No. 



(. 



DEPARTMENT OF AGRICULTURE. 



233 



The first three experiments, 215, 216 and 220, comprise what we 

 call our straight fertilizer experiments; the next four are experi- 

 ments on cultural methods, with and without manures; and the 

 last four are a combination of fertilizer and cultural methods ex- 

 periments. 



Each of the fertilizer experiments contains sixteen plots of ten 

 trees each. The treatments are shown in Table 11. The symbols 

 N, P and K refer to nitrogen, phosphates and potash; and they 

 are applied at the rates of fifty pounds N., 100 pounds P2O5 and 

 150 pounds KoO per acre in all cases. Plots 5 and 6 compare the 

 muriate and sulphate as a carrier of j^otash. Plots 11 and 12 com- 

 pare acid phosphate and "floats" as a carrier of phosphoric acid 

 (phosphorus pentoxid, more correctly). The manure was applied 

 at the rate of twelve tons per acre and the lime at 1,000 pounds per 

 acre. All applications are made annually. 



The combined results to date of the first three experiments are 

 shown in Table II: 



TABLE II 



Influence of Fertilizers on Yield, Color and Growth 



Expts. 215, 216. 220 



1 



2 



3 



4 



{) 



ti 



7 



8 



9 



10 



11 



12 



13 



14 



15 



16 



Cheek, .. 

 N. P., .. 

 N. K., .. 

 Check, .. 

 P. K., -. 

 PK2SO4, . 

 Check, ... 

 N. P. K., 



N., 



Check, .. 

 Acid P., . 

 Raw P., . 

 Check, ... 

 Manure, . 



Lime 



Check, ... 



4,643 

 6,887 

 5,653 

 2,313 

 3,577 

 2,773 

 1,998 

 3,847 

 4,709 

 2,898 

 2,833 

 1,548 

 2,209 

 4,793 

 1,538 

 1,843 



78.1 

 82.8 



62.5 

 32. 



67.4 

 81.2 



"h'.'^h' 



-36.6 



nh'.z 



-21-7 



1,306 

 1,770 

 1,409 



897 

 1.441 

 1,664 

 1,067 

 1,561 

 2,675 

 1,431 

 2,126 

 1.073 

 1,327 

 3,423 



895 

 1,034 



51.2 

 36.4 



56.5 

 76.3 



31.3 

 104.2 



52.2 

 -21.3 



178.5 

 -21. 



69.2 



47.9 



57. 



72.7 



69.8 



67.2 



59. 



41.6 



43.8 



67.8 



69.3 



75.3 



62.5 



56.0 



68.7 



70.2 



-22.5 

 -14.5 



1.7 

 3.6 



-20.3 

 -21.1 



3.3 

 11. 



-9.1 

 -.9 



•The per cent, of benefit is obtained in all cases by comparing the "normal performance" of 

 each plot with the results actually secured, the normal being obtained by comparison with the 

 two nearest checke. 



tin all these tables the effects on color and size of the fruit were obtained from random 

 samples, taken from the fruit of eacli tree as it was weighed, the aggregate sample from each 

 plot amounting uiually to one or two bushels. The data on yield and growth were obtained 

 by weighing all the fruit and measuring all trees twice. 



Striking things shown here are the strong beneficial effects of 

 manure and of nitrogen on yield and growth, with an accompanying 

 harmful influence on color. Plots 6 and 11 show surprising gains 



