6o 



yields of the first year are excluded because they can never be 

 materially affected by the applications of the first season. The yields 

 are given in pounds, and also in bushels per acre annually for the 

 last four years. 



Table II. — Influence of Fertilization on Yield. 



(Johnston Orchard.) 

 {Yields in pounds and bushels per acre; 1908-1912.) 



Plot 123456789 10 



Check Nit. & Nit. & Check Phos. & Comp. Check Manure Lime Check 

 Phos. Potash Potash Ftlzr. 



Lb. Lb. Lb. Lb. Lb. Lb. Lb. Lb. Lb. Lb. 



1908 90 528 237 446 57^2 759 211 278 558 106 



1909 675 6,018 5,257 1,932 3,089 6,621 2,008 3,531 1,216 1,266 



1910. 2,575 3,265 1,822 3,168 3,552 2,108 1,629 6,149 3,185 3,505 



1911 283 7,563 7,816 617 1,227 8,209 1,362 4,874 388 106 



1912. 1,024 1,225 696 1,382 1,385 189 1,226 6,698 741 474 



Total 4 yrs., . 4,557 18,071 15,591 7,099 9,253 17,127 6,225 21,252 5,530 5,351 



Bu. per A. An- 

 nually, 136.7 542.1 467.7 213. 277.6 B13.8 186.7 637.5 165.9 160.5 



An. Gain over 

 Chk * Bu. per 



Acre, 377.9 293.5 103.4 339.6 463.3 8.3 



♦The average check or unfertilized plot produced 174.2 bushels per acre annually 

 during 1909-12. 



In the first place, it will be noted that the checks, or unfer- 

 tilized plots, have run fairly uniform, producing an average annual 

 yield of 174.2 bushels per acre during the last four years. Lime 

 alone (at the rate of 1,000 pounds per acre annually) has shown no 

 improvement over the average check, and as a matter of fact it has 

 averaged 8.3 bushels per acre less, a deficit that is doubtless largely 

 or wholly due to incidental and natural fluctuations. The phosphate 

 and potash combination has afiPected the yield here rather distinctly. 

 This may be at least partly due to a possible advantage in location, 

 as indicated by the fact that its adjacent check is the highest pro- 

 ducer among them and is averaging within 64 bushels of the phos- 

 phate-potash treatment. The growth on the latter plot, however, is 

 nearly 3 per cent, less than the normal unfertilized plot, and its 

 general appearance is not appreciably superior to that of the checks. 

 It is evident, however, that these trees are still vitally in need of 

 something, although it should be noted that they are receiving the 

 fertilization commonly advised for orchards, — largely on the basis 

 of chemical analysis 



This need is being quite thoroughly met on the adjacent plot 6, 

 which differs from number 5 only in the addition of nitrogen. The 

 mere addition of nitrogen in this case has more than tripled the gain. 

 Wherever nitrogen appears in the treatments very large yields are 

 observed, and the foliage and growth of the trees are very satis- 

 factory, — the average gains in trunk-girth ranging from 25 to 90 

 per cent. 



