Second Report on Potato Culture. 6 







from attack, but the later ones are especially subject to the disease. 

 This, however, is not necessarily due to the foliage of such varieties 

 being more susceptible, but rather to the habits of the fungus. I have 

 not observed that the age of the potato plants has a marked influence 

 upon the spread of the disease ; nor that the young foliage of the 

 plants is less subject to the disease. It appears as if the parasite is 

 able to thrive upon all potato foliage which is in a healthy condition at 

 the time of the germination of the spores, and that old and young 

 foliage or plants suffer practically to an equal extent."* 



" Acceptable evidence of a resting stage or oosporic form of this 

 fungus is lacking, and many beheve that the fungus threads survive the 

 winter in the partially diseased tubers."! 



The important question and the question which concerns every 

 potato raiser is, *' Is there any practical remedy or preventive for the 

 potato blight ? " Fortunately there is, and there is no more reason 

 now for a farmer to permit his potatoes to be destroyed by the blight 

 than to permit them to be destroyed by the potato-beetle. The stand- 

 ard preventive is the Bordeaux mixture. This, if properly made (see 

 page 69) and properly applied, will protect potatoes from the late 

 blight and the consequent potato rot. Had this treatment been gen- 

 erally practiced in New York state this year it would have meant the 

 saving of thousands of dollars to the farmers. Had the Irish peasants 

 been properly instructed upon the use of Bordeaux mixture, and had 

 they followed faithfully the instructions given, the threatening famine 

 in Ireland might have been averted. 



As has been stated, the treatment for blight consists in preventive 

 measures, and this is, without doubt, the reason why potatoes are often 

 neglected, as the necessity for treatment may not be apparent until too 

 late. 



The record of spraying on the experimental plats this year is as 

 follows : 



June 18, sprayed with Bordeaux mixture and Paris green. 



July 6, " " '' " " " " 



July 21, '' " " " " " " 



August 12, *' 



a i< 



* E. G. Lodeman, Cornell Bulletin 113. 

 f B. M. Duggar. 



