INBREEDING 117 



the other plants left to produce tassels. It is then certain 

 that all the ears on the detasseled rows are fertilized with 

 pollen coming from plants produced from the other ear. The 

 seed saved from the detasseled rows may really be called 

 pedigreed corn; that is, the male parent and its performance 

 record, as well as the mother plant and its record, are defi- 

 nitely known. 



In such a breeding plat, it is necessary to take every pre- 

 caution to prevent the introduction of pollen from any other 

 corn. All the corn produced on the row not detasseled 

 would, of course, be inbred; that is, these ears would nat- 

 urally be fertilized by pollen produced on plants from the 

 same ear. All this corn would be discarded and seed saved 

 only from the detasseled rows. 



155. Inbreeding. One of the difficulties encountered in 

 this plan is the inbreeding which is likely to be brought about 

 by this close selection of corn. This may be overcome by 

 continuing the ear-to-row tests year after year. This plan 

 calls for four separate plats or fields of corn each year. The 

 first plat is devoted to the ear-to-row test. The second plat 

 where the best ears, as shown by the ear-to-row test of the 

 previous year, are mated, is called the breeding plat. The 

 third is termed the multiplication plat, which may be of any 

 size desired. Here the seed produced from the breeding 

 plat of the year before is planted to obtain enough seed for 

 field use. The fourth plat is the regular field of corn, the 

 seed for which comes from the multiplication plat. 



For the ear-to-row test which is conducted each year, 

 some of the best ears are taken from the general field, some 

 from the multiplication plat, and some from the breeding 

 plat. When it is thought that new blood must be brought 

 in from outside, selected ears of the variety with which one 

 is working may be obtained from other farms or other 

 ))reeders. By running all these ears together in the ear- 

 to-row test and then selecting and mating together the high- 



