12 



The writer is of the opinion that systematic economic bud selection work 

 with sugar cane will give particularly early and striking results in the way of 

 improved sugar production per acre, which will be worth millions of dollars 

 annually to the industry. 



The simple elimination through bud selection of some of the undesirable 

 strains arising from bud mutations in the established varieties will in itself 

 achieve this result. This work can be carried on without any possibility of loss 

 to the industry or the rearrangement of any of the methods of culture other than 

 that of securing seed cane for planting. The cost of this work will be very 

 small in comparison with its value. The increased production of sugar through 

 the culture of uniform and superior varieties will be effected at no greater cost 

 than that previously sustained when growing the more variable varieties with 

 their resulting lower yields. 



In pineapples, the writer observed in May, 1920, amongst the plants in a 

 commercial field of the Smooth Cayenne variety grown on the Island of Oahu, 

 T. H., many apparent striking bud mutations. The leaves of some plants were 

 smooth while others were sharply serrate. The shape of some of the fruits was 

 cylindrical, while in other cases it was pyriform, ovate, obovate, globular, or 

 modifications of these shapes. About 25 per cent of the plants had no fruits, 

 while others were bearing fruits of different stages of ripeness. Some of the 

 plants observed possessed a single crown, while others had multiple crowns. 

 Frequent examples of plants having distinct strain characteristics, apparently 

 originating as bud mutations, were found, indicating that bud variation is of 

 common occurrence in this variety. 



The above list of varieties arising from bud mutations contains only a few 

 of those on record. Furthermore, the recorded instances constitute only a small 

 part of the total number of such cases. This condition exists to a large extent 

 because most observers have not realized the possibility of the occurrence of bud 

 mutations and their relation to the production of new varieties. For this reason 

 it has been quite generally believed that bud varieties are fixed, and any new 

 forms discovered in them have usually been ascribed to seed origin. Enough 

 instances have been given to prove the importance of bud mutations in plant 

 improvement work, and particularly so in the case of those plants which are 

 vegetatively propagated. 



THE ISOLATION OF STRAINS IN ESTABLISHED VARIETIES. 



The term strain as here used designates a group of individuals of an agri- 

 cultural variety differing from all other individuals of the variety in one or more 

 constant and recognizable characteristics and capable of perpetuation. This dis- 

 cussion will be largely confined to vegetatively propagated strains which in scien- 

 tific literature are frequently referred to as clones, as suggested by Webber (76). 



Strains oftentimes arise from the unintentional propagation of bud muta- 

 tions. For example, the writer and his associates have found in their study of 

 the Washington Navel orange (64) that this variety as grown under California 

 conditions has given rise to fourteen strains through bud mutation within a few 



