90 



corrosive sublimate solution as described in Bulletin No. 2 H of this 

 Station, page 155, has shown itself to be the most satisfactory of any 

 yet resorted to. In fact the cost of the material required for the treat- 

 ment of several bushels of seed tubers amounts to but a few cents, and 

 the results secured upon most soils have been so excellent that no grower 

 of potatoes who uses lime, wood ashes, or barn-yard manure, or who finds 

 that hissjil is already in such a condition that upon the introduction of the 

 germs, a scabbed crop results, should fail to resort to the treatment at 

 once. The time of treatment which Bolley recommends is one and one- 

 halt hours, and in Brllatin 4 of the North Dakota Station, page 14, he 

 recomuiends the use of 2 ozs. of corrosive sublimate to fifteen gallons of 

 water, which gives a solution of about 1 to 1,000. In i3ulletin 9 of the 

 same Station, he recommends two and one-fourth ounces to the same 

 amount of water or a stronger solution, but nevertheless states on pago 

 30 of the same bulletin that the spore bodies " are destroyed by con- 

 tact with a 1 to 1,000 solution of corrosive sublimate in a comparatively 

 short lifiie." The strength of the solution employed by us was 2 ozs. to 

 fifteen gallons of water, and the treatment was continued one and one- 

 half hours, which, in view of the above mentioned statements and direc- 

 tions, was supposed to be all that was considered necessary for the ac- 

 complishment of the object; and this treatment must ^have m>^t all the 

 requirements of the case, if, as Bolley states, he has never failed to des- 

 tr.^y all scab fungus upon the most deeply fjGabbed seed tubers, for ap- 

 parently the strength of solution was the same as that used by him in a 

 portion of his work. In support of our own results, which indicate that 

 some germs may escape destruction by the treatment, and also that the 

 strength of solution employed by us could not be used as an argument 

 against our results, we cite the following experience of others, viz: L. R. 

 Taft, of the Michigan Station, ^ states that corrosive sublimate, 1 part 

 to 2,000 seems to be as effective as 1 part to 1,000. He also states ^ that 

 soaking the seed longer than one and one-half hours may lessen the 

 scab still more, bat it reduces the yield." C. F. Curtis, of the Iowa 

 Station, ^ found, when using a solution containing two and one-quarter 

 ounces of corrosive sublimate to 15 gallons of water, that a treatment for 

 two hours produced less scab in the product than a treatment for one and 

 one-half hours. J. E. Arthur, of the Indiana Station, * reports results 

 secured in 1893 with corrosive sublimate solution made of a strength 

 of 1 to 1,000 in which a treatment for two hours was more effective 

 than that for one and one-half hours. James Troop, of the Indiana 

 Stati )n, ^ has tabulated the results of three of his experiments in, which 

 by the use of a soltion of 1 to 1,000 the per centage of scab was in 

 every case decreased by ext(3nding the treatment from one and one-half, 

 to three hours. Y. P. Clinton, of the Illinois Station, is also of the 

 opinion that a treatment of three hours is more effective than one of an 

 hour and a half. 



Other experiments as well as that by Troop, above mentioned, 

 point to the conclusion that certain soils, at least, act themselves 



1. Bull. 108. p. 44. 



2. 1. c. 



3. Bull. 27, p, 126. 



4. Bull. 56, pp. 72 and 73 

 6. Bull. 53, p. 122, 

 6. Bull. 40, p. 144, 



