No. 6. 



DEPARTMENT OP AGRICULTURE. 



377 



TABLE II. INFLUGNCE OF FERTILIZERS ON YIELD. (Johnston Or- 

 chard, Experiment 338.) 



(Total yields of fruit on each plot and annual yield per acre.) 



TABLE III. EFFECT OF FERTILIZERS ON YIELD. (Johnston Orchard). 

 (Average returns from certain treatments during past three years.) 



Treatment. 



Totals 3-yr. 

 Ratios, 



Checks. 

 (Av. 1,4, 7, 10) 



4,781 

 lOO 



ft. 



Manure. 

 (Plot 8) 



N- Fertilizer. 

 (Av.2,3,6) 



P.K. -Fertilizer. 

 (Plot 5) 



14,554 

 304.4 

 100 



ft. 



16,226 

 339.4 

 111.5 



ft. 



7,868 ft. 

 164.5 



Average annual yield per acre. 

 Average gain per acre, 



191.2 bu. 



582 bu. 

 390 bu. 



649 bu, 

 457 bu. 



314.7 bu. 

 123 bu. 



These tables are from one of our "combinalion" experiments, in- 

 volving both fertilization and cultural methods,and started in 1908 

 The fertilizers have therefore had a chance to affect the crop only 

 during the past three years, and it is for that period that the totals 

 and annual yields per acre are computed. 



Even a glance at these tables can leave no doubt as to the pos- 

 tive and p>rofound effect of proper fertilization on the yield of apples. 

 It will be noted that the checks run fairly uniform, averaging a 

 little over 190 bushels per acre annually. Lime applications (at the 

 annual rate of 1,000 pounds per acre) have given almost exactly 

 the same returns as the average check. The j)hosphate and potash 

 combination has affected yield in this case rather decidedly, having 

 raised it by 123 bushels per acre. This may be partly due to a 

 slight superiority in location, as indicated by the fact that its ad- 

 jacent check is the highest in yield and is within 8G bushels of the 

 phosphate-potash treatment. While this increase in yield is fairly 

 satisfactory, there is nothing in the growth or appearance of the 

 trees of plot 5 that would lead one to believe that their treatment 

 is appreciably superior to that of the checks. In other words, the 

 trees of plot 5 still look starved and indicate that there is something 

 else lacking, although it will be noted that this is the fertilization 

 ordinarily recommended for orchards. 



