Apt, iS, 1993 
Peach Rosette, an Infectious Mosaic 
313 
tree (PI. 9, B) showed no symptoms of rosette and had made a vigorous 
growth. 
This experiment indicates that the causal entity of peach rosette may 
be transmitted to Mazzard cherry and may produce symptoms similar to 
but not exactly the same as rosette of the peach. In the case of the 
Mazzard cherry there is evidently some resistance to the causal entity of 
rosette, for the infected cherry tree was alive June i, 1922 (when this 
paper was written), 23 months after showing symptoms of rosette. 
Rosette has also been transmitted to two additional Mazzard cherry 
trees by means of infected peach buds. 
WII^D PLUM TO BITTKR ALMOND 
Expkrim^nT II.—^Through the courtesy of members of the California 
Agricultural Experiment Station, fresh seed of Bitter almond, and 
Texas Seedling almond were obtained and planted in the greenhouse 
on November 24, 1920. During April, 1921, some of the young almond 
trees were transplanted to the nursery. On May 23, 1921, buds from 
a rosetted wild Chickasaw plum (used in experiment 6) were put into 
two Bitter almond seedlings in the nursery. Three uninoculated trees 
of the same variety served as control. The plum buds united with the 
almond stocks and during the summer of 1921, one grew into a rosetted 
shoot about 6 inches long. Almond buds on the stock below the point 
where the rosette plum buds were inserted grew into small rosetted shoots 
which died during the winter. By May 24, 1922, the new growth of this 
inoculated tree was stunted (PI. 10, A), and the leaves were yellowish 
green. The other inoculated tree had shown no marked symptoms of 
rosette at the time this paper was written. The adjoining uninoculated 
trees made a vigorous growth in the spring of 1922 and showed no symp¬ 
toms of rosette. 
This experiment indicates that the Bitter almond is susceptible to 
rosette. 
APRICOT TO BITTER ALMOND AND TEXAS SEEDLING ALMOND 
Experiment 12. —On April 18, 1921, buds from the rosetted Royal 
apricot of experiment 3 were put into one Bitter almond and one Texas 
Seedling almond growing in pots in the greenhouse. The buds united 
with the almond stocks, but made very little growth during the summer 
of 1921. Lateral buds on the two almond stocks, below the points of inoc¬ 
ulation, developed small rosetted shoots indicating that the causal 
entity had been transferred from the rosetted apricot to both Bitter 
almond and Texas Seedling almond. Uninoculated almond trees of the 
two varieties growing in near-by pots remained healthy. In the spring 
of 1922 the inoculated trees became rosetted in all parts; the growth 
was stunted and the leaves were yellowish green. The uninoculated 
trees made a vigorous growth, however, and bore healthy green leaves. 
This experiment proves that both the Bitter almond and the Texas 
Seedling almond are susceptible to rosette. 
almond to peach 
Experiment 13. —On February 2, 1922, buds were taken from the 
rosetted Bitter almond and Texas Seedling almond of experiment 12 
and inserted in healthy peach seedlings growing in pots in the greenhouse. 
