24 
BULLETIN 31, PORTO RICO EXPERIMENT STATION 
the close of the experiment, 18 months after the first fertilizer 
application had been made, the trees were photographed, those of 
each group being placed in file, thus appearing as a unit (PL 2). 
The leaves were picked November 29, 1915, and weighed. Table 11 
shows the effect of fertilizers on development of the young trees 
as determined by weights at the close of the test. 
Table 11. — Effect of fertilizer on development of young coffee trees in cans as 
shown by weights at close of test 
WEIGHT OF LEAVES 
Fertilizer applied 
N... . 
P.... 
K____ 
NP._ 
NK.. 
PK-. 
NPK 
0___. 
0'____ 
Tree 
No. 1 
Grams 
219 
Tree 
No. 2 
Grams 
219 
92 
100 
96 
79 
228 
203 
105 
215 
89 
84 
222 
256 
117 
90 
62 
87 
Tree 
No. 3 
Grams 
212 
53 
55 
167 
204 
75 
155 
76 
67 
Total 
Gra ms 
650 
245 
230 
598 
524 
248 
633 
283 
216 
Varia- 
tion from 
check 
+367 
-38 
-53 
+315 
+241 
-35 
+350 
0) 
-67 
Weight 
reduced 
to per- 
centage 
of check 
230 
87 
81 
211 
185 
224 
100 
76 
WEIGHT OF TRUNK AND BRANCHES 
N— . 
P.... 
K-.__ 
NP-. 
NK_. 
PK-. 
NPK 
0__._ 
O'.... 
251 
244 
308 
803 
+331 
116 
171 
169 
456 
-16 
149 
141 
141 
431 
-41 
255 
286 
250 
791 
+319 
117 
280 
314 
711 
+239 
165 
157 
150 
472 

257 
308 
237 
802 
+330 
154 
172 
146 
472 
0) 
124 
140 
149 
413 
-59 
170 
97 
91 
168 
151 
100 
170 
100 
WEIGHT OF ROOTS 
N 
P 
K 
NP_. 
NK-. 
PK_. 
NPK. 
O 
O' 
110 
102 
105 
317 
+120 
44 
82 
67 
193 
-4 
62 
57 
69 
188 
-9 
79 
112 
98 
289 
+92 
48 
92 
103 
243 
+46 
64 
74 
74 
212 
+15 
78 
105 
85 
268 
+71 
63 
70 
64 
197 
0) 
53 
i 
59 
69 
181 
-16 . 
161 
98 
95 
147 
123 
108 
136 
100 
92 
TOTAL WEIGHT 
N_ — 
P.... 
K— - 
NP.. 
NK._ 
PK-. 
NPK 
().... 
O'.... 
580 
565 
625 
1,770 
252 
353 
289 
894 
307 
277 
265 
849 
562 
601 
515 
1,678 
270 
587 
621 
1,478 j 
318 
315 
299 
932 
557 
669 
477 
1,703 
334 
332 
286 
952 
239 
286 
285 
810 ! 
+818 
-58 
-103 
+726 
+526 
-20 
+751 
0) 
-142 
186 
94 
89 
176 
155 
98 
179 
100 
85 
i Check. 
The weights stand in a very interesting relation to the fertilizer 
applied. With one exception the weight of leaves from each nitro- 
gen-fertilized tree exceeded that of leaves from each tree receiving 
no nitrogen. The weight of leaves from the nitrogen-treated trees 
