EXERCISE 32 



—crown starch 

 -horny starch 



shoot of embryo 



horny starch 



germ 



— root of embryo 



tip starch 



— - hull 

 ■ — tip cap 



Fig. 35. Physical parts of corn kernel 



A DETAILED STUDY OF THE CORN KERNEL 



Statement. In selecting seed corn it is very important to choose a type which is adapted to the 

 conditions of soil and climate under which the crop is to be grown. 



Object. To determine how near corn kernels conform to the 

 standard and to develop skill in judging seed corn. 



Materials. A small piece of board or a shingle ts inch thick ; ears 

 of show or seed corn ; a sharp knife ; a few small nails. 



Directions, i. Cut notches in the board or shingle into which 

 corn kernels of the proper size and shape for the locality will fit and 

 use this form in measuring the length, breadth, and thickness of 

 kernels from the standard varieties of corn ; from different types of 

 the same variety and from different parts of the same ear. 



2 . Choose a dozen type ears and compare and classify the kernels 

 with respect to uniformity in size, shape, and color; in depth, width, 

 and thickness, using the specifications of the score card as a basis. Compare the germs as to size, 

 shape, plumpness, and color as discussed in the text. Select the type of kernel best suited to rich 

 land with abundant moisture ; the type best adapted to upland or a dry season. With the aid of 

 the teacher and the most successful corn growers of the community choose the type of grains best 

 suited to the soil and climatic conditions of the locality. 



Measure the grains chosen and determine their approximate dimensions. Compare these dimensions 

 with those of grains which are believed to be unsuited to local conditions. Make natural-sized drawings 

 of the desirable kernels and discuss fully their qualifications. Give the reasons for your conclusions. 



3. In consultation with the experienced stockmen of the neighborhood classify the selected corn 

 kernels according to their value as feed for fattening stock, giving in writing the reasons for your 

 classification. Compare in detail the character of 

 the best class of kernels for feeding stock with those 

 which you have chosen as the best for planting. 



Questions. Which part of the ear shows the 

 most uniformity in size and shape of kernel ? How 

 may the size and shape of the kernels planted influ- 

 ence the yield ? Why is a thin kernel undesirable to 

 plant ? What relationship does the size of the germ 



Fig. 36. High and low producing seed grains 



At the left, strong, vigorous grains with well-formed germs; seed 

 of the ear from which these grains were taken yielded 81 bushels to 

 an acre in an ear-row test in Kansas ; at the right, weaker grains of 

 the same variety as at the left ; germs not so well developed ; yield 

 of seed from this ear 51 bushels. 



have to the early growth of the plant ? Why should 

 we grade seed corn before planting it? How is 

 corn usually graded? Should kernels with dark 

 colored or moldy germs be chosen for seed? Give 

 reasons for your answer. Should kernels with small 

 or shriveled germs be chosen? Give reasons. What does a deep, narrow, thin, chaffy kernel indicate 

 as to the nature of the soil and climate required by the type of corn it represents? What does a shal- 

 low, broad, flinty kernel indicate? In what respects will the season affect the type of kernel pro- 

 duced? A dry season; an ideal season; a wet season; a short season or one in which the corn 

 fails to mature fully. How do the seasons affect the feeding value of the grain? 



References. Waters, H. J. Essentials of Agriculture, pp. 140-145- Ginn and Company. Myrick, 

 Herbert. The Book of Corn, pp. 84-85. Orange Judd Company. Dtjggar, J. F. Southern Field Crops, 

 pp. 92-95. The Macmillan Company. Morgan, J. O. Field Crops for the Cotton Belt, pp. 159-160. TheMac- 

 millan Company. 



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