192 The Commercial Apple Industry 



the most influential in improving both annual yield and 

 growth. 



2. In order to dispel any apprehension of great expense 

 involved in applying nitrate of soda, it may be stated that 

 during a ten-year period nitrate of soda was applied at a 

 cost of 9 cents a bushel of fruit produced, or 27 cents a 

 barrel ; and as nitrate was figured at a war time cost of 

 $100 a ton, this shows that even with a very high price the 

 great increase in yield would soon pay for the fertilizer. 

 In these experiments, nitrate of soda was applied at the 

 rate of 4 to 8 pounds to a tree. 



1 3. " It was found that nitrogen from commercial 

 sources or from stable manure proved more effective than 

 that from cover-crop as a rule." Xitrogen from commer- 

 cial fertilizers and from stable manure was particularly 

 effective when accompanied with the proper cultural 

 methods. 



4. " The addition of phosphorus or potash to nitrogen 

 applications has usually given larger returns than nitrogen 

 alone. The nitrogen and phosphorus combination has pro- 

 duced an average increase over the normal yields in two 

 experiments of 265 and 308 bushels per acre annually dur- 

 ing 9- and 10-year periods. This combination is also 

 proving important in one of the experiments in young 

 orchards. In at least three of the other bearing orchards, 

 however, the addition of phosphorus has resulted in no 

 important benefit." 



5. " Neither phosphorus nor lime, when used alone, has 

 shown any important influence on either yield or growth 

 in apples. Lime may often have some indirect value, how- 

 ever, through its favorable influence on leguminous covers 



i Quotations from State Coll. Bull., No. 153. 



