No. 4.] 



PLANT DISEASES. 



37 



be considered as justifying final conclusions, and he has no 

 practical recommendations to make to potato growers as yet 

 relative to varieties for culture. Certainfy none of the 

 European varieties are as yet sufficiently tested to justify 

 recommending them for other than trial plantings. 



It is most encouraging and significant, however, to find 

 that not only do the European varieties in general retain 

 much of their disease-resisting qualities when grown in this 

 country, but that they are strikingly superior to even the 

 better of the American varieties in this respect. This will 

 appear from the following tabular summary of the first year's 

 results : — 



Relative Disease Resistance of European and American Potatoes. 



These figures show only the averages. Professor Stuart's 

 figures show many interesting details, which emphasize even 

 more strongly these differences in disease liability. Thus, 

 two varieties, one German (Irene) and one English (Eldo- 

 rado), showed no rot whatever ; whereas in the same field the 

 French variety Chave showed 96 per cent rotten, and the 

 Americans Early Rose showed 89 per cent and Ionia Seedling 

 showed 85 per cent rotten. Two American varieties have a 

 pretty well-established reputation among potato growlers for 

 resisting the rot, — these are the Dakota Red and Keeper. 

 These two proved that their reputation is deserved, for in 

 these trials they led all American varieties in this respect ; 

 but in comparison with the Europeans the}^ were decidedly 

 inferior, Keeper standing twenty-second and Dakota Red 



