16 BULLETIN 54, HAWAII EXPERIMENT STATION 
it from impurities. The starch has a glossy appearance, with a 
decided glisten in certain lights, in marked contrast with the smaller- 
grained starches which are of dull and amorphous appearance. 
When cooked it forms a semi translucent, rather sticky mass, such 
as is characteristic of potato or arrowroot starch but different from 
the opaque gel obtained from corn starch. Since pure starches are 
tasteless, the flavor of the resultant product is, of course, the same 
regardless of the kind of starch used. The starch is often recom- 
mended for use for invalids and for infants, due to its large granules. 
SUMMARY 
Under Hawaiian conditions edible canna can be grown during any 
season of the year. It produces its maximum yield, however, when 
grown for a definite period at an altitude of less than 1,500 feet. 
The crop is adapted to either long or short-rotation periods, and 
requires a loose, loamy, and well-drained soil for best development. 
Cultivation is essential when the crop is grown in a hard, compact 
soil. 
Edible canna is free from attacks of injurious insects and plant 
diseases, and produces an average of 18 to 20 tons of tubers per 
acre. The tubers have excellent keeping qualities. Only vigor- 
ous tubers which bear unbruised buds should be selected for propa- 
gation. 
The average composition of a hill of edible canna tubers varies 
little regardless of the period of growth. Weather changes stimulat- 
ing new growth may cause temporary variation, however. 
In an examination of immature, mature, and old tubers from a 
single hill, the immature tubers were found to differ considerably 
from the mature and old tubers, which were similar in composition. 
Decided changes in the composition of the tops were observed to 
occur in the transition from immaturity to maturity, and thence to 
the older stages of growth. The nutritive ratio was nearly 100 per 
cent wider for the old than for the immature tops. 
Canna grown at W T aimea, Hawaii, had substantially the same 
composition as did that grown at the central station. Tubers which 
remained in the ground for two years showed a loss in protein con- 
tent but otherwise were unchanged. 
The feeding value of both the tubers and the tops compares favor- 
ably with that of other starch and forage crops. 
Canna starch is characterized by its exceptionally large grains. 
Morphologically, it is similar to potato starch. Its viscosity is 
greater than that of corn starch but less than that of. potato starch. 
It is thought that edible canna starch has potential possibilities 
both as an edible starch and for commercial uses. It makes quick 
growth, produces heavy yields, and can be harvested at any age 
and during any season, and should therefore lend itself admirably 
to continuous production at minimum cost. When the crop is grown 
on a large scale, the tubers should be produced at a comparatively 
low cost per ton. The starch should be manufactured at excep- 
tionally small cost since it is separated with ease. Although starch 
from edible canna was not produced in Hawaii for industrial purposes 
until 1922, there is no reason why it should not become as popular 
as potato starch, with which it is closely comparable. 
o 
