AGR 203- Principles of Crop Production

The early husbandman cultivated a limited number of crops, the cereals being the first to be grown in most parts of the world. The same crop was often produced continuously on a field until low yields necessitated a shift to new land. This practice is still common in parts of Africa. A modification of this practice was the introduction of bare fallow every two or three years. The primitive husbandman removed by hand the destructive insects in his fields and appeased the gods or practiced mystic rites to drive away the evil spirits he believed to be the cause of plant diseases. With advancing civilisation, materials such as sulphur, brine, ashes, white-wash, soap and vinegar were applied to plants to suppress diseases or insects attack. Cultivated plants are products of human achievement and discovery which has enable man to provide his food and fiber needs with progressively less labour. The first successful domestication of plants by man has recently been suggested to have occurred in Thailand in Neolithic times. The value of lime, marl, manures, and green manures for the maintenance of soil productivity was recognised 2000 years ago. Books on agriculture written by the Romans about the 1st century A.D. describe the growing of common crops including wheat, barley, clover,