CARBOHYDRATE METABOLISM AND GROWTH IN EDIBLE (ANNA 25 
vigorous growth. A representative hill from each plat was dug four 
and one-half months after planting for determination of sugar. Table 
8 shows the difference in the sugars of hills from the two plat-. 
Table 8. — Sugars in 4 l /2-months-old canna plant* grown on irrigated and 
uuirrigatcd plats in station field 26 B 
IRRIGATED PLAT 
6 
Sucrose in sap 
Hexoses in sap 
Total sugars in sap 
1 
Genera- 
tion 
Stage of maturity 
Root- 
stock 
Stem 
Root- 
stock 
Stem 
Root- 
stock 
• 
Stem 
3 
4 
Firs; .... 
Second 
Young Group 2 
Old Group 3a ... 
P(r cent 
2.91 
2.69 
1.70 
1.44 
Per cent 
0.51 
.47 
.29 
Per cent 
0.20 
.33 
.32 
.51 
Per cent 
0.94 
1.25 
.46 
Per cent 
3. 11 
3. 02 
2. 02 
, 8 , 
Per cent 
1.45 
1.72 
5 Third... 
6 Fourth 
Medium Group 3a 
Group 3b (spike) 
.75 
UNIRRIGATED PLAT 
1 First... 
2 Second. 
Medium Group 3a 
Young Group 3a .. 
1.32 
1.26 
0.37 
.33 
0.26 
.09 
0.31 
1.58 
1.35 
The sucrose content of the rootstocks of the irrigated field was 
practically double that of the unirrigated, whereas the hexoses were 
not appreciably higher except for the youngest rootstock. Likewise, 
the hexoses of the stems from the irrigated field were much higher 
than those from the unirrigated and the percentage of sucrose was 
only slightly greater. In the irrigated field the hexoses of the stems 
great!} 7 surpassed the sucrose, whereas the reverse was true of the 
unirrigated field. The results point strongly to the observations 
previously noted that the hexoses of the stem and the sucrose of the 
rootstock are measures of the rate of translocation of sugars and 
storage of starch. 
EFFECT OF IRRIGATING PLANTS STUNTED BY DROUGHT 
Low results were obtained in an analysis of plants from a hill of 
canna from station field 32C, which three months previously showed 
a high sugar content (see Table 7, hill 3), but which had subsequently 
been subjected to a hot, dry period. To determine whether the 
severely stunted field would resume growth, with the production of 
good-sized rootstocks, a part of the field was irrigated every fifth day 
for a period of two months, when the sugars were determined in plants 
from both irrigated and unirrigated parts. Field 26A, on which the 
plants had to a considerable extent matured before the drought set in 
(Table 7, hill 2), was also included in the study. Table 9 gives the 
condensed results of analyses made from time to time, the average 
composition of the entire hill being given in each instance. It fur- 
ther gives, for the sake of comparison, the average sugar content of a 
hill taken from each field during the period of optimum growth. 
