MAINE AGRICULTURAL EXPERIMENT STATION. 1 5 



most striking instances of disease development leading to prac- 

 tical failure of the crop, even under these apparently favorable 

 conditions. The same thing is beginning to show up in certain 

 parts of Utah. 



What is known as the Greeley district, not far from Denver, 

 has been one of the most important potato growing districts 

 of Colorado. This district, which at one time was one of the 

 most noted in the United States, is only about 20 miles long and 

 12 to 15 miles broad at the point of greatest width. Potato 

 growing began here about 1870 and was uniformly successful 

 up to a little less than a dozen years ago when the whole indus- 

 try began to go to pieces. One potato grower told me that in 

 1904 they shipped 14,000 cars within a radius of 15 miles of 

 Greeley. This dropped to 8,000 cars in 1910, and in 191 1 only 

 200 cars were shipped. Others set this last figure at 600 cars. 

 In a few seasons potato growing changed from an important 

 industry to one of little account. Conditions were a little better 

 last year, but were still bad enough then. A recent report from 

 there indicates that the crop of the present season makes them 

 more hopeful. 



The strangest part of this slump in the industry at Greeley is 

 that no two people appear to agree as to the cause of the trou- 

 ble, and they have some very keen, up-to-date men among the 

 potato growers there. There is certainly evidence enough of dis- 

 ease to account for many of the difficulties experienced, for 

 leaf-roll, wilt and Rhizoctonia were almost universally present 

 in a marked degree in the summer ,of 1914. 



Large crops of alfalfa are produced, and potatoes are grown 

 on alfalfa sod. This, of course, tends to increase the nitrogen 

 content of the soil, which latter is claimed by some to be defi- 

 cient in phosphorus. There is a strong probability that some of 

 the trouble may be due to an unbalanced condition of the food 

 materials in the soil, but I could learn of no attempt being made 

 to discover this, or to use any form of commercial fertilizer to 

 correct it if it does exist. Sugar beets are also grown to a con- 

 siderable extent, and some growers maintain that the trouble 

 with potatoes began coincidentally with the introduction of 

 sugar beets. What the connection is between the two, if any, 

 they are unable to state. 



