Jan. io, 1914 
Some Diseases of Pecans 
315 
to i mm. in diameter, but no spore formation had as yet occurred. After two months 
the spots were well scattered over the inoculated areas, and some of them had at¬ 
tained a diameter of 10 mm. The pale tawny coni dial tufts were at this time very 
abundant on the upper surface. No infection had taken place on the check tree. 
After three months many of the smaller spots had coalesced to form reddish brown 
areas up to 20 mm. in diameter. 
Experiment No. 3 (Apr. 29, 1912).—The tender leaves of two seedlings were 
inoculated on both surfaces from 5-weeks-old com-meal-agar cultures (strain 33). 
These and the two check trees were left under bell jars for six days, the leaves being 
sprinkled on the second and fourth days. At 10 days infection was just becoming 
evident, while at the end of one month all but one of the inoculated leaves were 
peppered with the more or less angular reddish brown spots. After six weeks the 
development of conidial tufts began to take place on the upper leaf surfaces. 
Experiment No. 4 (May 28, 1912).—The tender leaves of two seedlings were inocu¬ 
lated on the lower surface from a month-old synthetic-agar culture (strain 33) and 
these, with the single check tree, were covered with bell jars for six days. Observa¬ 
tions after three weeks showed the typical spots of this disease up to 3 and in one 
case 6 mm. in diameter. The conidial tufts were just beginning to form. No in¬ 
fection occurred on the check tree. 
Experiment No. 5 (May 29, 1912).—The young leaves of two seedlings were inocu¬ 
lated from a month-old culture (strain 33) on sterile pecan wood, and the tree was 
left under a bell jar for several days. At the end of one month numerous somewhat 
angular reddish brown spots were evident on all the leaves, and these varied in size 
from mere specks to areas 10 or 15 mm. in diameter. After six weeks the development 
of conidial tufts had commenced. No infection occurred on the single check tree. 
Experiment No. 6 (June 7, 1912).—The rather mature leaves of two seedlings were 
inoculated on both surfaces from a 4-weeks-old synthetic-agar culture (strain 113, an 
isolation from the artificially infected leaves described in experiment No. 1). The 
air was hot and dry at this time, and hence the bell jars were left over these trees and 
the three checks for eight days. Observations at the end of two weeks showed the 
development of typical spots on all the inoculated leaves, and at one month the 
formation of conidial tufts had begun. 
Experiment No. 7 (3 p. m., May 23, 1912).—The tender leaves of a young tree of 
the Schley variety at Arlington Farm, Virginia, were inoculated on both surfaces 
from a 4-weeks-old prune-agar culture (strain 33). The day was cloudy, but the hot, 
dry weather of the following week prevented infection. 
Experiment No. 8 (2.30 p. m., June 7, 1912).—A second young Schley pecan tree 
at Arlington Farm was inoculated from a 4-weeks-old synthetic-agar culture (strain 
113). The day was cloudy, and the leaves were covered with moistened cotton to 
further insure the growth of the fungus. The weather was rather hot and dry for 
several days afterwards, but this period was followed by a day or so of rain. Eater 
observations showed a moderate number of the typical spots on the inoculated leaves, 
while the check leaves showed no signs of the disease. 
Experiment No. 9 (3 p. m., June 15, 1912).—In a similar manner the four to six 
young shoots of three Schley pecan trees at Arlington Farm were inoculated from 
6-weeks-old corn-meal flask cultures (strain 33). In this case the shoots on one inocu¬ 
lated and one check tree were covered by heavy paraffined paper bags containing 
moist blotting paper to insure a high humidity around the inoculated leaves, while 
those on one check and two inoculated trees were left uncovered. Showers occurred 
on the two following days. Examination in the fall showed many of the typical spots 
developed on the inoculated leaves covered by the bags and on those of one tree left 
uncovered. There was no infection on any of the check trees. 
Experiment No. io (June 15, 1912).—The young leaves of one potted seedling and 
the mature leaves of another were inoculated from a 6-weeks-old corn-meal flask 
