EXPERIMENTS IX POTATO CULTURE. 125 



bushels. As this is but a single trial, I do not attach much impor- 

 tance to it. The trial will be continued and conclusions will not be 

 drawn until after five years. We often make great mistakes b\' 

 drawing conclusions from one or two years' trial. It is only by 

 years of careful trials, not of whole fields treated alike, but of dif- 

 ferent methods arranged side by side, so there shall be the least 

 possible difference between the soil and treatment in the different 

 methods, that we can ever expect to make progress and settle dis- 

 puted points. While I am satisfied that in all my trials with the 

 potato scab I have made but little progress in gathering information 

 as to its character or its cause, I cannot help thinking that, for rea- 

 sons I do not understand, fresh barn manure is more likely to cause 

 it than well decomposed manure, and also that commercial fertilizers 

 produce better potatoes than barn manure when put in the hill, what- 

 ever may be its condition. In my practice I have thus far secired 

 potatoes free from scab by harrowing in the barn manure and put- 

 ting a small quantity of commercial fertilizer in the hill, except when 

 I have planted on low, wet land. Fresh manure placed in the hills, 

 if it does not produce the scab, will on m}^ land often draw the gray 

 wire worm in such quantities as to ver}' much injure the potatoes. 

 My impression is that commercial fertilizers have a tendency to drive 

 the worms away from the potato hills. 



From the numerous experiments I have tried I am convinced that 

 in ordinar}- soil a large piece of a potato is better to plant than a 

 small piece, and that it is better because the young plant draws 

 nourishment from the potato more readily than from the common 

 soil. I am also convinced that a small whole potato is better than 

 a piece of the same size cut from a large potato, not because the 

 potatoes are small, but because, the skin being unbroken, the life of 

 the potato is not weakened as it is when the potato is cut open and 

 the interior is exposed to the air and the action of the soil. 



The condition which a potato is in has much to do with the amount 

 of product at harvest time. If the potato be healthy, with strong 

 eyes, the young plant starts off with great vigor ; but if it be dis- 

 eased, with small, weak e3'es, the plant starts feebly and never re- 

 covers sufficiently to produce a large crop unless the land is in the 

 best possible condition. A very rich and well- prepared soil will do 

 much to overcome a weakness in the seed or tuber. A single eye 

 in a soil as rich in plant food as the potato itself will produce a good 

 crop. It is this fact that has led many to believe *that single eyes 



