Oct. n, 1916 Daily Transpiration during Normal Growth Period 
207 
Table XXII .—Correlation of transpiration of millet , corn, sorghum, and Sudan grass 
with intensity of weather factors and with evaporation 
Plant. 
Year. 
Radiation. 
Tempera¬ 
ture. 
Wet-bulb 
depression. 
Evaporation. 
Wind, 
Shallow 
tank. 
Deep 
tank. 
Millet. Kursk. 
1914 
O. 54±0.07 
0.61 ±0.06 
0.77 ±0.04 
0.68±o* 05 
0.66 ±0.05 
0. 23^0.09 
Do. 
1915 
■ 58 ± .07 
• 63 ± .06 
. io± . 05 
.78± . 04 
• 49 ± .08 
. I9± • 10 
Millet, Siberian. 
1914 
•S 7 ± .06 
.64± .06 
. 78 ± .04 
. 73 ± .04 
.69± .05 
• 3i± .08 
Sorghum, Minnesota 
Amber. 
1914 
.6i± .05 
.64± .05 
• 79 ± .03 
. 7o± . 04 
. 59 ± .05 
.i6± .08 
Do. 
1915 
. 64 db .08 
• 38± .12 
• 57 ± •*© 
•75± -©6 
• 48± .11 
• o7± .14 
Sorghum, Dakota Am- 
ber. 
1914 
• 56± .06 
• 72± .04 
,8i± .03 
• 74 ± *<>4 
.$2± .06 
.I7± .08 
Sudan grass (in inclo- 
sure). 
1914 
* 55 ± -©6 
.84± .03 
• 83 ± .03 
• 93 ± *oi 
• 75 ± *°4 
• 52 ± *©7 
Do. 
191S 
. 64± . 08 
.28 i . 12 
. 64 ± .08 
. 75± .06 
• 37 ± -ii 
• 04 ± .13 
Sudan grass (in open)... 
1914 
• 52± .07 
. 8i± .03 
• 85± .03 
. 82 i .03 
.6od= .06 
• 32± .08 
Com, Northwestern 
Dent. 
1014 
. 8o± .04 
. 71 ± .04 
.8i± .03 
. 79 ± . 03 
.69 h .05 
.28± .08 
Com, Algeria. 
1914 
.62± .06 
• 79 ± .04 
,88± .02 
• 8s± .03 
• 75 ± • ©4 
• 33 ± *©9 
Mean of 1914 co- 
efficients. 
. 60 
* 72 
.82 
.78 
.66 
• 29 
Mean of all coeffi- 
cients. 
60 
.64 
. 77 
• 77 
.60 
• 23 
Square of mean of 
1914 coefficients. 
■36 
•52 
* 67 
.61 
•44 
.08 
Square of mean of 
all coefficients.. 
.36 
.41 
*59 
•59 
•36 
.05 
The dependence of transpiration on the various factors, as expressed 
by the squares of the mean correlation coefficients, are as follows: Radia¬ 
tion, 36 per cent; temperature, 41 per cent; wet-bulb depression, 59 per 
cent; and wind, 5 per cent. The association of transpiration with 
evaporation from the shallow tank is 59 per cent, and from the deep tank 
36 per cent. As in the case of the cereals, the evaporation from the 
shallow tank and the integrated wet-bulb depression show the same 
degree of association with the transpiration. 
Legumes. —The correlations of the transpiration of the legumes 
(Table XXIII) with the various climatic factors and with evaporation 
discloses the same relationships appearing in the other groups. 1 Wet- 
bulb depression and evaporation from the shallow tank gave, as before, the 
highest coefficients. Radiation, temperature, and evaporation (deep 
tank) show a somewhat lower correlation, while wind again shows a low 
correlation. 
The correlation of the transpiration with the intensity of the physical 
factors of the legumes is lower than either group considered above, but 
the different factors stand in about the same relationship. The depend¬ 
ence of transpiration on the several climatic factors and the association 
1 The correlation coefficients between the transpiration 
follows: 
With radiation. 
With temperature. 
With wet-bulb depression.. 
With evaporation (shallow tank). 
With evaporation (deep tank). 
With wind velocity. 
of amaranthus and the weather factors were as 
1914 1915 
. o.40±o.09 o* 69±o.07 
. .4s± .08 . 6o± .09 
. . 6o± .07 .8o± .05 
.56± .06 . s8± .09 
. . 47± .08 .62± .08 
.04± .10 .I 5 ± .14 
