Potato Failures. 
33 
gated but twice. The runs were only about four inches deep, making it im¬ 
possible to supply the water properly. 
Plat I—Check —These tubers were rough and scabby and all of them 
were more or less covered with the hyphae and sclerotia of Corticium. The 
plants came up very unevenly and 32% of this seed failed to produce plants 
which reached the surface of the ground, Seventeen per cent, of those that 
grew, developed small worthless tubers. Only 57% of the seed planted 
produced plants which developed large tubers, and these were scabby and 
of a poor quality. On July 24th the plants in this plat were carefully exam¬ 
ined and it was observed that 55% of the plants had their main stems cov¬ 
ered with the fruitage stage of this fungus. Three hundred and twenty-five 
pounds of seed gave a return of 1,240 pounds of tubers. A yield of 3% 
pounds of tubers for every pound of seed planted. A return of 23 sacks to 
the acre. 
Plat II —This seed, like that used in the Check plat, was scabby and 
more or less covered with the hyphae and sclerotia. It was treated with 
corrosive sublimate, standard strength, seven days before it was planted. 
These plants were about eight days later than those of the Check plat and 
they also came up very unevenly. Twenty-six per cent, of the seed failed 
to produce plants which reached the surface of the ground. Ten per cent, 
of those that grew failed to develop large tubers. Only 67% of the seed 
planted developed salable tubers. They were clean and quite free from 
scab. Fifteen per cent, of the plants in this lot showed traces of the fruit¬ 
ing stage. Two hundred pounds of seed gave a return of 1,080 pounds of 
tubers. A return of 5% pounds of seed for every pound of seed planted. 
Giving a gain of 41% over Check, or about 32 sacks to the acre. 
Plat III —This seed was carfeully selected. All tubers containing sclero¬ 
tia were rejected. However, many of these were rough and scabby, and 
all of them were more or less covered with the hyphae. These plants also 
name up very unevenly. Seventeen per cent, of the seed planted failed to 
produce plants which reached the surface of the ground. Twenty-eight per 
cent, of those that reached the surface failed to develop normal tubers. 
Seventy per cent, of this seed produced plants which developed fair-sized 
tubers. These tubers were rough and more or less covered with both hy¬ 
phae and sclerotia. Twenty per cent, of the plants showed traces of the 
fruiting stage. One hundred and fifteen pounds of seed produced 497 pounds 
of tubers. A return of 4 8-25 pounds for every pound of seed planted. 
The yield being nearly the same as that of the Check. 
Results. —1. Diseased tubers are frequently prominent factors in pro¬ 
ducing crop failures. 
2. The fruiting stage of this fungus apparently develops more freely 
on plants grown from tubers containing many sclerotia. 
3. Carefully selecting seed free from sclerotia, but more or less covered 
with the hyphae of this fungus did not check its injuries to any marked ex¬ 
tent, but the fruiting stage of the fungus developed less freely on the plants 
from the selected seed. 
4. The standard corrosive sublimate treatment apparently checks the 
development of this disease when the treated seed is planted in new soil. 
<D 
£ 
cj 
r—I 
C8 
I. 
TABLE XI., SHOWING RESULTS OF EXPERIMENT NO. XI. 
TREATMENT 
Number Pounds 
of Seed Tubers 
Planted 
Total Number 
Pounds of Tubers 
Harvested 
Yield for Every 
Pound of Seed 
Planted 
Gain 
Check . _ 
325 
1240 
3.81 
Treated, Corrosive Sublimate 1 oz. to 8 gals, of water, 1>£ hrs. 
2C0 
1080 
5.40 
41$ 
Selected free from Sclerotia-- - - 
115 
497 
4.32 
13$ 
o 
cti ® 
• i—i 
T3 ® 
23 
32 
26 
