5.5
Guar (Cluster Bean)
GUAR:
forgotten crop
growing in most marginal conditions
many modern applications
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 control
Because 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