Jan. io, 1914 
Some Diseases of Pecans 
325 
were all young com-meal-agar-slant tubes of the same age and bearing the Gloeospo- 
rium stage in abundance. Inoculations were by needle puncture in damp chambers, 
and, with the exception of group A, all were held at 28° to 30° C. for 48 hours; after 
this they were kept at laboratory temperature. Group A was held at laboratory tem¬ 
perature throughout. 
Group A consisted of three Jonathan apples which were inoculated with strain 17, 
isolated from diseased pecan leaves collected at Baconton, Ga., in the fall of 1910. 
Group B consisted of three Jonathan and four Yellow Newtown apples inoculated 
with strain 123, isolated in October, 1912, from diseased nuts from Thomasville, Ga. 
Group C consisted of four Yellow Newtown apples inoculated with strain 125 simi¬ 
larly obtained from diseased nuts collected at Sumter, S. C., in October, 1912. 
Group D consisted of three Yellow Newtown apples inoculated with strain 150, 
obtained in October, 1912, from an apple naturally affected with bitter-rot. 
Group E consisted of six Jonathan and four Yellow Newtown apples treated simi¬ 
larly but not inoculated. 
On the fouth day typical bitter-rot areas had developed in all the inoculated cul¬ 
tures. In group A the spots were 1 to 3 mm., while in B to D they were 3 to 20 mm. in 
diameter. It should be stated that the progress of the tissue decay was somewhat 
more rapid with strains 125 and 123 than with 150, obtained from the apple itself. 
In all cases the pale pinkish white mycelium could be seen protruding in tufts from 
the needle punctures, and the dark-colored fruiting bodies were developing. There 
were conidia evident at this time. The check apples remained sound. (PI. XXXIV, 
fig. A.) 
On the eleventh day the spots had increased considerably in size, many of them 
being 15 to 20 mm. in diameter and becoming confluent. (PI. XXXIV.) Acervuli 
extruding the pink spore masses occurred in dense aggregations over the infected 
tissues, being considerably more abundant, however, in strains 123 and 150 than in 
the other two. No perithecia had developed as yet, and even after six weeks none 
had appeared except on the apples inoculated with strain 123. 
Experiment No. 4 (Mar. 21, 1913.)—Sound Yellow Newtown apples direct from 
cold storage were inoculated as in experiment 3 with two strains of the fungus obtained 
from diseased nuts, one each from the pecan leaf and the apple, and one originally 
from the nut but reisolated from an artificially inoculated apple. 
On the fourth day bitter-rot areas had developed about the needle punctures in the 
case of every strain tested, while the check apples remained perfectly sound. (PI. 
XXXV.) The decaying spots rapidly increased in size, and after eight days the 
formation of acervuli had begun. 
Erom these inoculation tests it would appear that this fungus is para¬ 
sitic on the leaves of the pecan, though usually not actively injurious 
until a certain stage of maturity of the leaves is reached, together with 
favorable conditions of temperature and humidity. Field observations 
also bear out this point. 
The limited inoculation work with the nuts, taken alone, would hardly 
justify very definite conclusions, but as far as they go the experience 
with leaf, inoculations is duplicated. No artificial infection tests have 
been made upon very young nut hulls, but from the field observations 
of the last two seasons no evidence of injury during the early part of 
the season has been obtained. The disease has come to notice only from 
mid-season on until fall. These observations are in line with the sea¬ 
sonal distribution of bitter-rot as it occurs on the apple. 
