Z BULLETIN 3 4, PORTO RICO EXPERIMENT STATION 
the tree. At San Jose fertilizer treatment was begun less than two 
years after the date of planting the nuts, and production of the 
palms was recorded during the first 15 years. At Corsica the palms 
were about 16 years old at the time they received the first fertilizer 
application, and production was recorded for approximately seven 
years. At Boquillas the palms were decidedly older than those at 
Corsica, and production was recorded for more than 11 years. Indi- 
vidual production records of nearly 500 palms over a period of years 
have yielded data which are important not alone as showing produc- 
tion following the application of certain fertilizers, but for what is 
of broader value, information as to the bearing habits of the coconut 
palm. This bulletin gives the results of the observations and con- 
tains information that should be of value wherever the coconut is 
grown. 
SAN JOSE PLANTATION 
The San Jose plantation of the Harvey brothers is located near the 
coast and a few miles east of San Juan. The soil is a sandy loam 
and apparently of uniform texture in the area selected for the fer- 
tilizer tests. Late in the fall of 1913 unsprouted nuts were set in this 
plantation in carefully alined rows 33 feet apart each way. For 
treatment the trees were grouped in 1915 in nine plats of parallel 
rows of 10 palms each. No guard rows were left between the plats, 
as it was originally intended to continue the experiment for only a 
limited time after the palms should come into bearing. 
TREATMENT 
Table 1 shows the treatment given the different plats. 
Table 1. — Fertilizer treatments, yield of coconuts, and distribution among the 
plats of the 25 least and the 25 most productive palms, at San Jos^ 1 
Plat 
No. 
1-9 
Fertilizer applied semiannually 
from July, 1915, to January, 1926 
Salt (NaCl) 
Nitrogen and phosphoric acid 
Nitrogen and potash 
Phosphoric acid and potash 
No fertilizer 
Nitrogen; phosphoric acid; and 
potash 
Nitrogen; phosphoric acid; and 
potash (in double quantity) ... 
Cow manure supplemented with 
phosphoric acid and potash 
Tobacco stems supplemented 
with nitrogen and phosphoric 
acid ._ 
Average or total 
Average production of nuts per palm in — 
1920 
No. 
13 
5 
7 
3 
1 
4 
1 
3 
1921 
No. 
45 
41 
36 
19 
11 
31 
32 
20 
38 
30 
1922 
No. 
69 
64 
64 
44 
36 
67 
66 
42 
51 
56 
1923 
No. 
74 
84 
78 
73 
60 
73 
68 
59 
67 
70 
1924 
No. 
90 
95 
76 
70 
56 
75 
80 
66 
76 
76 
1925 
No. 
70 
72 
53 
47 
45 
56 
59 
51 
55 
56 
1926 
No. 
68 
82 
67 
64 
57 
71 
76 
68 
74 
69 
1927 
No. 
75 
72 
54 
57 
52 
65 
59 
59 
66 
62 
1928 
(half 
year) 
No. 
39 
43 
29 
27 
35 
30 
34 
41 
42 
35 
1920- 
1928 
No. 
544 
558 
465 
403 
352 
472 
474 
407 
477 
460 
Distribution 
among the plats 
of the — 
25 least 
pro- 
ductive 
palms 
No. 
25 
25 most 
pro- 
ductive 
palms 
No. 
25 
1 A single palm was lost during the course of the experiments (palm No. 28 from plat No. 2). As this 
loss occurred after less than two years of production, the palm has not been included in the totals and the 
averages. The full-time averages are not identical with the sums of annual averages on account of the 
fractions added to or deducted from the latter . 
