local guar production and processing. To achieve this, the company is growing its network of advisory and support services to all local existing and potential guar farmers to ensure they maximise the yield potential and profitability of their enterprises.

Those growing the crop will also benefit from having guar as a legume in rotation with their primary summer crops. The guar will fix nitrogen into the soil and act as a break crop for pests and diseases of the primary summer crops. “We don’t want farmers to suddenly begin growing guar across their whole farm,” Rudling says. “We only intend guar to be grown on a farm’s marginal soils where other summer grain crops don’t achieve optimal production. A farm’s more productive soils must be left to the primary summer crops.”

According to him, farmers interested in growing guar should start out with a maximum of 30ha so that they can learn as they progress. “If they’re eventually confident enough to want to expand their lands under guar, then they can go ahead.”

Wolstenholme says that the boom in demand for guar products will peak within the next 20 years, especially as countries around the world continue to install fracking operations in order to reduce their reliance on imported crude oil.

Canada, for instance, has given the go-ahead for 38 000 shale gas wells in British Columbia alone. Argentina has the world’s third-largest shale gas reserves – which are still untapped – and many European countries are moving forward with fracking.

“The one certainty is that all these countries want a green, clean solution to any new fracking operations,” says Wolstenholme. “For the 2015/16 season, we’re planning on growing 20 000ha of guar with 300 farmers.” The AGGC is hoping that within the next five to ten years, South African farmers will be suppling its processing facilities with 50 000ha to 70 000ha of guar crops a year.


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