136 
N. C. AGRICULTURAL EXPERIMENT STATION. 
bisulphide, and covered with canvas for forty-eight hours, then the 
canvas was removed and the bed left open. No plants were set until 
the odor of the carbon bisulphide in the soil had disappeared. 
At the time of harvesting the crop there had appeared in the bed 
8 diseased plants in a possible 160, which is a slightly smaller per cent, 
than occurred upon the bed that was top dressed one inch deep. While 
this treatment seemed to check the disease somewhat it can not be re¬ 
garded as satisfactory. 
Experiment 10. To determine the effect of formalin 1 part to 400 
parts of water. 
Upon a bed fifteen long formalin of the above strength was sprinkled 
with a watering pot at the rate of one-half gallon to the square foot. 
One-half of this solution was applied at one time and the second half 
two hours later. After sprinkling the bed was left 2 days then stirred 
with a sterile hoe to aid in drying. Two days later the plants were 
set out. At harvest time the plants looked better, were more uniform 
in size, and there were no diseased plants among 160 that the bed 
contained. The treatment looked promising and the experiment was 
repeated at West Raleigh in 1908-09, with the result, however, that 62.5 
per cent, of the plants were affected. 
TABLE XVII.—SHOWING EFFECTS OF SOIL DISINFECTION. 
Method 
Number 
of Plants 
Treated 
Diseased 
Plants in 
Treated Area 
Healthy 
Plants in 
Treated 
Area. 
Per Cent 
of Diseased 
Plants 
Steamed with Drain Tile .. 
1,260 
88 • 
1,172 
6.98 
Steamed with Sargent Sterilizer. 
696 
33 
663 
4.80 
Top Dressed with 1 in. Disinfected Soil. 
320 
21 
299 
7.02 
Top Dressed with 2 ins Disinfected SoiL ... 
% 
320 
16 
304 
5.26 
Top Dressed with 3 ins. Disinfected Soil_ 
320 
12 
308 
3.89 
Sprinkled with Carbon Bisulphide... 
160 
8 
152 
5.00 
Sprinkled with Formalin at New Bern. 
160 
160 
Sprinkled with Formalin at West Raleigh_ 
144 
'90 
54 
62.50 
Control_ 
1,260 
38 
1.222 
3.02 
From the above experiments in attempts at soil disinfection little 
hope is to be had. Though these means of disinfection may apply 
well in green-house conditions, it is obvious that they are not satisfac¬ 
tory in extensive cold frames. Whether some other method of soil 
treatment may not be devised, we can not, of course, say. Theoreti¬ 
cally, it seems possible, but that these means mentioned above are of 
practical service, seems very doubtful. 
Practical Considerations. 
The rational method of eradication of this pest based upon the facts 
here adduced would seem to be the same as that practiced against an 
