IMPROVEMENT OF ROSES BY BUD SELECTION. 101 



It is equally demonstrated that cumulative results are not to be expected 

 by selecting parts showing like tendencies through successive generations. 

 The flowering habit of plants which themselves had been produced from 

 flowering wood was not increased, even in the fifth generation, over what it 

 was in the first. On the other hand, plants repeatedly propagated from blind 

 wood through five successive generations were not markedly less floriferous 

 in the fifth than in the first generation. 



In both plants propagated from blind and from flowering wood, there was 

 a slight tendency towards lessened flower production. This may be accounted 

 for in that the stock from which the plants were propagated each season had 

 been grown and forced under artificial conditions, and no attention was given 

 to selecting cuttings from the strongest plants. The commercial side of this 

 experiment is, of course, the most important one from the standpoint of the 

 practical grower. It is clearly more economical for the florist to produce his 

 plants each season from blind wood, and since there is no cumulative effect 

 from such a procedure, the plants so produced are not necessarily less flori- 

 ferous than the parent stock. But where bloom rather than stock plants is the 

 end sought the tests above recorded are emphatic in declaring the superiority 

 in this respect of plants grown from flowering wood. A rose grower can well 

 afford to send short-stemmed roses to market during the months of January 

 and February, if by so doing he can secure sufficient flowering wood for pro- 

 pagating purposes to insure a stand of flowering wood plants for the pro- 

 duction of the succeeding crop. 



L. H. Bailey: I would like to ask Prof. Corbett about the correlation of the vigor 

 of the plant with the length of flower stem, with the productivity, and also the date of 

 maturity from cuttings, whether one is later than the other, as a rule. 



L. C. Corbett: There was practically no difference as far as the vegetative vigor of 

 the two sets of plants was concerned; one was practically as vigorous as the other. 

 Under the treatment which we gave them they were planted in the same house and 

 grown under substantially the same conditions we could detect no difference in the 

 vegetative vigor of the two sets. I think in nearly every case the flowering plants came 

 into bloom a little earlier than the blind plants, but throughout the five years I could 

 detect practically no difference in the vegetative vigor of the two. 



