




Experiments in Treatment of Potato Scab. 

Experiments were conducted during 1892 both at the Station 
and in co-operation with Mr. C. E. Chapman, of Peruville, N. Y., 
for the purpose of investigating the following questions: 
1. To what extent can potato scab be prevented by treating 
the seed with fungicides? 
2. Is spraying the seed and the surrounding soil as effective 
in preventing scab as soaking the seed before planting? 
3. What are the comparative merits of different fungicides for 
the prevention of potato scab? 
General observation will confirm the statement that under 
favorable conditions the scab fungus will live from year to year 
in the soil. Such places are known to produce a scabby crop 
whenever they are planted to potatoes. Sometimes they become 
so badly infested with the scab that they are no longer planted 
with potatoes on that account, thus showing that the soil has 
become permanently infected with the scab fungus. In the fol- 
lowing pages such soil will be referred to as “infected” soil, 
meaning that it is infected with the potato scab fungus. So far 
- as our observation goes badly infected soils are usually found on 
the former site of a cattle yard, door yard or kitchen garden or 
perhaps where a portion of a straw stack has rotted or in some 
such location where the soil has been abundantly enriched and 
successive crops of potatoes grown. 
In planning the work with potato scab for the past season it 
was decided to secure if possible some thoroughly infected land 
for a portion of the experiments in order to give the proposed 
remedies the severest possible test. Through the courtesy of Mr. 
©. E. Chapman, of Peruville, Tompkins county, N. Y., a piece of 
such ground was offered free of charge for this work and Mr. 
: ~ Chapman, who is an experienced potato grower, and who also 
_ appreciates the necessity of very careful work in conducting such 
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