like it, consists of mycelial threads which grow in the 

 tissues of the leaf and send out spore-bearing stalks on 

 the surface. The early blight may be distinguished from the 

 late blight by its characteristic spots, by the absence of the 

 mould-like fuzz of the latter, by its earlier appearance and 

 slower growth, and from the fact that it does not affect the 

 tubers. Both diseases may be present in a field at the same 

 time. 



Our experiments have not yet definitely decided the question 

 whether the Bordeaux mixture is as effective a remedy for the 

 early blight as for the late, but the indications are favorable. 

 Our experiments last summer were planned for the ordinary 

 blight, but that did not make its appearance in this vicinity and 

 it was rather late when our attention was directed to the new 

 disease. Several plots were sprayed about the middle of 

 August, and while the vines were finally killed, those which 

 were sprayed resisted the disease about two weeks longer than 

 the unsprayed. 



One of the sprayed plots yielded twenty bushels per acre 

 more than a similar unsprayed plot, while in another field a 

 small sprayed plot yielded nearly double the weight of merchant- 

 able potatoes that the unsprayed plot beside it did. In treating 

 the early blight the spraying should be commenced by the mid- 

 dle of July, or earlier, if signs of the disease make their appear- 

 ance. 



BORDEAUX MIXTURE. 



Blue vitriol (copper sulphate) i lb. 



Fresh lime . . . . . . . . . i lb. 



Water logals. 



or 



Blue vitriol • • 5 lbs. 



P"resh lime . . . 5 lbs. 



Water 50 gals, or i barrel. 



Dissolve the blue vitriol in several gallons of water, say one 

 fourth the quantity to be used, or it may first be dissolved in a 

 smaller quantity of hot water and then several gallons of cold 

 water added. Slake the lime and make a thin whitewash, then 

 pour this slowly into the solution of blue vitriol, stirring 



