CLONAL ROOTSTOCKS FOR THE APPLE 17 



Semi-Dwarfing Rootstocks 



The semi-dwarfing Mailing rootstocks are not alike in their dwarfing influence, 

 but there is not ver}' good agreement on the dwarfing efl^ect of the several stocks. 

 Trees on these stocks may be expected to grow from one-half to two-thirds the 

 size of standard trees of the same variety. They will rarely exceed 15 to 20 

 feet in height at maturity and do not require as wide spacing. For these reasons, 

 they have attracted the attention of fruit growers who dislike tall trees. They 

 should be planted from 20 to 35 feet apart according to variety and soil. They 

 may be planted and handled in exactly the same way as standard trees except 

 that the union must be above ground and they may require a little higher fer- 

 tility. They are suitable for fillers when one desires to plant an orchard on this 

 system. Thus, an entire row may be planted with one variety, which simplifies 

 orchard management. 



There are 7 semi-dwarfing rootstocks, and it seems wise to introduce only the 

 best ones. Mailing III sprouts from the stock more freely than the others and 

 this habit is a nuisance. It is hardy and reproduces well in the stock bed. Mailing 

 VI does not reproduce very well and seems to have no superiority in other re- 

 spects. The other semi-dwarfing rootstocks are all good. Doubtless further 

 experience will show that some are not as satisfactory as others at least for some 

 varieties. We are inclined to favor I, II, IV, and VII as the semi-dwarfing stocks 

 most likely to prove valuable and it would simplify matters if this list could be 

 shortened. A large number of rootstocks complicates matters and increases the 

 chances of mixtures. 



Standard and Near Standard Rootstocks 



The standard and near standard Mailing rootstocks, numbered from X to 

 XVI, produce trees that are much like trees on seedling rootstocks. It is yet a 

 question whether such trees are superior to seedling rooted trees. As has been 

 said, little is to be hoped for in greater uniformity or in eliminating poor trees in 

 the orchard. We do not have Mailing XI and XIV, and thej' have not excited 

 any interest in this country. Mailing XIII seems to be capricious as to soils and 

 some varieties do not succeed well on it, while X and XV seem to have no out- 

 standing qualities. This leaves XII and XVI as the more desirable clonal root- 

 stocks for full-sized trees. Mailing XII is a good stock for all varieties and seems 

 well suited to most of the ornamental crabs, many of which fail on the dwarfing 

 stocks. Mailing XVI reproduces well, although it often does not produce a good 

 root system in the stock bed. It grows and buds well in the nursery and pro- 

 duces satisfactory, large, productive trees for the orchard. We consider it the 

 most desirable of the vigorous Mailing stocks. 



DESCRIPTION AND IDENTIFICATION OF CLONAL ROOTSTOCKS 



With the increasing use of clonal stocks, the problem of keeping the different 

 types pure and true to name becomes more and more important. There seems 

 to be some tendency to regard all clonal stocks as dwarfing; this is not true. 

 With a wider knowledge of the interrelations of stock and scion, the importance 

 of using the proper stocks for various varieties will be greater. Nurserymen and 

 others growing trees on clonal stocks must know what stock they are using and 

 inform their customers. They must, therefore, avoid mixing stocks in the nur- 

 sery row. 



While the different clonal rootstocks can be identified before they are budded, 

 it is difficult and often impossible to tell what stock is under a budded tree either 



