GUAR

GUAR (cluster bean)5.5

GUAR:forgotten crop

growing in most marginal conditionsmany modern applications

5.3

Guar - Introduction

• Guar is a drought tolerant annual legume that grows in hot, semiarid regions with sandy soils

• The major world suppliers are India, Pakistan, the United States and smaller acreages in Australia and Africa

• The world demand for Guar increased which lead to introduction of Guar in other countries

Guar - Crop properties

• Guar is an upright course-growing summer annual legume (18-40 inches) (45-100 cm)

• The deep roots reach deep moisture

• Leaves, stem and pods are smooth

• The Guar bean has a large endosperm

• The endosperm contains large amounts of gum which is the marketable product of the plant

Guar – Some examples of use

The gum of Guar forms hydrates rapidly in water into a viscous gel and is therefore used in various products

• In Asia:– Beans for vegetable consumption – Crop for cattle feed– As green manure

• In the United States:– No calorie binding agent

• fi stiffener in soft ice cream– In pharmaceutical industry– In cloth and paper manufacture– Oil well drilling muds

Guar – climate and soil

• Drought resistant

• High toleration of temperature (77 to 95˚F) (25 to 35˚C)

• Grows well under a wide range of soil conditions, but preferably fertile, medium textured and sandy loam soils

• Salinity and alkalinity tolerant

• Soil improving crop

• Fits in crop rotation program (with grain sorghum, small grains or vegetables)

Cultivation - Seed preparation

• Select seeds with same size and colour

• Selected seed must be free from other crop and weed seed

• Select seed from the most recent varieties (New varieties are more resistant to diseases)

• Inoculate the seed before planting with a special guar inoculant (or a cowpea inoculant)

• Plant the seeds in moist soil within 2 hours after inoculation

• The seed bed should be free of weed

Cultivation – Seeding date

• Plant Guar when soil temperature is over 70˚F (21°C)

• Optimum temperature for germination is 86˚F (30°C)

• Essential conditions: – Warm seedbed – Adequate soil moisture– Warm growing weather

Cultivation – Seeding and fertility

• With row crop planter, Guar can be planted in rows from 36 to 40 inches. (90-100 cm)

• Planting depth of 1 to 1.5 inches deep (2.5-4 cm)

• Guar requires a high level of phosphorous (22 to 34 kg of P2O5/ha) and a medium level of potash (45 to 56 lb of K2O/ha)

• Apply fertilizer before planting and below the seed

• Optimum pH value is between pH 7 an pH 8

Guar varieties in USA

• Brooks; (1964); first improved variety. High yielding and resistant to major diseases.

• Hall; later maturing compared to Brooks. Resistant to bacterial blight and Alternaria leaf spot. Best adapted to heavier soil types and higher elevation.

• Mills; Early maturing and also resistant to bacterial blight and Alternaria leaf spot. Lower yields than Hall and Brooks.

• Kinman; (1975) a week earlier in maturity than Hall. Highly resistant to bacterial blight and Alternaria leaf spot.

• Esser; (1975) medium to late in maturity. Better disease tolerance than Brooks.

• Lewis: (1986) Medium to late maturing. Seed yields are approximately 25% higher than Kinman.

Control Measures

Weed controlBecause of the slow growing rate of young Guar plant, weed control is important• Mechanical control:

– Do not seed Guar in fields with Johnson grass and other perennial weeds

– Early land preparation minimizes weed problems• Chemical control:

– Treflan (selective herbicide) can be used to control annual grasses and annual broadleaf weeds

Diseases control• Select disease-resistant varieties and high quality certified seed

to prevent Guar from Alternaria leaf spot (fungal disease) and Bacterial blight (seed-borne disease causing plant losses)

Control of insects and other predators• Guar Midge is the primary insect pest in the Southwest of the

USA. Rainfall or sprinkler irrigation may reduce the midge population

Harvesting

• Seed pods are brown and dry at maturity• To speed up drying and to kill weeds, Gramoxone (paraquat)

can be used• Guar beans can be harvested with a normal grain combine• To clean out foreign materials use a high fan speed• Reels should be set deep enough in the Guar to control stalks

(15 to 30 cm ahead of the cutterbar)• For hay: cut crop when first pods turn brown• For green manure: Guar should be turned under when lower

pods turn brown• For seeds: after harvesting Guar can be used as mulch when it

is plowed under

After harvesting

• Income and production costs vary every year and are also

depending on soil types

• Yields vary from 55 to 360 kg per hectare

• Production costs are between 8 and 16 USD/hectare. (depends on fertilizer usage and other production practices

Situation in Pakistan

• Guar is poor man’s crop• Only a few guar gum processing plants – that are struggling to

survive• Quality issues• Guar processing needs revival and international marketing

effort!

Sources of Pictures

• Sheet 1 – www.niemagazine.com• Sheet 2 - www.plthomas.com/guar.html • Sheet 3 - juniper.tamu.edu/Agronomy/guar_pods.htm• Sheet 4 - http://www.shreevinayakcorp.com/guar-gum.html • Sheet 8 - http://www.guar-tex.com/images/seed.jpg• Sheet 12- http://milksci.unizar.es/bioquimica/temas/azucares/ auxiazucar/cyamopsis.jpg