10 
BULLETIN 1102, U. S. DEPARTMENT OF AGRICULTURE. 
suit of this series was that 1 produced bacteria, 7 grew fungi, and 40 
were sterile. 
Curtis nuts sent to the writer from Blackshear, Ga., constituted 
the last series cultured. Of 88 spots that were plated, eight grew 
bacterial colonies, 20 grew fungi and 60 spots produced no growth. 
The record of these laboratory cultures is shown in Table 2. 
Tabu-: 2. — Record of laboratory cultures of the kernel spots of three rarictics of 
pecans, in November and December, 1921. 
Date cultured, 
1921. 
Culture media. 
Variety and 
source. 
Num- 
ber of 
cul- 
tures. 
Num- 
ber 
with 
bacter- 
ia. 
Num- 
ber 
with 
fungi. 
Num- 
ber 
sterile. 
Date of final 
examination. 
Nov. 30 
Beef agar 
Curtis from cages.. 
do 
do 
Curtis not caged... 
Schley from cases. 
do 
do 
Curtis, Blackshear, 
Ga. 
Frotscher, 
Thomasvillc, 
Ga. 
Schlev, Thomas- 
villc, Ga. 
Curtis, Blackshear, 
Ga. 
17 
26 
15 
65 
60 
51 
25 
25 
21 
48 
G3 
14 
18 
3 
28 
6 

2 
2 

1 
6 
1 
6 
12 
9 
3 
3 
1 
3 
9 
7 
17 
2 
2 

28 
51 
48 
22 
20 
12 
40 
40 
Dec. 6. 
Dec. 1 
. ...do 
Do. 
Dec. 2 
Corn-meal agar 
Beef agar 
Corn-meal agar 
do 
do 
do 
do 
do 
do 
Dec. 7. 
Do 
Dec. 10 
Do. 
Dec. 20. 
Dec. 12 
Dec. 16 
Dec. 20 
Dec. 23 
Do 
Do 
Do. 
Do. 
Dec. 26. 
Dec. 31. 
DO. 
Do. 
Total 
41G 
80 
71 1 205 
Table 2 indicates that of the 416 kernel spots cultured, 63.7 per 
cent produced neither fungus nor bacterial growth. The spots most 
generally producing growths in cultures were those taken from nuts 
badly injured by many insect punctures. Cultures made from spots 
that were only slightly or not at all discolored internally generally 
proved to be sterile. 
Since no constant form appeared in the cases where organisms did 
develop, it was thought highly improbable that kernel-spot could be 
attributed to any of them, especially since most of the cultures re- 
mained sterile. Nevertheless, for the sake of completeness, from 25 
to 50 inoculations were made in healthy pecan kernels, employing 
each of the different forms isolated. 
After an interval of seven days, at a temperature of about 22° C, 
the kernels were all found to be softening more or less around the 
points of inoculation. None of the inoculations produced the mealy, 
dry spots which characterize pecan kernel-spot. 
Since no form of Coniothyrium was developed from the cultures, 
an attempt was made to develop it from badly affected kernels by 
placing them for several days in a moist chamber. Only negative 
results were produced. 
