Nov. 29,1915 
Ash Composition of Upland Rice 
359 
ing the degree of accuracy with which each sample represented, in respect 
to weight and moisture content, the average of all the plants at each 
period. In calculating the probable error, one cylinder of 29 plants was 
taken as a unit. The development of the plants at the different stages 
was as follows: At 18 days the plants were stooling to some extent; at 
73 days they were just about to flower; at 103 days panicles were out, 
but the seeds were only partially formed; at 123 days seeds were fully 
formed and ripe. 
Tabi,3 I.— Weights of the different parts of the upland rice plant analyzed at various 
periods 
Age of plant. 
Dry weight 
of green 
stalks and 
leaves per 
plant'. 
Dry weight 
of withered 
stalks and 
leaves per 
plant. 
Dry weight 
of panicles 
per plant. 
Dry weight of 
whole plant above 
ground per plant. 
Percentage of 
dry matter in 
whole plant 
aboveground. 
Days. 
Gm. 
0.132 
. 581 
4 - 3 8 
11.47 
21. 76 
Gm. 
Gm. 
Gm. 
O. 132 
. 581+0.035 
4 - 38 ±o- 25 
12. 42 ±1. 20 
29.53 ±0.99 
35.46 ±1.90 
18. 7 
20. 2dbO. 08 
14. 6±o. 05 
20. 9±0. 10 
25. 8±o. 99 
36. 2 dzO. 16 
O.fl . 
. 
73 . 
o -95 
4-53 
23 - 34 
i O 
103 . 
123 . 
3 * 2 4 
12. 12 
. 
It will be noted that the percentage of dry matter in the green plant 
did not rise until the plant had begun to form seeds. Previous to this 
time the percentage of dry matter in the plant was somewhat irregular, 
but tended to remain about 20 per cent. The variations in the moisture 
content of the first four samples are so many times the probable error 
of each result that they could not be due to poor sampling. There is 
little doubt that weather conditions affected the amount of moisture 
or dry matter in the green plant during the first four stages of growth, 
while the moisture content of the last two samples was controlled chiefly 
by the physiological changes in the plant—accumulation of carbo¬ 
hydrates and death of old leaves. This seems evident from the records 
of rainfall. During the eight days preceding the cutting of each sample 
the number of days with rain and the total precipitation for the eight 
days were as follows: Previous to the 18-day-old sample, 5 days with 
rain, 2.80 inches; previous to the 26-day-old sample, 1 day with 0.90 
inch; previous to the 48-day-old sample, 6 days with 4.63 inches; and 
previous to the 73-day-old sample, 1 day of rain with a precipitation of 
0.32 inch. The weather was thus relatively wet, dry, wet, dry; and the 
percentages of moisture in the green plant were respectively high, low, 
high, low. 
The ash analyses of the various samples are given in Table II. The 
panicles included the seeds and supporting stems. Withered leaves 
of the 73- and 103-day-old samples were analyzed separately from the 
green leaves and stalks, but no such separation was made for the 123-day- 
