5.5 guar (cluster bean). guar: forgotten crop growing in most marginal conditions many modern...
TRANSCRIPT
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 MeasuresWeed 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