116 FIELD CROPS 



ears, while they are known to come from a mother plant of 

 high yielding power, are from an unknown male parent, and 

 many kernels in ears selected from the highest-yielding row 

 have been fertilized by pollen from low-yielding rows. 



154. Pedigreed Varieties. In order that a plant or an 

 animal may be pedigreed, its ancestors on both sides must 

 be known. For a pedigree to be of material value, the 

 performance records of its parents must likewise be known. 

 It is quite evident that it would be impossible to produce a 

 pedigreed variety of corn by the ear-to-row method of breed- 

 ing outlined in the preceding paragraphs. While the mother 

 plant and the record of the mother plant for generations 

 might be known, the male plant is absolutely unknown. 



Pedigreed corn may be produced by starting with the 

 ear-to-row test, selecting 50 to 100 ears as desired. The 

 corresponding number of rows is planted from these ears, 

 but half or less than half of the seed from each ear is used; 

 the other half is reserved for future use. The parts of the 

 ears retained are numbered to correspond with the ears plant- 

 ed. The test is conducted in the same manner as the ear- 

 to-row test. 



The advantage of this method is that after the ear-to- 

 row test has shown which are the high-yielding ears, the 

 best two may be mated by planting the remaining portions 

 of them the following year and a cross between two ears 

 of known high-yielding power thus obtained. For example: 

 If ear No. 25 yields 80 bushels to the acre and ear No. 42 

 yields 85 bushels, while the rest of the ears in the test yield 

 70 bushels or less, it is plain that ears 25 and 42 are the 

 highest yielding ears of the lot. The second year, the re- 

 maining portions of these two ears are planted in an isolated 

 seed plat, alternate rows being planted with seed from the 

 two ears. When the corn in this plat begins to tassel, all 

 the plants coming from one of the ears are detasseled and 



