ABSTRACT
For the past 50 years, the global trend has been towards the practice of depending upon a few high-yielding crops to increase agricultural production and thus decreasing the variety of crops and plants that contribute to food supplies and other needs. The concentration on high-yielding varieties (HYVs) or hybrids has resulted in a significant reduction in the variety and abundance of crops and uncultivated plants. Further, single management systems and procedures have been employed over vast tracts of land to deal with production (Brookfield et al. 2002). The corollary of this has been the need to increase greatly the applications of agrochemicals, both pesticides and fertilizers, in order to manage the status of the crops. Even reforestation projects have been characterized by stands of single species of trees to facilitate harvesting and meet commercial demands.
