CONCLUSION. 
The corticium or fruiting stage of this fungus develops freely on the 
green stems of the infected plants. However, it is evident that the sclerotia 
which are so common on the stems and tubers are also prominent factors 
in disseminating this disease. 
Experiments indicate that treating infected seed with the standard 
formalin solution usually improves the appearance of the crop, but appar¬ 
ently weakens the plants and is apt to be the means of cutting down the 
total yield of tubers per acre. 
The corrosive sublimate solution improved the appearance of the crop 
and gave marked gains when the treated seed w T as planted on new land. A 
weak solution, one ounce to ten gallons of water, gave better results than 
the standard when the seed was dipped in sacks and planted on old potato 
land. 
Liming the soil at the rate of 3,000 pounds to an acre apparently did 
not check the disease. 
Thoroughly covering the seed with sulphur also gave negative results. 
The burning of all vines and weed stems as soon as the crop is har¬ 
vested is an excellent practice. 
Carefully selecting clean, smooth, round seed from a lot of tubers com¬ 
paratively free from disease gave excellent results. 
The shape and appearance of tubers give a hint as to their seed value, 
but their crop record and care of tubers after they are harvested are also 
important factors to be considered in selecting seed. Cull seed is a poor 
investment for a commercial grower at any price. 
Spreading the seed tubers on a root house floor, where they were dry 
and more or less exposed to the air and light for five or six weeks before 
planting gave good results. 
Seed tubers keep best when stored in small lots in comparatively dry, 
well aerated cellars which are kept at a temperature of about 40° F. 
Good seed is one of the essential factors in successful potato culture; 
still various soil conditions seem to be fully as important. This is especially 
true where the soil is infected with this fungus. Observations indicate that 
diseased plants growing in soils well supplied with plant food are usually 
more successful in resisting the attacks of the fungus than those growing in 
soils more or less deficient in their chemical composition. 
Poorly aerated soils are also more favorable for the development of 
this fungus. Soils which have a tendency to bake or form crusts need fre¬ 
quent cultivation. This is especially true while the plants are young. Plants 
which are thoroughly cultivated and carefully irrigated are apparently 
better able to overcome the attacks of this fungus and the tubers are usually 
free from scab. 
Too much attention cannot be given to watering. If the rows are too 
long the field ought to be divided into sections, so as to be able to apply 
the water more evenly, and thus prevent part of the field from becoming 
too wet and soggy. Apply less water and irrigate more frequently. If the 
ground bakes or forms a crust, cultivate the field as soon as it becomes suf¬ 
ficiently dry. Keep the soil well aerated if possible. 
Deep runs are also usually more desirable than shallow ones, since 
by this means the roots can be supplied with plenty of moisture and at the 
same time prevent the soil where the tubers are forming from becoming 
too wet, and they also furnish a better circulation of air at the base of the 
plants, thus making the conditions less favorable for the development of 
this fungus. 
