1907.] DISEASES OF THE POTAtO. 221 



blight has infected a field seriously I have never seen an indi- 

 vidual plant that would stand up against it. We have thought 

 that there might be certain varieties which were resistant to the 

 blight. Part of these observations are based upon these conclu- 

 sions, but in order to judge one variety as compared with 

 another we should have it in the same field side by side and 

 subject to the same conditions. They must be compared on 

 practically the same conditions. You cannot have a good 

 season for blight and compare a plant with another variety 

 another season when the conditions are different. You cannot 

 compare them with another variety and another season, but 

 a man may have one set one time and another another. Mr. 

 East is interested at the Experiment Station in potato culture, 

 and I am interested in diseases. He has planned some experi- 

 ments which will aid me. On a large field he has secured 

 quite a number of varieties, about eighty, which we intend to 

 grow on a small scale. My part of the work will be to watch 

 these, and see if there is any difference in the varieties, so far as 

 the resistant powers to disease are concerned. With that idea 

 I imported the Scotch potatoes, w^hich were said to be especially 

 resistant to blight. They being imported and not acclimated, 

 they did very poorly the first year, as all potatoes do, and 

 the year was not a favorable year to test them for the blight, 

 because there was no blight. There was quite a difference 

 in the varieties, however. There were three varieties that 

 remained green and stood up well until they were killed by 

 the frost. Most of the others died early. This is the second 

 point of my study. 



The third point is on this matter of rotting of the tubers, 

 I sent out a circular last spring, asking certain farmers to test 

 ridging up of potatoes as a means of preventing tuber rot. 

 I recommended that that method of culture be tried to see if 

 it made any difference. I am not advocating ridge culture 

 here or claiming at present that it has any advantage over the 

 other. That is not the point that I am trying to bring out. 

 What I wanted to do was to test my idea with reference to 

 the falling of these spores. If the potatoes were buried to a 

 greater depth, and therefore more safely hidden or kept from 

 the spores they would be less subject to the rot, and have a 



