112 
N. C. AGRICULTURAL EXPERIMENT STATION. 
Experiment 8. To determine the influence of acidity or alkalinity 
of the medium. On December 8, 1906, the fungus was inoculated and 
grown in lettuce agar of various degrees of acidity and alkalinity as 
is shown in the table following. 
TABLE V—SHOWING RELATION OF ACIDITY TO GROWTH. 
Total Growth Is Recorded in Millimeters. 
Drops of Normal 
HcL or NaOH 
Fuller’s 
Scale 
Day 
1st 
2nd 
3rd 
4th 
5th 
6th 
7th 
8th 
9th 
10th 
+20 
+15 
+10 
+40.55 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
+5 
+20.55 
0 
2 
3 
5 
7 
12 
16 
16 
18 
18 
0 
+ .55 
6 
14 
28 
36 
41 
67 
75 
83 
83 
83 
-5 
—19.45 
0 
10 
0 
0 
0 
0 
0 
0 
• 0 
0 
—10 
—39.45 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
—15 
—59.45 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
—20 
—79.45 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
Date--_ - . . 
December, . . 
11 
12 
13 
I 
14 
15 
17 
18 
19 
20 
21 
It is seen that growth was inhibited by + 40.55 and — 19.45 of 
Fuller’s scale. At + 20.55 growth was slow. At + 0.55 occurred the 
maximum growth. 
Experiment 15. To determine the toxicity of various fungicides 
acting directly upon the mycelium. 
Sclerotinia was grown in glass capsules in lettuce broth until a 
vigorous mycelium was obtained. The broth was then poured off 
and the mycelium was washed free of any remaining broth by allowing 
about one litre of sterile water to pass slowly through it by means 
of a small siphon. A small portion of the mycelium, the quantity 
as nearly equal as possible in all cases, was then transferred to the 
poison, the effect of which was to be tested. After ten minutes, one- 
third of this mycelium was removed, rinsed in several changes of 
sterile, distilled water and placed in tubes of sterile lettuce agar to 
test its viability. Other portions of the mycelium were similarly re¬ 
moved at the end of an hour and of twenty-four hours. The tempera¬ 
ture of the poisons when used was approximately 21 degrees. The re¬ 
sults are shown in table VI. 
This experiment shows the inefficiency of a ten minute’s applica¬ 
tion of such fungicides as ammoniacal-copper-carbonate, strong and 
weak Bordeaux, formalin 1 ounce to 1 gallon, and 1 ounce to 2 gallons, 
saturated lime water, and potassium permanganate 1 ounce to 10 gal¬ 
lons, though each of the above is fatal if applied for one hour. 
