The marginal subsistence economy in many rural communities does not permit the economic flexibility required for experimentation. Added to this is the entrenched individualism, once necessary for traditional subsistence farming, which results in large and small farmers holding tenaciously to traditional patterns of agriculture. There is deep reluctance to change any component in a time honoured interlocking system of production, transportation and marketing. For the small farmer the inflexible use of traditional agriculture is related to the simple methods used for transporting goods - for example, increasing yields would overtax the limited capacity for carrying goods to the marketplace over rough access roads by traditional animals. Furthermore, although crop diversification is the trend in world agriculture, the viability of new crops is not been adequately demonstrated to farmers, and there is deep apprehension of the risks involved.