204 The Commercial Apple Industry 



GENERAL SUMMARY AND SPECIFIC RECOMMENDATIONS 



(1). Cost production studies emphasize the importance 

 of high yields. Judicious fertilization is a direct method 

 of increasing yields. 



(2). Nitrogen is the limiting element of plant-food in 

 most orchards. It can be supplied best in one of the 

 following ways : 



(a) Barnyard manure, 8 to 10 tons to the acre an- 

 nually. 



(b) Nitrate of soda, applied two to four weeks be- 

 fore bloom; 3 to 5 pounds to a mature tree 

 under western conditions; 4 to 8 pounds to a 

 tree under eastern and middle western condi- 

 tions. Amount varies with age, size and vigor 

 of tree. 



(c) Growing of such leguminous shade- and cover- 

 crops as alfalfa, clover or vetch. 



(3). Xitrogen tends somewhat to increase the size of 

 the fruit, particularly on weak trees. It increases the 

 number of fruits more noticeably. It may reduce color 

 by checking maturity. 



(4). Phosphorus and potash applied in conjunction 

 with nitrogen have given generally better results than 

 nitrogen alone. This has not been definitely established 

 under western and some eastern conditions. 



(5). Potash may improve color to slight degree. 



(6). The application of about 6 to 8 pounds of nitrate 

 of soda ; 7 to 9 pounds of acid phosphate and from 2 to 3 

 pounds of potash to a mature tree may be considered 

 full treatment for soils generally depleted in fertility. 

 Local tests should be made before extensive application of 



