26 THE CROWN-GALL AND HAIRY-ROOT OF THE APPLE TREE. 
sets of grafts were made on the same lot of seedling roots—one from 
scions selected from orchard trees 12 years old, the other from year- 
ling nursery stock of the Northwestern Greening variety. These 
were grown in cooperative plats 1 to 8. Table IX, in the appendix, 
gives the results as tabulated each year for three years, a definite 
proportion of the trees being dug each year at the ages of 1, 2, and 3 
years, the trees being selected in a fixed numerical series in the row. 
It will be seen from Table IX that there was an increase of 2.4 per 
cent of crown-gall and of 3.1 per cent of hairy-root in the case of 
trees grown from scions taken from rapidly growing yearling trees in 
the nursery as compared with trees grown from scions of harder wood 
taken from fruiting orchard trees. The difference, however, is more 
than counterbalanced by the increased stand of trees, 7.8 per cent, 
obtained from the scions from yearling trees. It must be concluded 
that the difference, though small, is not in favor of the use of scions 
with softer wood from young and rapidly growing trees. 
No effect from leaving a bud near the lower end of the scion in making 
root grafts.—It has been asserted by some of the older workers in 
nurseries that the increased amount of crown-gall on the union at 
the poimt or lower end of the scion is due to cutting the scions so 
that a bud is left near the lower end. This matter was tested in an 
experiment, with the result that the assertion was found to be 
without facts to support it. 
In this experiment scions from the variety Jonathan were cut in 
two ways: One set was made without a bud at the lower end of the 
scion, another equal set with a bud in close proximity to it. These 
were grafted on healthy seedling roots of the same lot and planted in 
ordinary soil in independent plat 1 (see p. 77). Two lots of one hun- 
dred root grafts of each kind were planted. Of the trees grown from 
grafts with buds on the lower ends of the scions, 19.2 per cent were 
diseased, and of the trees grown from those without buds, 21.1 per 
cent were diseased, showing positively that the bud has no direct 
influence in increasing the amount of disease. 
Experiments comparing American and foreign-grown apple seed- 
lings.—There exists in many localities the opinion that seedlings 
erown from foreign seed are less apt to develop crown-gall and hairy- 
root than those grown from American seed. To test this theory, two 
equally large sets of grafts were prepared, scions from the following 
varieties of trees being used: Maiden Blush, Winesap, Baldwin, 
Yellow Transparent, and Missouri. One set was grafted on seedlings 
grown from apple seed imported from France, the other on seedlings 
of the same grade grown in the same field from American apple seed. 
The grafts were divided into eight equal lots and planted in coopera- 
tive plats 1 to 8. A definite proportion of the trees, selected in a 
186 
