PLANT BREEDING 423 



their own ears, and seed ears should be saved only from the 

 detasseled rows. 



(4) The continuation during subsequent seasons of the 

 process of seed growing from the best plants obtained in (3). 



In beginning to breed corn it is better to use seed obtained 

 from the locality in which the experiment is to be made. 

 That grown under decidedly different conditions may not 

 succeed. If high- or low-oil corn or high- or low-protein corn 

 is desired, the ears used for seed must be carefully chosen 

 with reference to the development of the horn-like endosperm 

 or of the embryo (Figs. 333 and 334). Selection in the field, 

 as mentioned in (2), is necessary in order to insure that the 

 ears chosen grew on vigorous plants, and that ears from the 

 same plant are kept together. If detasseling is not thoroughly 

 carried out, much self-pollination and self-fertilization is sure 

 to occur. Corn which is self -fertilized produces smaller and 

 less vigorous plants the next season than cross-fertilized corn 

 (Fig. 337). Detasseling has, therefore, been found to increase 

 the yield of corn more than ten bushels per acre. 1 



387. Williams's method. The method of corn breeding as 

 at>ove outlined has been criticized on the ground that little or 

 no attention is paid to the productiveness of the plant used 

 as the source of pollen. A new sys.tem devised by Professor 

 C. G. Williams, of the Ohio Agricultural Experiment Station, 

 provides for equally careful selection of the staminate and of 

 the pistillate parent. The system in its barest outlines, as 

 stated by Professor Williams, provides for : 



1. The usual ear-row test. Only a portion (usually about one half) 

 of each ear is planted. The remnant is carefully saved, and when the 

 ear-row test has shown which ears are superior, recourse is had to the 

 remnants to perpetuate these ears. 



2. An isolated breeding plot in which are planted the four or five 

 best ears as demonstrated by 1. Not the progeny of the best ears, but 



1 For details about corn breeding see De Vries, Plant Breeding, Open 

 Court Publishing Co., Chicago; Bulletin 100, Illinois Agricultural Experi- 

 ment Station ; and Circular 66, Ohio Agricultural Experiment Station. 



