594 FUNDAMENTALS OF FRUIT PRODUCTION 



moulding will cause them to become bleached close to the crown of the stool. 

 Upon being hardened back, shoots that give the best results will be formed. 

 When removing rooted shoots in the winter, leave any that are very small for 

 the following year; also any that are weak and spindly. . . . 



"The cooler and moister districts are the best adapted for the raising of Spy 

 stocks by these two methods (layering and stooling), as the rooting of the shoots 

 is controlled by even moisture during late summer and early autumn. From 

 healthy, old, and well estabhshed stools, and those putting up medium and not 

 over-strong shoots, the best results are obtained. The writer advises that layer- 

 ing and stooling should be worked conjointly." 



The use of Northern Spy stock is mentioned by Wickson^^^ in CaUfornia. 

 Paul C. Stark, however, states that Northern Spy has not proved satisfactory 

 in the central states, as a stock, forming knots on the roots and rooting with 

 some difficulty. 



In the northern central states where seedling roots have proved 

 tender in the colder winters recourse has long been made to an indirect 

 method of securing trees on their own roots. Long cions are wliip grafted 

 on small pieces of seedling roots and planted deep. Roots are formed 

 more or less freely from the underground portion of the cion; since the 

 varieties grown are necessarily hardy the roots seem to share in this 

 hardiness and have proved actually hardier than the average seedling 

 roots. In a short time these cion roots generally outgrow the seedling 

 starter which becomes much reduced in proportion and plays an insig- 

 nificant part in the mature tree. 



Varietal Differe7ices and Contributing Factors. — Varieties differ in the 

 readiness with which they emit roots in this way. Shaw^^" found that 

 some varieties root readily, others only in very niggardly fashion; 

 Baldwin, for example, showing 32 per cent., Ben Davis 51, Sweet Bough 

 98, Delicious 22, Mcintosh 74, Jonathan 11, Grimes 41, Gravenstein 55, 

 Northern Spy 58, Oldenburg 25, Tolman 3, Winesap 34, Wolf River 71, 

 Yellow Bellflower 3, Yellow Transparent 26. He found also that the 

 same variety performs differently from year to year, possibly from 

 internal conditions, possibly from external. Stark reports that Delicious 

 forms cion roots very readily and the roots are aphis resistant. Moore^^^ 

 reports on similar work in Wisconsin. Of the varieties tested Livland 

 Raspberry, Hyslop, McMahon, Pewaukee and Transcendent showed cion 

 roots on 50 per cent, of the trees studied, in the third year. Cion roots 

 are formed more readily in moist soil and, because of this, Moore con- 

 cludes that grafts planted deep form roots more readily. Table 8, 

 reproduced from Moore's report, shows the difference in cion root forma- 

 tion in moist and in dry soil. 



Recent investigations in Iowa show that the formation of cion roots 

 is much accelerated by winding the point of grafting tightly with a 

 copper wire.^^ 



