' FERTILIZERS FOR COFFEE IN PORTO RICO 5 
Table 2. — Average weight of cherries per coffee tree for the 8-year period 
1917-1924, from differently fertilized plats ranked in sequence of production 
Plat 
No.i 
Fertilizer 
Relative 
quantity 
of ferti- 
lizer ap- 
plied 2 
Weight of 
cherries 
Plat 
No.i 
Fertilizer 
Relative 
quantity 
of ferti- 
lizer ap- 
plied 2 
Weight of 
cherries 
58 
NK - 
16 
8 
8 
2 
4 
8 

16 
16 
4 
1 
2 
8 
16 
4 
4 
2 

4 
1 
Grams 
32, 556 
27, 239 
27,211 
26, 808 
25, 194 
24, 782 
24,028 
22, 529 
21, 692 
21, 075 
20, 687 
19, 880 
19, 874 
17, 190 
16, 085 
16, 009 
14, 335 
12, 943 
12, 540 
12, 524 
27 
15 
26 
35 
25 
51 
22 
45 
54 
11 
23 
16 
41 
18 
13 
38 
12 
42 
57 
52 
P 
2 
1 
2 
4 

16 
2 
8 

1 
2 
] 
8 

1 
4 
1 
8 
16 
16 
Grams 
12,294 
12, 102 
43 
NK 
PK... 
46 
NPK.. 
K 
12,064 
12,032 
11,845 
28 
N 
N 
36 
NK.... 
None 
48 
PK 
PK 
11,830 
47 
None 
PK 
11,447 
11,014 
53 
NPK 
NP 
55 
K 
None.. 
10,990 
10,804 
33 
K 
K 
14 
NK 
NP 
10, 774 
24 
44 
56 
37 
NPK 
NP 
10, 663 
10, 333 
9,447 
K 
P 
P... 
None__ 
PK 
N 
NP.. 
7, 121 
31 
NPK.. 
5,696 
21 
NK 
P 
5, 145 
32 
None 
N 
N____ 
NP 
3, 880 
2,708 
34 
P 
17 i 
NPK... 
1,454 
1 Seventeen trees either died or were so badly injured as to necessitate excluding from crop records. These 
included one tree each for the following listed plats: Division 1, NK, 1918-1924; PK, 1924; O, 1919-1924; 
division 2, NP, 1919-1923; N, 1918-1924; N, 1919-1924; division 3, P, 1918-1923; N, 1923; PK, 1918-1923; 
division 4, P, 1919-1923; P, 1921-1924; K, 1923-1924; PK, 1924; division 5, PK, 1919-1923; NPK, 1918-1923; 
P, 1919-1923; N, 1919-1923. 
2 Quantity applied in comparison with lowest quantity expressed as 1. 
The general trend of future performance was indicated in the 
plats receiving the heavier applications as early as the first impor- 
tant crop, which was produced four years after seeding and three 
years after setting. Here, it appears that potash, especially when 
used in addition to nitrogen, was effective in increasing crop yield. 
This is shown much more clearly in the curves for the 1924 crop. 
In this crop 11 plats yielded better than the best check. These agree 
is one particular only. All received potash, 4 received nitrogen only 
in addition to potash, 1 received phosphoric acid only in addition 
to potash, and 3 received both nitrogen and phosphoric acid in ad- 
dition to potash. Table 3 shows the 12 plats of highest yield, ranked 
in sequence of average production per tree. 
Table 3. — Showing 12 plats of highest yield, 192^, ranked in sequence of average 
production per tree and their fertilizer treatment 
Plat 
No. 
Fertilizer 
Relative 
quantity 
of fer- 
tilizer 
applied • 
48 PK.. 
58 I NK.. 
55 K_... 
43 NK.. 
33 K._._ 
24 NPK 
8 
16 
16 
8 
4 
2 
Yield of 
cherries 
per tree 
Grams 
9,935 
8,524 
7,713 
7,415 
6,623 
6,424 
Plat 
No. 
46 
53 
36 
14 
44 
47 
Fertilizer 
NPK 
NPK 
NK.. 
NK.. 
K___. 
None 
Relative 
quantity 
of fer- 
tilizer 
applied ' 
8 
16 
4 
1 
8 

Yield of 
cherries 
per tree 
Grams 
6,421 
6,302 
6,271 
6,038 
5,874 
5,811 
i Quantity applied in comparison with lowest quantity expressed as 1. 
