348 POMOLOGY 



for the future. In the prairie section of the northern United 

 States and Canada, one of the serious problems in fruit- 

 growing is the damage done to the roots of the trees by low 

 temperature, and hence it is important to secure stock which 

 is most resistant to cold. 



The first problem is the securing of own-rooted trees. 

 Apples do not root readily from stem-cuttings and this proc- 

 ess cannot be used commercially with the present Imowledge 

 of the subject. Root-cuttings, however, can be planted with 

 success, and the method is employed commercially to some 

 extent. 



The most common process of securing own-rooted trees 

 is by the "long cion — short root" method, also known as the 

 "nurse-root" method. Advantage is taken of the fact that 

 deeply planted root-grafted trees will often send out roots 

 from the cion, and later (after two seasons) the trees are 

 dug and the stock portion removed. There seems to be 

 great variation in the ability of varieties to form roots. 

 Shaw ^ made trials of over 150 different varieties and species 

 to measure their rooting ability. There was a variation of 

 rooting from to practically 100 per cent. A few of those 

 exhibiting a high percentage of rooting are: Arkansas (77), 

 Bailey Sweet (95), Sweet Bough (98), Fameuse (80), Opales- 

 cent (89), Primate (92), and Westfield (83). Some exhibiting 

 a low percentage of rooting may also be cited: Bethel (0), 

 Black GiUiflower (6), Ensee (6), Ingram (2), Jeffris (3), 

 Lady (3), Ortley (2), Paradise Winter Sweet (2), Red Canada 

 (2), Tolman (3), and Yellow Belleflower (3). It cannot be 

 stated at present with much definiteness just what factors 

 influence certain varieties to root freely from cions and 

 others to root very poorly. The following are suggested as 

 entering into the problem: a correlation between hardness 

 of wood and rooting ability, the softer the wood the higher 

 1 Shaw, J. K. Mass. Agr. Exp. Sta. Bull. 190. 1919. 



