438 



EXPERIMENT STATION EECOED. 



acre annually for the past 4 or 5 years, depending on the experiment. The 

 fertilizers that have materially increased the yields have also increased wood 

 growth, unless either has increased to an abnormal extent. Phosphates seem to 

 be a partial exception to this rule, and mild injuries also may stimulate yield 

 at the expense of wood growth. 



The following table shows the average benefits over normal results without 

 fertilization for the period 190S to 1912, inclusive : 



Influence of fertiliser elements on apples. 



1 Results for color and size for 1909-1912. 



The value of different elements varies for different orchards, and in one 

 experiment no form of fertilization has yet shown a profitable response. The 

 influence of proper fertilization, however, has thus far been continuous, with 

 a tendency toward maintaining a steady annual yield, except where the yields 

 of the previous year were abnormally high. 



Contrary to the results secured at the Massachusetts Station (E. S. R., 23, 

 p. 342) with low-grade sulphate, high-grade sulphate in the Pennsylvania work 

 has shown no superiority over muriate as a carrier of potash, the reverse being 

 usually true. The author suggests that the low-grade sulphate used in the 

 Massachusetts work may have proved superior on account of its magnesia 

 content. 



Owing to the retarding influence of nitrogenous fertilizers or manure on 

 color, it is advised that they be used less freely on some red sorts, especially 

 those which are tardy in coloring up, such as the York Imperial. This pre- 

 caution is less important on the lighter soils and in localities with long grow- 

 ing seasons. Present evidence indicates that the nitrates, or other specially 

 soluble plant foods, are best applied somewhat after the fruit has set. In 

 addition to greater effectiveness the rate of application may be varied to con- 

 form to a certain degree with the amount of fruit set, thus tending to steady 

 the yield. 



The author concludes that the actual fertilization of a given orchard is still 

 largely a local problem. A local testing plan is here submitted. In lieu of 

 such a test a general fertilizer, based on the experimental results, is recom- 

 mended for bearing trees, as follows: Nitrogen 30 lbs. per acre, carried as 100 

 lbs. nitrate of soda and 150 lbs. dried blood or 150 lbs. ammonium sulphate; 

 phosphoric acid 50 lbs., carried as 350 lbs. acid phosphate, 200 lbs. bone meal, 

 or 300 lbs. basic slag; and from 25 to 50 lbs. potash, carried as 50 to 100 lbs. 

 muriate or 100 to 200 lbs. low-grade sulphate. For young trees these amounts 



