z -jg Q The Cornell Reading-Courses 



two strains that have come from individual plants selected from the same 

 commercial variety. 



Individual selection. — Individual selection is more tedious and more diffi- 

 cult to follow than mass selection; it is to be recommended rather than 

 mass selection, however, although the latter method is better than none. 

 When practicing individual selection the grower chooses good heads on 

 vigorous plants in his field, just as is done in mass selection. 



At least one hundred heads should be selected and each head given a 

 number. The simplest method of numbering is to designate the first head 

 No. i, the second No. 2, and so on. As soon as the heads are thoroughly 

 dried they should be carefully threshed, the seed from each head being 

 kept separate and preserved in manila envelopes out of reach of mice. 



Fig. 106. — Planting head ro-ws on the plant-breeding plats of the Cornell University 



Agricultural Experiment Station 



At planting time thirty seeds, as nearly uniform as possible, should be 

 chosen from each head. These seeds should be planted in rows one foot 

 apart and two inches apart in the rows. The rows must be five feet long 

 in order to accommodate this number cf seeds. Each row should bear 

 the same number as the head from which the seed was taken. The plan 

 that is followed in the planting of small grains on the experiment station 

 farm is shown in Fig. 106. 



In order to determine whether the selected heads are any better than 

 the variety from which they were obtained, it is well to take a mixed lot 

 of seed from the variety that grew on the field from which the heads were 

 selected, and to sow every sixth five-foot row with thirty seeds from this 

 mixed sample, which represents the variety. A plan for sowing these rows, 

 which will here be called " head rows," is shown in Fig. 107. 



During the growing season the rows should be visited occasionally and 

 any differences between them noted. For example, if one row shows a 



