CLONAL ROOTSTOCKS FOR THE APPLE 7 



seem to be variable. More experience is necessary before we can feel sure of the 

 productive capacity of the different types. 



Good stock beds will usually yield from 15,000 to 30,000 rooted layers per 

 acre per year. Higher yields are possible with productive rootstocks and lower 

 yields are by no means rare. The severe cutting necessary is hard on the plants 

 and some, failing to make new shoots, may die. Vacant spaces may be filled in 

 by setting new plants or laying down vigorous shoots. Plants that have been 

 lined out for a year or two are preferable for replacements. 



Plants from stool beds are lined out in the nursery row, managed, and budded 

 like seedlings. They are not often grafted. Most varieties grow as well on 

 clonal roots as they do on seedling roots, though on the very dwarfing clonal 

 stocks they are sometimes a little stockier and have shorter internodes. The 

 dwarfing effect does not become striking until the trees begin to bear. 



In budding seedlings, one finds that the bark of some individuals does not slip 

 well and it is difficult to insert the bud; failure of the bud is more frequent in 

 such cases. Clonal stocks are more uniform in this respect. Some of the more 

 dwarfing stocks mature earlier than do the vigorous stocks and budding these 

 must not be delayed. 



If trees budded on clonal rootstocks are planted in the orchard so that the base 

 of the growth from the bud is surrounded by moist soil, the scion will send out 

 roots. If a dwarfing stock has been used, these scion roots will prevail, and 

 sooner or later the tree will be on its own roots instead of on the dwarfing roots. 

 Thus the stock effect is lost. It follows that trees on clonal stocks should be 

 budded higher than is the usual practice of nurserymen. It is desirable to bud 

 trees on clonal stocks 4 to 6 inches above the ground and plant them in the orchard 

 so that the union between scion and stock can be plainly seen. It has been shown 

 that high budded trees grow as well as low budded trees, or better. A possible 

 objection to high budding is that more of the rootstock may be exposed to winter 

 injury, but scion rooting is a greater evil. In orchard operations, great care is 

 taken never to allow the soil to be heaped around the base so as to give oppor- 

 tunity for the scion to send out roots. 



CLONAL STOCKS IN THE ORCHARD 



The performance of our many varieties on the various clonal rootstocks pre- 

 sents a complicated problem. Not enough is yet known to warrant complete 

 and accurate statements; consequently, only a few generalizations will be at- 

 tempted here. There are very few, if any, varieties that will fail to grow and bear 

 fruit when budded on any of the Mailing rootstocks. However, not all combina- 

 tions are equally satisfactory. Conversely, a given rootstock controls different 

 varieties in different degrees. Mailing IX, for example, does not dwarf all 

 varieties to the same extent. Soil and other environmental conditions often 

 control the growth and fruiting more than the rootstock. Therefore, environ- 

 mental influences are most important and may account for many of the ap- 

 parently contradictory reports on various stock-scion combinations. The fruit 

 of trees on dwarf rootstocks is like that of the same varieties on seedling stocks; 

 often it is better colored and larger on young trees. With increasing age, the 

 apples tend to be small unless the vigor of the tree is maintained and the fruit 

 properly thinned. This leads to the suggestion that dwarf trees do not endure 

 unfavorable conditions as well as those on the usual seedling roots. 



Cultural management and pruning should be much the same as for standard / 



trees except that dwarf trees may require somewhat higher fertility. They / 



