33 2 Journal of Agricultural Research voi.i, No.4 
glaucum . In the last two cases the injury was similar in no particular to the 
kernel-spot. 
Experiment No. 3 (May 13, 1912).—Three Petri dishes containing four to eight 
kernels from cured pecans were inoculated by placing macerated pycnidia upon the 
uninjured surfaces. A fourth Petri dish was held as a check. After seven days it 
was noted that infection had taken place at every point of inoculation in the first 
two cultures. In the third, two kernels had become infected with the kernel-spot, 
but the remaining two were entirely softened by bacterial contamination. In the 
check Petri dish two kernels were sound and two were contaminated and softened 
throughout by Botrytis cinerea. In no case was the injury by contamination similar 
to the disease under investigation. 
Experiment No. 4 (Nov. 20, 1912).—Ten kernels of newly harvested pecans were 
inoculated with macerated pycnidia and without abrasion of the surface skin. A 
similar number of kernels were held as checks. After nine days, 8 out of the 10 inocu¬ 
lated kernels had developed the disease. The checks were sound, except for two or 
three kernels which had softened and yellowed throughout from bacterial contami¬ 
nation. 
Experiment No. 5 (Dec. 25, 1912).—Eight to ten partially cured kernels of each of 
the following varieties were inoculated with macerated pycnidia by a slight abrasion 
of the surface: Schley, Curtis, Nelson, Teche, Alley, Pabst, and Van Deman. Check 
kernels of each variety were carried throughout the experiment. Similarly, Teche 
and Van Deman kernels were inoculated with the two strains of yellow bacteria 
(strains 100 and 104). After five days the bacterial inoculations had caused a softening 
of the tissues throughout, but there were no evidences of the kernel spot. The fun¬ 
gous inoculations had in nearly every case taken, and spots typical of the disease both 
externally and internally had developed, regardless of variety. The checks were 
sound, except for an occasional contamination with Botrytis cinerea, which had caused 
a general softening of the tissue. Reisolations of the fungus were made from each of 
the varieties inoculated, and one of these strains was used in the next experiment. 
Experiment No. 6 (Jan. 6, 1913).—Three Petri dishes of partially cured Van Deman 
kernels were inoculated upon the slightly abraded surface with macerated pycnidia 
of the fungus reisolated from artificial inoculation in experiment No. 6. Three dishes 
of kernels were similarly inoculated with a Sphaeropsis obtained from old decaying 
pecan hulls, while two were held as checks. Observations after five days showed 
infection with typical symptoms in every case of inoculation with the kernel-spot 
fungus. The Sphaeropsis had caused a general breakdown and softening of the tissues, 
with slight discoloration, but with no symptoms like the disease in question. The 
checks all remained sound and free from infection of any kind. 
No opportunity for field inoculations has presented itself without the 
accompanying danger of introducing or spreading the disease, and hence 
the infection tests have been entirely confined to the laboratory. How¬ 
ever, the characters of the disease are so definite and the results of the 
inoculation work on kernels in the laboratory have been so largely positive 
that the fungus tested (strain 99 and its reisolation) may now be legiti¬ 
mately regarded as the cause of the kernel-spot. The general disorgani¬ 
zation and moist softening of the tissues brought about by the bacteria 
and by the Sphaeropsis, Botrytis, and Penicillium fungi was entirely 
different in appearance and result from the disease under investigation. 
Individual infections of the latter occur within limited and well-defined 
boundaries and, though giving a pithy consistency to the diseased parts, 
never cause a moist softening of the injured tissue. 
