GROWTH AND NUTRITION 



Sometimes a plantlet is formed at the point of attach- 

 ment of the seed by budding from the main axis, while the 

 latter proceeds upward and forms a new or secondary 

 crown nearer the surface. In fact, the entire cereal plant 

 axis, from the seed upward, is practically equivalent to 

 an underground stem, which will branch and root from 

 any portion bearing a node 

 just beneath the ground. 

 It is by taking advantage 

 of this fact that experi- 

 menters have increased 

 the product from a single 

 seed almost indefinitely, 

 through covering with 

 earth successive portions 

 of a plant as it progresses 

 upward, thus constantly 

 producing new crowns and 

 new stems (Figs. 7 and 8). 



15. Leaves and branch- 

 ing. New branches soon 

 start from the crown, 

 which is virtually the first 

 node of the plant. This is the process known agronomi- 

 cally as tillering, and the branches or tillers, in the case 

 of winter varieties, are practically all started before the 

 beginning of the winter resting period. 



There is much variation in the characters of the seed- 

 ling even between varieties. The leaves of most wheat 

 seedlings, for example, are glabrous or nearly so, but in 

 emmers and einkorn they are very pubescent, which 

 imparts to them a gray green color. Seedling barley 

 plants are readily distinguished from those of other 



FIG. 8. Wheat seedling, showing 

 two different crowns 



