Department of Experimental Plant-Breeding. Iv 



The results of this study, which has l)eeii conducted by Mr. 

 E. C. Ewing, a graduate student, are in manuscript ready for 

 pubhcation. 



Studies on bud variations. — Another investigation is that of 

 determining the range of bud variations and the uses to which this 

 type of variation can be put in practical breeding. It is, of course, 

 well known that bud reversions occur not uncommonly in hybrids, 

 and that in a number of cases, valuable varieties have been secured 

 by the propagation of such so-called bud variations or bud sports. 

 This type of bud variation is, to be compared with mutations and 

 should be called bud mutations. Smaller Inid variations, which 

 are exceptionally common, are probably of the nature of fluctuating 

 variations in seedlings. 



It has been asserted by a number of experimenters that clonal 

 varieties, such as the varieties of strawberries, carnations, potatoes, 

 and the like, which are regularly propagated by the use of vegeta- 

 tive parts, can be maintained in a high state of efficiency and im- 

 proved by the selection of the propagating stock from the best 

 clonal plants. If this is the case, such improvement would naturally 

 depend upon the selection of bud variations. Many growers of 

 potatoes and many experimenters claim to have secured marked 

 improvement by hill selection, which would again depend on the 

 selection of such bud variations. All of this work, however, has 

 been challenged and in general the majority of the experiments 

 are far from conclusive, so that one is left in doubt as to the 

 truth of this claim. 



In order to determine the extent to which the selection of bud 

 variations may be utilized in plant-breeding, experiments have been 

 started to determine the range of such bud variations in po.ato varie- 

 ties and to determine how far characters can be augmented by the 

 careful selection of such variations. In each case the selections 

 have been started from progeny coming from a single tuber, so 

 that pure tuber lines or strains are being used in each case for the 

 selection. The selections are being made with several varieties to 

 increase and decrease the size of tuber, to increase and decrease 

 the irregularities in the tuber, and to increase and decrease the 

 quantity of the product. Every precaution is being taken to make 

 the experiment conclusive, altho in arranging any experiment the 

 supposed best methods may later be found to be unsatisfactory. 



These experiments were first started in the summer of 1908 and 

 no conclusive results have thus far been obtained. Several yearc 

 will doubtless be required to obtain valuable evidence. 



