38 
BULLETIN 35, PUERTO RICO EXPERIMENT STATION 
storm risk apparently involved. Data were collected to determine 
the seriousness of this risk and the possibility of reducing it. 
In a l()-aere field at ( 'entral Pagan, An&8CO. P.< ).•!. 2878 was spaced 
90 by 135 centimeters (3 by i : . feet) October 10, 1929, on top of 
hanks in a friable, silty alluvial soil that is subject to overflow. 
(Considerable uprooting was observed in the fall, and the cane lodged 
badly under a moderately strong wind and was therefore cut for 
in January. Counts taken after harvest to determine the percei 
of uprooting showed that of 570 stools along the edges of the ditches 
66, or 11.6 percent, had uprooted, whereas of .~)i)(i -tools in the middle 
rows where they afforded more support for one another only 33, or 6.6 
percent, had uprooted. This indicated that a more closely spaced 
planting would have reduced damages. 
At Central Pagan, in 1930, 20 to 25 percent of the stools in a 10- 
acre field of late-planted gran cultura were blown down. At maturity 
recovery was practically complete and no dead stools were observed. 
The planting of P.O.J. 2878 in September or in October will be helpful 
in overcoming its tendency to uproot; late gran-cultura planting 
results in a young growth of cane in the following late spring and 
summer when wind injury is common; the young stools that are 
blown down do not uproot and thus they occasion very little loss. 
The worst case of uprooting in the San German Valley district of 
Russell & Co. was in a 22-acre field at Hacienda Luisa. Spacing was 
abnormally wide, 90 by 135 centimeters, affording the stools little 
support for one another. Single-bud cuttings were planted on the 
banks. Such plantings are necessarily very shallow, and there is 
much less support against uprooting than where 3-bud cuttings 
with their larger root development and deeper planting are used. 
The percentage of uprooting was determined by examining stools 
in twelve 8-row banks shortly after the harvest, and the clearing of 
the trash. The data were collected in alternate banks so that they 
might be representative of a large area. Of 2,400 stools 381, or 15.9 
percent, had more or less uprooted, but of this number only 2 had 
died and 112 exposed as much as half of their roots. Thus, much 
less than 15.9 percent of the stools were seriously affected by uproot- 
ing. Uprooting was somewhat greater along the edges of the ditches 
than in the middle of the banks. 
The proportion of rotten canes was determined for 200 uprooted 
and 200 normal stools, as shown in table 27. 
Table 27. — Effect of uprooting on percentage of rotten cams 
Locality 
Kind of stools 
Stools 
examined 
Total 
canes 
Rotten canes 
East and north part of field 
Normal. 
Nit mber 
100 
100 
100 
100 
Nu mber 
1.149 
1,126 
1.017 
1.103 
Xu mber 
128 
155 
156 
149 
Percent 
11.2 
Do 
1'prooted. . 
13.7 
West part of field. . 
Normal 
15.3 
Do 
Uprooted 
13.5 
All trash remaining after the field was burned over was removed 
by hand from the stools. The freshly cut cane-stalk stumps were then 
counted. Some cane surfaces of both normal and uprooted stools 
were missed on account of their having been cut below the ground 
