During the seedling stages, the plant has clearly de- fined shoot and root parts. Above the soil surface, the shoot is composed of one or more completely devel- oped leaves at the base of which are the primary leaf and upper portions of the coleoptile. Below the soil surface, the root system is composed of the primary root system originating from the seed and the sec- ondary root system originating from the base of the coleoptile. Plants originating from seed placed deep below the soil surface will have extensive mesocotyl and coleoptile elongation compared with plants origi- nating from seed placed on or near the soil surface (Fig. 4-1). Seed placement on the soil surface usually results in no mesocotyl development and little cole- optile elongation. In general, the presence of primary and secondary roots and a shoot, which consists of leaf parts from several leaves, is the basic structure of the rice plant during the seedling stages of growth