IL— THE ADAPTABILITY AND USE OF WART-IMMUNE VARIE- 
TIES OF THE POTATO IN THE QUARANTINED AREAS OF 
PENNSYLVANIA. 
By R. E. Haetman. 
The results of experiments to determine the adaptability of the 
common commercial wart-immune varieties of potatoes, Green 
Mountain, Irish Cobbler, Spaulding Rose, and McCormick, have 
shown that these varieties are all well adapted to the present quaran- 
tined areas. ' This is perhaps accounted for by the fact that the quar- 
antined areas of Pennsylvania are all at altitudes ranging from 1,200 
Fig. 2.— Outline map of Pennsylvania, showing the distribution of potato wart as determined bv 
surveys completed in 1921. All infested areas are in coal-mining localities and are generally at high 
altitudes. 
to T 2,000 feet, where the climatic conditions of temperature and rain- 
fall are favorable for potato production. (Fig. 2.) 
The use of wart-immune varieties of potatoes was adopted as a 
quarantine policy in 1920. As a preliminary step in this direction 
all owners of gardens and fields actually infested with potato wart 
were permitted to grow only wart-immune varieties. The particular 
variety selected for this purpose was Spaulding Rose, which is a potato 
of good commercial quality and in addition possesses such outstand- 
ing varietal characteristics that the detection of mixtures is compara- 
tively easy during the whole season of summer inspection. During 
the first season approximately 800 bushels of Spaulding Rose potatoes 
were used with very pronounced success in 300 fields and gardens, and 
in 1921 it was decided to extend the use of this immune variety to 
all the areas under quarantine. 
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