380 



A. B. STOUT 



Results of the Self-Pollinations of the 1916 Crop of 

 "Improved Red-Leaved Treviso" 



A total of 103 plants were grown in this crop. All were descended 

 from two plants of the 191 3 crop, and all but two had three generations 

 of parentage known to be self-sterile. The data for the self-pollina- 

 tions made on these plants are given in Table i. Here the plants are 

 grouped, as they were grown, in series according to the immediate 

 parentage. The table gives the total number of heads upon which 

 controlled self-pollinations were made, the number of heads producing 

 no seed, the number of heads with seed, the number of seeds per head, 

 and the percentage of fertility. Frequently birds ate seeds, indicated 

 in the tables by " B," and thus interferred somewhat with the deter- 

 mination of the percentage of fertility. 



The 10 sister plants of Ser. 7 were all self-sterile; of the 19 sister 

 plants of Ser. 8, one was feebly self-fertile; of the 25 plants of Ser. 9, 

 three were self- fertile; of Ser. ip, one of 10 plants was self-fertile; of 

 Ser. II, five out of 19 were self -fertile; and one of the 18 plants of Ser. 12 

 was self-fertile. Of the total 10 1 plants descended from self-sterile 

 parentage, 11 were self-fertile in some degree. With the exception of 

 Ser. 7, one or more self-fertile plants appeared in each series. It may 

 be noted that three self-fertile plants, two of which were rather highly 

 self-fertile, appeared in Ser. 9, which was derived by crossing two 

 sister plants of the previous generation. This series was from a more 

 closely inbred parentage than were the other series. 



The total number of fiower heads pollinated in these series is 1205. 

 As a rule, not less than 10 heads were pollinated on a plant, and in 

 nearly all cases this total includes pollinations made on several dif- 

 ferent days. When it became evident that some plants were self- 

 fertile, special efforts were made to continue self-pollination on them 

 in order to secure an abundance of seed for future progeny. However, 

 as shown in the table, the number of heads pollinated on plants com- 

 pletely self-sterile is also often high. 



The degree of self-fertility, judged by the percentage of flowers 

 setting seed, varied considerably. Most of the self-fertile plants were 

 feebly self-fertile, producing as a rule only a few seed per head in 

 only a few of the heads manipulated. Others, as no. 34 of Ser. 9 and 

 no. 8 of Ser. 10, set seed in every head pollinated, and in numerous 

 heads the numbers were nearly equal or even equal to all that were 



