THE ROOT SYSTEMS OF FRUIT PLANTS 601 



Cion rooted trees may prove superior in other localities because 

 of their persistence or spread or depth or other qualities. If experience 

 with grapes is a valid analogy, considerable difference between varieties 

 is these qualities would appear upon investigation, some cion roots 

 proving superior and other inferior. In the one case, then, root grafted 

 trees would be superior, in the other, budded trees, since the seedling 

 roots would average better than the cion roots. In sections with cold 

 winters, particularly sections with scanty snowfall, root grafted trees 

 should be used. 



Double Worked Trees. — There are several possible reasons for double 

 working: (1) a lack of congeniality between stock and cion, (2) need of a 

 trunk and scaffold limbs that are mechanically stronger, (3) the top may 

 be subject to disease or winter injury that is more or less characteristic 

 of the trunk. 



Certain varieties of the pear unite poorly with quince stock though 

 they unite well with pear. Therefore, on the quince is worked a variety 

 that does unite well and into this as a stock is budded the desired variety. 

 Beurre Hardy is used by many nurserymen as the linking variety. 

 Bailey^ recommends Angouleme for the same purpose; Rivers, ^^i jj^ 

 England, found a number of varieties useful, including Beurr^ d'Amanlis. 

 Clairgeau and Seckel are among the varieties said to thrive better when 

 double worked. In California double working is favored for Bartlett 

 on quince roots. ^^^ 



Burbidge^^ mentions another combination in double working: "In soils 

 which do not suit the Quince, but in which the Pear luxuriates, this order may 

 often be reversed by using some good-constituted Pear as the root stock on which 

 to graft the Quince, which again in its turn is worked the following year with 

 the kind of Pear desired to form a fruiting specimen." He also quotes Parkin- 

 son (1629) for another interesting example: "Speaking of the red Nectarine, 

 then the rarest and dearest of all fruit trees, he remarks: 'The other two sorts 

 of red Nectarines must not be immediately grafted on the Plum stock, but upon 

 a branch of an Apricock that hath been formerly grafted on a Plum stock.' " 



The apricot as described by Baltet^- is adjusted to dry sites along 

 the Mediterranean by almond roots. Since the grafts do not take well 

 in direct contact, double working is invoked, using a vigorous peach as 

 the connecting link. The same author states that the Damask plum is 

 sometimes used in France as intermediary between the peach top and 

 Myrobolan roots. ^^ 



Certain varieties of apples are notoriously subject to collar rot. 

 To escape this difficulty they may be worked on another variety that 

 is noted for its resistance. Grimes double worked on Delicious in the 

 nursery is now available. Delicious is said to induce \igorous growth, 

 transforming Bechtel Crab, for example, into a much more satisfactory 



