312 
Journal of Agricultural Research 
Vol. XXIV. No. 4 
PLUM TO MARIANNA PLUM 
Experiment 9.—On June 18, 1920, buds from the rosetted Ma5mard 
plum described in experiment 7 were put into a Marianna plum branch, 
near the base of the tree. By September 18, 1920, one of the diseased 
buds had produced a rosetted shoot 8 inches in length with three branches 
from 3 to 5 inches in length (PI. 8, A). This rosetted Maynard plum 
branch made considerably more growth on the Marianna stock than 
similar buds made on the susceptible Maynard stock, but the growth 
was decidedly rosetted and the leaves were mottled yellowish green. 
The Marianna stock grew vigorously throughout the summer of 1920 and 
showed no external s)ntnptoms of rosette. 
Buds from a healthy Mayflower peach tree were put into the new 
growth of the Marianna stock on which the rosetted Maynard plum 
shoot was growing on September 18, 1920. These peach buds remained 
dormant until the spring of 1921, when two buds grew into healthy 
peach shoots. The Marianna plum branches and the Mayflower peach 
shoots made a vigorous growth during the summer of 1921, which 
showed no S3ntnptoms of rosette. The Maynard plum shoot made some 
growth during the summer of 1921, but at all times it had the charac¬ 
teristic S5niiptoms of rosette. In the spring of 1922 the Marianna plum 
stock and the two Mayflower peach shoots (PI. 8, B) developed normal 
leaves in contrast to the rosetted Maynard plum branch. 
This experiment gave additional evidence that the Marianna plum is 
not susceptible to rosette. It also indicated that the causal entity of 
rosette does not pass from a host, such as the Maynard plum, through 
the tissues of the resistant Marianna plum stock to another susceptible 
host, as the Mayflower peach. 
PEACH TO MAZZARD CHERRY 
Experiment 10.—On June 19, 1920, buds from the rosetted peach 
tree described in experiment 4 were put into a healthy Mazzard cherry 
seedling about i year of age. On the same date buds from a healthy 
Elberta peach tree were put into a near-by Mazzard cherry tree of the same 
age to serve as a control. One of the rosetted buds united with the cherry 
stock and made a very feeble grovvth of rosetted leaves. The healthy 
buds united with the cherry stock but remained dormant. During the 
summer of 1920 the inoculated cherry stock grew slowly as compared 
with the control tree. The leaves of the inoculated tree became yellow¬ 
ish green and the new growth was small and in tufts similar to rosettes 
of peach leaves. The inoculated cherry stock developed leaves from 
both lateral and terminal buds in the spring of 1921, giving the new 
growth a decidedly rosetted appearance, especially at the tips of the 
branches. The control cherry stock produced vigorous new growth from 
the terminal buds. Very little growth was made by the diseased cherry 
tree during the summer of 1921, as shown by the smaller and more 
rolled leaves compared to those of the healthy control tree. The healthy 
Mazzard cherry control tree matured its buds and became dormant dur¬ 
ing the fall of 1921, while the diseased cherry tree attempted to make 
new growth from the terminal buds throughout the winter. By April 
25, 1922, the inoculated tree (PI. 9, A) was much stunted and had the 
appearance of being in an advanced stage of rosette, while the control 
