Other Points in Potato Culture. 197 



is. Prof. Bolley, of North Dakota Experiment Station, says: 

 " The first cause of deep potato scab, as studied here, is found to 

 be a plant organism of very minute character, which attacks the 

 surface of young growing tubers, eroding, irritating and blacken- 

 ing the adjacent tissues." It has been found that the disease can 

 be given to a healthy potato by transferring to it some of the scab 

 plant growth from a diseased one. This much having been 

 learned, Prof. Bolley has given much time to experiments in the 

 direction of destroying these scab germs on seed potatoes. I may 

 say briefly that he is satisfied that scabby seed will produce a 

 scabby crop . This has been a much disputed point. Some have 

 claimed that scabby seed was just as good as any other, and no 

 more likely to bring scabby potatoes than was clean seed. In 

 proof, men have declared they planted clean seed and got scabby 

 potatoes, and planted scabby and got smooth. Well, I have been 

 so well satisfied that it was a fungus growth, that I have never 

 planted any scabby potatoes ; but I have now and then had some 

 scabby ones and it was hard to understand where it came from, if 

 it was a fungus or germ disease. Prof. Bolley 's experiments 

 make this more plain. If you have some scabby potatoes in your 

 crop, only a few, say, and pick up and handle them with the rest, 

 the germs may get all over your smooth tubers. Think of how 

 much pains I have taken to get only smooth ones, and picked 

 them up in boxes that had just had scabby ones in and did not 

 know that I was probably spoiling all my care! Again, it is 

 learned that when the scab gets into your land it will stay in the 

 soil from year to year. It is hardly known how long. I know it 

 will stay all right for three years, or while a crop of wheat and one 

 of clover are growing and attack the potatoes the next season. 



What we now want seems to be some way to destroy the 

 germs on the seed first, and then some way to get them out of the 

 soil where they are present. The first we shall undoubtedly soon 

 have ; the second is not so easy. But the treated seed may be put 

 on clean land that has never grown any scabby potatoes and be 

 quite a step gained. If you raised any scabby potatoes, your seed 

 may not be free from it, no matter how smooth, remember, unless 

 you dug it by itself and put in clean packages and kept it away 

 from contamination. If you buy entirely clean seed you do not 

 know whether it is free from scab germs or not. Don't you see, 

 the more we learn, the more trouble there is ahead for us ? Per- 

 haps I realize this more than you, from having tried to plant seed 

 free from scab germs this year. Let me tell you just what we did. 

 Prof. Bolley 's experiments show that soaking the seed in a solu- 

 tion of corrosive sublimate for a time will pretty much destroy the 

 germs. I went to a druggist and got seven papers of corrosive 

 sublimate with two ounces, finely pulverized, in each one. Then 

 I got three good, tight barrels. (I used flour barrels.) Also, three 

 wooden pails. I put two ounces of sublimate in each pail at 



