96 SOVTHEEN FIELD CROPS 



(6) In about 4 weeks dig some plants resulting from each 

 depth of planting, making drawings showing the 

 position of the principal roots developed from each 

 depth of planting. 



(2) Carefully dig well-grown or even mature com plants, 

 washing the earth from around the roots. 



(a) At what distance below the surface do most of the 



roots originate ? 



(b) Count and record the number of main roots. 



(c) From how many of the joints or nodes do the true 



roots and brace-roots spring ? 



(3) Make two sketches, one showing 



(a) location of main roots where corn was planted in a 

 furrow and earth subsequently thrown to it, and 



(6) location of main roots on a plant which has not been 

 planted in a trench nor had earth thrown to it. 



Brace-roots. 



(4) On well-grown corn plants or on old corn stalks, examine 

 the brace-roots, noting 



(o) their number ; 



(ft) number of nodes from which they spring ; 



(c) diameter just above the ground, and 



(d) diameter 1 or 2 inches below the surface. 



Stems. 



(5) Examine the bent portion of a number of well-grown corn 

 plants or old corn stalks which have been blown down, and sub- 

 sequently straightened, to discover how the plant effected this 

 bending by growing more rapidly on one side than on the other. 

 Make a sketch of one such uneven node. 



(6) Strip the leaves and leaf-sheaths from a corn stalk and 

 record the length of 



(a) the lowest internode ; 



(6) the internode just below the shank of the lower ear, 

 and 



(c) the length of the internode next to the tassel. 



