28 
Bulletin 91. 
during the summer, and many diseased tubers were found in this plat at 
harvest time. It gave an average yield of 147 sacks of tubers per acre. 
Plat II —This seed also contained many diseased tubers, but it was 
treated with corrosive sublimate one day before planting. The plants were 
five days late in reaching the surface of the ground. A few diseased plants 
were observed in this plat during the summer, but the tubers were clean, 
smooth and free from both scab and sclerotia. This plat gave a return of 
213 sacks of tubers per acre, a gain of 66 sacks per acre. 
Plat III —This seed was treated with corrosive sublimate on December 
9th. After it became thoroughly dry it was again sacked and placed in the 
dugout until May 6th, when it was cut and planted. The plants were a week 
late in reaching the surface of the ground, but they did nicely and no dis¬ 
eased plants were observed in this plat. The tubers were clean, smooth and 
free from both scab and sclerotia. This plat gave a return of 160 sacks of 
tubers per acre, a gain of 13 sacks per acre over check. 
Plat IV —This seed was taken from the dugout on December 9th, and 
treated with corrosive sublimate one hour and then placed on the floor until 
thoroughly dry, when it was sacked and placed in the dugout until May 5th, 
when it was again placed in a solution of corrosive sublimate for one hour. 
It was cut and planted on May 6th. The plants were 8 days late in reaching 
the surface of the ground. They did nicely, however, and no diseased plants 
were observed in this plat. The crop was clean, smooth and free from 
both scab and sclerotia. This plat gave a return of 143 sacks of tubers per 
acre, a loss of 4 sacks per acre over check. 
Plat V —This seed was exposed to the light 23 days, five months before 
planting. It was then stored in the dugout until May 6th, when it was cut 
and planted. The plants reached the surface of the ground a few days in 
advance of those of the check plat. A number of diseased plans were ob¬ 
served in this plat, but no scab or sclerotia was observed on the tubers at 
harvest time. This seed gave a return of 196 sacks of tubers per acre, a 
gain of 49 sacks per acre. 
Plat VI —This seed was stored in the dugout all winter. On May 5th 
all the stem ends were removed; otherwise the seed was treated like that 
of the check plat. No difference was noticed in the appearance of the plants 
in these two plats. Some of the tubers contained a few sclerotia at harvest 
time. This plat gave a return of 153 sacks of tubers per acre, a gain of 6 
sacks per acre. 
Results. —1. The standard corrosive sublimate treatment gave an in¬ 
creased yield of 45%. The tubers were larger, cleaner and better in every 
way. 
2. Treating seed with corrosive sublimate five months before planting 
gave an increased yield of 9%. The tubers were also larger, cleaner and 
better than those of the check plat. 
3. Treating the seed with a solution of corrosive sublimate, standard 
strength, one hour, five months before planting, and again one hour one day 
before planting, gave a loss of 2%, but the tubers were clean, smooth and 
free from disease. 
4. Exposing the seed to the light 23 days five months before planting 
apparently increased the yield 35%. 
5. Rejecting the stem end piece did not give marked results. 
