182 
Journal of Agricultural Research 
Vol. VII, No. 4 
the ratio of the weights the mean surface area per pot was computed. 
The area measurements were made at harvest time and include the area 
of matured leaves as well as the fresh leaves and stems. The maximum 
transpiring area is therefore represented in these measurements (Tables 
XIII to XVI). 
Table XIII.— Transpiration per square meter of plant surface during the io-day period 
July y to 16, IQ14 » 
Daily transpiration 
July 7-16. 
Hourly 
transpira¬ 
tion per 
Ratio of 
transpira¬ 
tion per 
square 
meter to 
evaporation 
per square 
meter. 
Crop. 
Plant 
surface. 
Actual. 
Per square 
meter of 
plant 
surface. 
square 
meter of 
plant 
surface 
during 
midday. 
Wheat, Kubanka . 
Sq. meters. 
2. 45 
Kgm. 
4. OO 
Kgm. 
I. 63 
Gm. 
163 
0. 13 
Wheat, Galgalos.. . 
2.68 
4.69 
I- 75 
I 75 
. 14 
Oat, Swedish. 
3 - 42 
4 - 34 
I. 27 
127 
. 10 
Oat, Burt. 
2. 46 
4 -°s 
I. 65 
165 
• 13 
Barley. 
i- 95 
2. 20 
n *3 
IJ 3 
.09 
Rye . 
1. 99 
3-05 
1* 53 
i 53 
. 12 
Millet, Kursk . 
3 - I 5 
2.39 
. 76 
76 
. 06 
Millet, Siberian . : . . 
4. 20 
2. 57 
. 61 
61 
• °5 
Sorghum, Dakota Amber . 
1. 76 
2. 62 
1.49 
149 
. 12 
<* Mean daily evaporations 12.3 kgm. per square meter. Hourly evaporation during midday= 1,230 gm. 
per square meter. 
Table XIV.— Transpiration per square meter of plant surface during the 10-day period 
August 2 to li y igi4 a 
Daily transpiration 
Aug. 2-11. 
Hourly 
transpira¬ 
tion per 
Ratio of 
transpira¬ 
tion per 
square 
meter to 
evaporation 
per square 
meter. 
Crop. 
Plant 
surface. 
Actual. 
Per square 
meter of 
plant 
surface. 
square 
meter of 
plant 
surface 
during 
midday. 
Sudan grass (in inclosure). 
Sq. meters. 
3 * 2 7 
Kgm. 
2.68 
Kgm. 
0. 82 
Gm. 
82 
0.07 
Sudan grass (in open). 
I. 90 
2.44 
1.28 
128 
. II 
Amaranthus. 
.67 
•94 
I. 40 
140 
. 12 
Alfalfa, E23-20-52.. 
I. 71 
2.83 
i. 66 
166 
. 14 
Alfalfa, E23. 
2. 08 
3 * 3 2 
i *59 
*59 
•13 
Alfalfa, E23 (in open). 
•95 
3.26 
3 * 43 
343 
.29 
Alfalfa, 162-98 A. 
3*37 
5 - 29 
i *57 
157 
•13 
a Mean daily evaporation** 12 kgm. per square meter. Hourly evaporation during midday** 1,200 gm. 
per square meter. 
