12 Donald Reddick and V. B. Stewart 



infected trees, in order to avoid any contamination. All the trees were 

 one year from the bud and were on peach stock. They were interplanted 

 in the block of apples so that the whole block was on the quincunx plan 

 with trees ten feet apart in the rows. 



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Is 



A BBBBBBBBBBBBBBBBBB 



B BBBBBBBBB B 



C BBBBCCCCCCCCCECCCC 



D CCCCCECCCC 



E CCCCCCCCCCC CCCCCCC 



F EEEEEEEEEE 



G EEEEEEEEEEEEEEEEEE 



H FFFFFFFFFB 



Figure 3. plan of the peach crown-gall experiment 



Each character represents a tree and indicates the name of the variety according to the following key 

 B, Belle of Georgia; C, Carman; E, Elberta; F, Foster. Bold-face letters represent galled trees; light-face 

 letters represent healthy trees 



A great many of the trees failed to start growth when set, with the result 

 that twenty-eight of the original ninety-eight affected trees were removed 

 the first year. All of the affected trees of the variety Foster succumbed 

 early. This may not be significant, because the original source and the 

 treatment of these trees are not definitely known. From the high per- 

 centage of failures the first summer, it would appear that the crown-gall 

 disease may be a factor in securing a good stand. This could be deter- 

 mined readily, but, unfortunately for the experiment, the crown-gall 

 disease has been very scarce on peaches as well as on apples in New York 

 nurseries since 1910, and doubtless for the same reason. 



The winter of 1911-12 was severe, and winter sun-scald was abundant 

 not only in the experimental block but throughout western New York. 

 The loss from winter injury might be ascribed conveniently to a weakened 

 condition of the trees due to the presence of crown-gall. The record shows, 

 however, that 53 per cent of the healthy trees showed this injury, whereas 

 only 20 per cent of the diseased trees were injured in this way. Further- 

 more, the winter of 1910-11 also was exceedingly severe for fruit trees of 

 all kinds. Nurserymen generally were called on to replace many of the 

 trees set in the spring of 1911. One firm alone replaced 20,000 peach trees 

 out of a season's business of perhaps 300,000 trees. This may mean that 

 two or three times the number replaced actually died, since, as a rule, not 

 many persons demand replacement. For the most part the injury to the 

 experimental trees occurred above the snow line, so that new growth 

 started below the frost canker and above the point of union of scion 

 with stock. Even when the renewal came from below the union, the 

 tree was allowed to stand, since the development of the galls should be 

 approximately the same. 



