124 FIELD CROPS 



Most of the roots of the wheat plant are usually found in 

 the surface soil, though under favorable conditions they 

 have been known to grow to a depth of 7 feet. 



Like most of the grasses, the stems of wheat are jointed 

 and hollow, except in the variety known as emmer, in which 

 the stems are . more or less pithy. During the early stages of 

 growth, the stems are very short, though the}^ verj^ early 

 develop the entire number of nodes and internodes. For 

 several weeks the plants devote their energies to producing 

 roots and leaves and in developing new stems, or stools. 

 When a good growth of leaves and roots has been developed, 

 the stems shoot up quickly, simply bj^ lengthening the inter- 

 nodes. Stooling is accomplished by buds which develop at the 

 lower nodes into culms. In this way a large number of stems 

 may be produced from one seed, the number being deter- 

 mined by the soil and climatic conditions and the thickness 

 of planting. The stems vary in height from 20 to 50 inches, 

 and in diameter from Ke to f/g inch. 



163. The Leaves. As soon as a kernel of wheat germi- 

 nates, it sends out leaves and roots to enable the plant to 

 live after the supply of food in the seed is exhausted. These 

 first leaves come from the lower joints of the stem, and per- 

 form their work during the early growth of the plant. As 

 the stem grows, the leaves on the upper nodes develop and 

 shade the lower leaves so that they wither and disappear. 

 The leaves of wheat are alternate, one leaf appearing from 

 each joint. The lower part of the leaf, the sheath, clasps 

 the stem nearly the entire length of the internode. The 

 sheath is split open on the side opposite the leaf blade, and 

 at the junction of the sheath and blade is a ligule which 

 clasps the stem lightly. The blades are long and tapering; 

 they vary from 34 to 5^ inch in width, and from 8 to 15 inches 

 in length 



164. The Flowers. The flowers of wheat are arranged in 

 a compact terminal spike. The spike is made up of a num- 



