30 



MASS. EXPERIMENT STATION BULLETIN 22ii. 



started, as Fig. 1 indicates; for during the years 1923 and 1924 they 

 made more growth than Tolman trees on any other roots. The dif- 

 ficulty lies in getting the Tolman roots started. This was the hardest 

 of any of the varieties to root from the scion, and therefore was under 

 a great handicap when the trees were set. 



The English Paradise stocks have not done as well as Fig. 1 indicates. 

 They made a fairly rapid growth at the start but slowed down very 

 noticeably during 1923 and 1924. The tops are small and in some cases, 

 such as with Tolman, show a very characteristic shape. (See Fig. 5, 

 Plate II.) Notice the flat spreading character of the top. Compare this 

 with the upright growth of Yellow Transparent on the same stock (Fig. 6, 

 Plate II.) 



In regard to tiie effect of the different stocks on bearing, no conclusions 

 can be drawn at the present time as the trees have not borne enough 

 crops to determine what their actual performance will be. Figure 2 

 shows the average total yield for the years 1922, 1923, and 1924. 



This figure shows four things in regard to earliness of bearing. First, 

 the dwarfing stock, English Paradise, brought most of the varieties into 

 earlier fruiting than any of the other' stocks. Second, Oldenburg stocks 

 have not brought any of the varieties into early bearing. This is because 

 the tendency toward late bearing, due to lack of vigor, completely out- 

 weighs the tendency toward early bearing, due to the dwarfing effect. 

 Third, Mcintosh on its own roots has borne earlier than Mcintosh on any 

 other root. This is due to the exceeding vigor of the Mcintosh roots which 

 have brought the tree to bearing maturity more quickly than any other 

 roots. Fourth, the Northern Spy root has had the eft'ect of a dwarfing 

 stock on Mcintosh and brought it into early bearing. As has already been 

 pointed out, the growth records show that this dwarfing effect is not 

 permanent. 



From this work it is concluded that the effect of the stock on the 

 vigor of the scion depends on (1) the vigor of the stock; (2) the readi- 

 ness of rooting of the stock, though this is only temporary; and (3) "the 

 degree of success of union between the stock and scions." 



It follows, then, that a uniform vigorous hardy stock which can be 

 propagated by vegetative means is needed to replace the seedling stock 

 now in use for the propagation of apple trees. This problem has been 

 taken up by the L^nited States Department of Agriculture and the Penn- 

 sylvania Experiment Station, as well as by the Massaciiusetts Experiment 

 Station. 



In the spring of 1924 this Station imported from the experiment station 

 at East Mailing, England, 800 stocks of 17 types. These types had been 

 selected from apple stocks commonly grown on the European continent. 

 They range from very dwarfing stocks to free growing standard stocks, 

 all of which, it is said, can be vegetatively propagated by means of mound 

 layers. Some of these imported stocks were used for increasing the supply, 

 and others were budded to Mcintosh and Wealthy in August, 1924. It is 

 hoped that among these stocks one or more will be found which fills 

 the requirements of a good stock. 



