For small grain, drying to 14% moisture (wet basis) is sufficient to inhibit both fungal and respirational activity. The shelf life of certain fruits (most commonly apples) may be extended through controlled atmosphere storage (using reduced atmospheric oxygen) in refrigerated stores. In most instances, the careful control of temperature and relative humidity is sufficient to extend the shelf life of most crop products stored on the farm. Increasing emphasis on quality control and assessment will be facilitated by novel items of equipment including the electronic nose, biosensors, X-ray computer-aided technology (i.e. three dimensional mapping; CAT scan), nuclear magnetic resonance (Figure 9) and chlorophyll fluorescence. The demise of the oxen in American and European agriculture was largely the result of their inability to work harvesting machines. When tractors became available, they could pull harvesting machines with only minor modifications. Nevertheless, horses did not lose their comparative advantage, even in harvesting, for some years.
The extent of adaptive innovation required is best illustrated by patent statistics from the United States, which Evenson (1982) has put together on a regional basis. For other developed countries and the developing world, the investigation of innovation in agricultural machinery has been much less systematic.The contrast between Pakistan and Thailand could hardly be sharper. Thailand’s laissez-faire policy has resulted in the development of indigenous power tillers and small tractors, a wider choice of machinery, and few adverse social consequences. Brazil’s approach has been to encourage mechanization by subsidizing loans for buying machinery.