Jan. 22, 1917 
Effect of Fertilizers on Oranges 
131 
1914 crops. This indicates that nitrogen produced an effect other than 
that of merely delaying the time of maturity. 
The percentage of acid shows the same kind of variation, but in the 
opposite direction. The check, potash, and phosphate plots contained 
0.92 per cent as an average of two crops of each variety, the three being 
in exact agreement, while the plots treated with nitrogen and a complete 
fertilizer show 0.94 and 0.96 per cent, respectively. While this is an 
extremely slight variation, it is interesting to note that it would still 
further tend to accentuate the lower sugar content in its effect on the 
quality of the fruit. The specific gravity of the fruit varied slightly, 
averaging for the four crops as follows: Potash 0.92, phosphate 0.91, 
check 0.91, nitrogen 0.90, and complete fertilizer 0.90. This confirms 
the popular contention that potash fertilizers produce a finer fruit and 
nitrogen a coarser one. The percentage of juice varied with the specific 
gravity, the averages being 49.2 for potash, 49.2 for controls, 48.2 for 
phosphate, 47 for nitrogen, and 47.4 for the complete fertilizer. 
The quantity of nitrogen present in the juice of the fruit is definitely 
correlated with the application of nitrogenous fertilizers. In every case 
the fruit from plots to which nitrogen has been applied shows an increased 
percentage of nitrogen. This would seem to corroborate the figures on 
yields, which show nitrogen to be a limiting factor in crop production in 
this experiment. 
Table) II .—Composition of navel oranges fertilized differently 
Fertilizer and plot. 
Crop of 1914. 
Crop of 1915* 
Spe¬ 
cific 
grav¬ 
ity. 
Juice. 
Sugar. 
Add. 
Nitro* 
gen. 
Specific 
gravity. 
Juice. 
Sugar. 
Add. 
Nitro¬ 
gen. 
Per 
Per 
Per 
Per 
Per 
Per 
Per 
Per 
cent. 
cent. 
cent. 
cent. 
cent. 
cent. 
cent. 
cent. 
Dried blood, plot C. 
0.91 
47.1 
9. 28 
1.09 
0.088 
0.89 
40.4 
to. II 
0.98 
0.130 
Nitrate of soda, plot H. 
.90 
45*5 
9.11 
1.09 
• 095 
.87 
38* 2 
9.26 
*94 
•137 
Dried blood, plot S. 
.88 
44*5 
8.86 
i* 13 
. 102 
.88 
40. 7 
10.05 
•99 
.117 
Average. 
.90 
45*7 
9.08 ■ 
1.10 
■095 
.88 
39*8 
9.81 
•97 
.128 
Sulphate of potash, plot D. 
.92 
45*5 
9 * 65 
1.08 
.076 
.91 
44*4 
10.92 
•97 
.086 
Muriate of potash, plot I.. 
.91 
46.9 
9*44 
1.11 
•075 
.92 
45 *o 
10.46 
.96 
•093 
Sulphate of potash, plot R. 
.89 
45*9 
9.04 
1.12 
.081 
.90 
43-9 
9.92 
•97 
.081 
Average. 
.91 
46.1 
9*34 1 
| 1.10 
.077 
.91 
44.4 
10.43 
•97 
.087 
Steamed bone, plot E. 
.90 
46.9 
9.69 
1.01 
.082 
.90 
42*9 
10.82 
.90 
•093 
Superphosphate, plot J. 
.90 
47*5 
8. 79 
1.08 
.081 
.90 
40.1 
10.41 
■97 
.098 
Superphosphate, plot N. 
.89 
47 *o 
9. 00 
1.10 
.070 
.89 
41.7 
io* 12 
1. 02 
.097 
Steamed bone, plot P. 
.90 
47*8 
9 * 14 
1*13 
.082 
.89 
41*4 
10.47 
.98 
.097 
Average. 
.90 
47*3 
9*15 
1.08 
.079 
.90 
4 i *5 
10.46 
•97 
.096 
Complete fertilizer, plot A... 
.90 
47*3 
9. 06 
1.11 
. 087 
.88 
41* 7 
9.46 
.98 
. 126 
Complete fertilizer, plot Q. 
.89 
44*8 
9*05 
1*13 
. 1,02 
.88 
41*1 
9.99 
1.00 
.124 
Average. 
.90 
46.1 
9.06 
1.12 
.095 
.88 j 
41*4 
.. 9*73 
•99 
• 125 
f'|npr | 1? pint P 
• Ql 
a* 7, K 
9,39 
I. 06 
. 072 
Missing. | 
Check, plot M. 
.89 
46.9 
9.04 
I.07 
.084 
• 90 
43 *i 
io. 23 
.98 I 
.096 
Check, plot T. 
.88 
45*8 
9*47 
1.12 
.082 
.90 j 
43*6 
10. 80 
.92 j 
.087 
Average... 
.89 
46. 7 
9*30 
1. 08 
.079 
.90 
43*4 
10. 51 
.95 j 
.092 
