Crown-Gall of Apple and Peach 11 



disappeared, and judging by this test the crown-gall disease on apples 

 seems, in this locality, to be chiefly a matter of concern to the nurseryman. 



Even in the nursery it is not certain that the disease is of great conse- 

 quence for apples. It will be noted that most of the trees used in the test 

 were of a size to be graded first-class. Galled nursery trees have been 

 seen that were short and very small in diameter, and the natural inference 

 is that the presence of the disease accounted for the size of the tree. It is 

 to be remembered, however, that trees of small caliper are not uncommon 

 in the nursery even when no disease is present. Tree C-6 of the experi- 

 ment is of this sort, and its behaviour when planted in the orchard is of 

 particular interest. Two companion trees of C-6 were rejected for the 

 experiment because their dwarfed condition obviously made them unfair 

 to the test. One of the writers (R) planted these two trees in deep sandy 

 loam on private land. Both trees have made excellent growth, and as 

 they were top-worked to early-maturing varieties both have borne crops 

 of fruit. One tree was removed in 1922 to make way for a building. 

 There was no evidence of the original gall or of subsequent infection. 

 The other tree is larger than some others that were set in the immediate 

 vicinity two years earlier. 



In connection with the outcome of this experiment the experience of a 

 well-known horticulturist is of interest. The following extract is taken 

 from an article by C. A. Green, for many years editor of Green's Fruit 

 Grower. The article appeared in the issue of that journal for May, 1912. 

 The orchard mentioned in the article is located twelve miles southwest 

 of Rochester, New York, and is of special interest because it is in the main 

 apple belt of western New York. 



Here is something that I want to call particular attention to. There is much said in these 

 days about root gall on apple trees. At the time I planted this orchard but little was known 

 about root gall. As I planted the trees with my own hands I noticed that occasionally 

 a tree had a knotty excrescence on the roots which I now would recognize as root gall, and 

 which is now regarded as infectious and fatal to the growth or welfare of the trees. Here 

 is an interesting point which I desire to allude to: after growing for over thirty years and 

 bearing fruit abundantly for over fifteen years, every tree in this orchard is healthy and 

 one tree is as productive as another, and yet a number of these trees were infested with root 

 gall. If the views of the experiment station are correct, the trees I planted thirty years ago, 

 which were then affected with root gall, should long ago have perished or should have shown 

 some signs of disease. That the trees are now all healthy and productive, teaches me that 

 we have something yet to learn about root gall oh apple trees. 



THE EXPERIMENT WITH PEACHES 



In the spring of 1911 a quantity of peach trees bearing evident lesions 

 of crown-gall were procured from New York nurserymen. On April 6, 

 1911. photographs were made and the trees were set in the diseased garden 

 as indicated in figure 3. Healthy trees were obtained in a separate ship- 

 ment. The healthy trees were prepared for planting by one man, who used 

 all antiseptic precautions. They were planted before the general lot of 



