Cluster bean [cyamopsis tetragonoloba (L.) Taub.], an importantindustrial arid legume: A review

Abstract

Cluster bean is an important legume cultivated mostly on marginal and sub marginal lands of arid and semi-arid regions. Overall, India produces around 80% of global cluster bean production. It is cultivated on more than 4 m ha in India, Rajasthan alone accounts for around 80% of the area and production. Owing to its demand in the international market, it has been introduced in the non-traditional growing areas like Andhra Pradesh, Tamil Nadu, Karnataka, Maharashtra and Chhattisgarh. Further, its cultivation is also being taken up under irrigated conditions during summer. Cluster bean seed (endosperm) is a source of a natural hydrocolloid (galactomannan/‘guar gum’). The gum has unique abilities with multiple commercial applications like textile, printing, paper, cosmetics, mining, pharmaceutical, petroleum, natural gas, well drilling and oil industries. Green pods are nutritionally rich and are routinely consumed as vegetable especially in northern and western parts of India. Additionally, cluster bean has been reported to have beneficial effects when cultivated as an intercrop. Cluster bean meal (high protein content) obtained from seed coat and germ cell is an excellent feed for monogastric animals. Cluster bean cultivars with high gum content (>32%) and viscosity (4000-5000 cps) are more preferred for export. The value of cluster bean exports from India has increased from Rs 242 crores (1994) to Rs 2100 crores (2012-13). This review presents the various aspects of cluster bean cultivation and its emergence as an important industrial crop.