38 BOARD OF AGRICULTURE. [Pub. Doc. 



thirty-sixth in the list, — i.e., 21 European varieties proved 

 better than the best American in resistance to rot. 



The above comparison, based only on this one factor, rot 

 resistance of the tubers, does not answer all the practical ques- 

 tions, by any means, but it does serve to emphasize the re- 

 markable differences that exist between varieties . Differences 

 as to resistance in the blighting of the vines showed similar 

 contrasts, though not easy to estimate with like exactness. 

 The same variety did not always show equally good relative 

 resistance in both leaf and tuber. For example, the new 

 Vermont variety, Rust Proof, resists leaf blight to a high 

 degree, but is liable to rot rather badly. There were, how- 

 ever, numerous varieties, especially of the Europeans, where 

 a high degree of resistance occurred against both blight of 

 foliage and rot of tuber. Moreover, differences in resist- 

 ance to scab and to other diseases are being- noted, althouoh 

 Professor Stuart has not as yet published the results of these 

 observations. 



While, as before stated, it is too early to make practical 

 recommendations to growers as to the choice of varieties, 

 certain things are at least evident. The most important 

 are : that wide differences do occur ; that certain varieties 

 are already established, at least in Europe, of high disease- 

 resisting quality. Tliis should at least stinmlate every potato 

 grower and breeder to aim toward improvement in our Ameri- 

 can varieties along these lines. Unfortunately, certain facts 

 stand temporarily and perhaps permanently in the way of 

 our introducing the resistant varieties directly from European 

 to American culture. 



The German varieties are as a class of a coarse quality, 

 used there for factory and stock food, rather than for tal)le. 

 The British varieties, on the other hand, are fine table varie- 

 ties, but are not easily acclimatized here ; they lose then' vigor 

 and productiveness, — at least, for a time. It is possible that 

 with longer culture they may recover it. The outlook at 

 present is, therefore, that American potato breeders must be 

 depended upon — profiting from the experience of the Euro- 

 peans, and using, it may be, these European varieties as 

 parents — to produce similar disease-resisting varieties suited 



