Demand for food has increased exponentially while the availability of arable land for agriculture has decreased, due to increased urbanization and industrial growth. Among various stresses, drought is a major constraint to rain-fed crop production. It is estimated that nearly 3. 7 billion hectares of global land area is affected by drought, which is equal in area to the global drought-free land. There are various perspectives from which we can view drought, but those that impinge upon human and animal life directly by adversely affecting availability of water, agricultural (food/fodder-feed/fibre and medicinal crops) production, ecology and industry are the ones of major concern.