Oct. 2 3t 19x6 Daily Transpiration during Normal Growth Period 
179 
responds very closely with previous determinations of the influence of the 
inclosure on the water requirement. 1 
Table X .—Loss of water per unit of dry matter harvested during the maximum transpi¬ 
ration period, August 2 to 11, IQ14 a 
Dry 
matter. 
Mean daily transpira¬ 
tion Aug. 2-11. 
Hourly 
transpira¬ 
tion during 
Daily loss 
of water 
Crop. 
Actual. 
Per gram 
of dry 
matter. 
midday 
per gram 
of dry 
matter. 
per ton of 
dry matter 
per acre. 
Suda^ grass (in inclosure). 
Grams, 
Kilograms . 
Grams. 
Grams. 
Acre-inches . 
3 QI 
2.68 
8.9 
0.9 
0. 08 
Sudan grass (in open). 
216 
2. 44 
ii- 3 
1. I 
. 10 
Amaranthus.. 
54 
•94 
17.4 
i- 7 
■ 15 
Alfalfa, E23-20-52. 
66 
2.83 
42.9 
4-3 
• 38 
Alfalfa, E23. 
77 
3 - 32 
43 - 1 
4-3 
• 38 
Alfalfa, E23 (in open). 
58 
3.26 
56. 2 
5-6 
• 50 
Alfalfa, 162-98A. 
146 
5 - 29 
36. 2 
3- 6 
• 3 2 
a Mean daily evaporation 12 kgm. per square meter. 
Reference has already been made to the fact that the water require¬ 
ment in 1915 was much lower than in 1914. The daily transpiration 
loss of the small grains during a 10-day period from July 7 to 16, 1915, 
ranged from 9 to 13 gm. per gram of dry matter harvested (Table XI). 
Flax, which has a much higher water requirement than the small grains, 
showed during this period a daily loss of from 17 to 19 gm. of water per 
gram of dry matter harvested. 
Table XI .—Loss of water per unit of dry matter harvested during the maximum transpira¬ 
tion period July 7 to 16 , IQ 1 S 0 
Crop. 
Dry 
matter. 
Mean daily transpira¬ 
tion July 7-16. 
Hourly 
transpira¬ 
tion during 
Daily loss 
of water 
per ton of 
dry matter 
per acre. 
Actual. 
Per gram 
of dry 
matter. 
midday 
per gram 
of dry 
matter. 
Grams. 
Kilograms. 
Grams. 
Grams. 
Acre-inches. 
Wheat, Kubanka. 
209 
2. 05 
9.8 
I. O 
O. 09 
Wheat, Galgalos. 
168 
2. 17 
12. 9 
1-3 
. II 
Wheat, Washington Bluestem. 
215 
2. 41 
II. 2 
I. I 
. IO 
Wheat, Turkestan... 
219 
2. 90 
13. 2 
i- 3 
. 12 
Wheat, Marquis. 
208 
2. 26 
10. 9 
1.1 
. IO 
Wheat, Kubanka. 
267 
2. 46 
9. 2 
•9 
.08 
Wheat, Preston. 
279 
2. 86 
10. 2 
1. 0 
. 09 
Oat, Swedish Select. 
332 
3 - 83 
II. 5 
1. 2 
. IO 
Oat, Burt.. 
233 
3 - 03 
I3.O 
i -3 
. 12 
Barley. 
262 
3 - i 5 
12. O 
1. 2 
. II 
Rye. 
203 
2. 28 
II. 2 
1. 1 
• 10 
Flax, North Dakota (C. I. 13) . 
149 
2. 52 
l6. 9 
1. 7 
• 1 S 
Flax, North Dakota (C. I. 19) . 
186 
3 - 49 
18.8 
1.9 
• 17 
Flax, Smyrna. 
182 
3 * 34 
l8. 4 
1.8 
. 16 
a Mean daily evaporation, 7.3 kgm. per square meter. 
1 Briggs, L. J., and Shantz, H. L. Relative water requirement of plants. In Jour. Agr. Research, v. 3, 
no. 1, p. 1-64, 1 fig. pi. 1-7. 1914. Literature cited, p. 62-63. 
55858°—16 - 3 
