10 



the difference in yield between the sprayed and unsprayed pota- 

 toes was not as great as it would be ordinarily. Again, it is 

 possible that with the desire to make the treatment thorough, 

 more materials were used and more time taken than was actually 

 uecessar}'. At each spraying 150 gallons of Bordeaux mixture 

 per acre were used. The mixture was made according to the 

 following formula : 



Blue Vitriol 5 lbs. 



Lime (Fresh)... 5 lbs. 

 Water .^0 gallons. 



The blue vitriol cost, in 25 pound lots in Boston, G cents per 

 pound, and about 6.^^ cents laid down. The lime was purchased 

 in small quantities, and cost 1 cent per pound. 



At these prices 150 gallons of Bordeaux mixture cost $1.12|^, 

 or about | of a cent per gallon. In spraying an acre, two men 

 were employed eight hours at 15 cents per hour; the time 

 expense was S2.40. The actual time of spraying was six hours ; 

 two hours were occupied in obtaining water, making the mix- 

 ture, etc. 



It is probable that the expense for labor can be considerably 

 reduced. The total expense will vary with the luxuriance of 

 the vines, the number of applications required, the local cost 

 of materials, the form of apparatus used, and the convenience 

 of water. It is our belief, however, that spraying against the 

 early blight will be found to be a profitable operation. 



Late Blight of the Potato. — The late blight, or the rust or 

 rot, as it is often called, makes its appearance usually about 

 the first of August. It is characterized by the rapid withering 

 and dying of the leaves, and by the appearance on the under 

 side of the affected leaves of a fine white mold-like growth, 

 which consists of the spores and spore stalks of the fungus 

 producing the disease. The tubers are usually more or less 

 affected. If the weather is warm and wet, the course of the 

 disease is very rapid. 



The early and the late blight are often present together. 



I'OTATO SCAI'.. 



Within a few years it has been found that this serious disease 



