BULLETIN 35, PUERTO RICO EXPERIMENT STATION 
23 
Table 16. — Results of sugarcane variety test* on irrigated, friable, well-drained 
clay at Central Coloso, Irurena farm, Isabela district, 1931-32 — Continued 
Variety, culture, and size of field 
Acre 
yield 
of cane 
Normal juice 
analy^o 
Bogar 
in cane 
Acre 
yield 
Su- 
crose 
Purity 
of 
sugar 
P.O.J. 2714 (11-month ratoons cut in April): 
Field no. 6 (0.75 acre). 
Tons 
29.70 
33.65 
25.59 
26.93 
42.97 
42.10 
11.46 
31.65 
Per- 
cent 
15.47 
15.97 
16.95 
17.07 
13.16 
13.97 
14.33 
15.54 
Per- 
cent 
81.1 
83.2 
86. 6 
85.1 
77.2 
79.7 
80.9 
82.0 
Per- 
cent 
li.c.y 
12.23 
13.18 
13.23 
9.67 
11.18 
10.81 
11,81 
Tons 
3.47 
P.O.J. 2878 (14-month ratoons cut in April): 
Field no. 17 (10.11 acres) 
4. 12 
S.C. 12/4 (14-month ratoons cut in April): 
Field no. 17 (9.06 acres) 
3.37 
P.O.J. 2725 (12-month ratoons cut in February): 
Field no. 17 (2.92 acres).. . 
3.56 
P.O.J. 2878 (13H-month gran cultura cut in January): 
Field no. 11 (13.54 acres) 
P.O.J. 2878 (141.2-month gran cultura cut in February): 
Field no. 12 (24.72 acres) 
4.15 
4.71 
P.O.J. 2878 (20-month gran cultura cut in February): 
Field no. 22 (2.73 acres) 
1 24 
P.O.J. 2878 (21-month gran cultura cut in March to June): 
Field no. 24 (4.87 acres) 
3.74 
On account of differences in harvest dates the juice qualities of the 
different varieties are not always comparable. The most striking 
feature is the generally superior percentage of sugar in cane of P.O.J. 
2878 at Coloso over that of the same variety at Centrals Carmen, 
Constancia, and Plazuela, owing apparently to better drainage, less 
rainfall during the ripening period, and the more suitable soil types. 
A large proportion of the Coloso P.O.J. 2878 cane in 1932 was grown 
on fairly well-drained undulating hillsides of clay soil. Furthermore, 
the lowlands also were largely made up of a fairly stiff soil and were 
not subjected to overflow for protracted periods as were those along 
the north coast. In 1932 at Coloso the sugar in cane of P.O.J. 2878 
fell below 10 percent in only two fields, whereas this value was seldom 
attained along the north coast. 
On the uplands of Central Coloso near Moca the percentage of 
sugar in cane of P.O.J. 2878 was superior to that of P.O.J. 2725. 
In general, however, P.O.J. 2878 was inferior in this respect to both 
S.C. 12/4 and B.H. 10(12). This was due in part to an earlier 
harvest, but P.O.J. 2878 must be harvested early because otherwise 
the next crop makes a stunted growth, due to arrowing. The sugar 
production per month was lower for gran cultura than for primavera 
or first ratoons of P.O.J. 2878. Where irrigation water is available 
and early spring planting can be practiced this is apparently more 
desirable than fall planting, particularly at Isabela where gran-cultura 
canes dry out badly at the top. Fields of P.O.J. 2878 gran cultura 
produced from 0.188 to 0.265 ton of sugar per month at Isabela and 
from 0.211 to 0.359 ton at Moca, Aguadilla, and Aguada. The 
ratoons and primavera produced from 0.195 to 0.36 ton of sugar per 
month at Isabela and 0.307 to 0.48 ton elsewhere. Presumably the 
primavera and first ratoons combined would be more profitable than 
the single gran cultura. The la t ter would occupy the land almost as long 
as the two short-time crops if the resting period between the spring har- 
vest and fall plantingis charged to the gran cultura . Complications that 
arise in trying to adapt such a scheme to the customary harvesting pe- 
riod make it impracticable to discontinue gran-cultura plantings alto- 
gether ; it appears, however, that in the Isabela area there would be some 
advantage in increasing the area devoted to primavera plantings. 
