88 
Vol. XXI, No. I 
Journal of Agricultural Research 
Table III .—Growth and sap concentration of pruned and unpruned apricot trees (1919), 
with comparison of three environmental factors 
Date. 
Time. 
Evaporation. 
Mean 
daily 
tem¬ 
pera¬ 
ture. 
Water 
added, 
Soil 
mois¬ 
ture. 
Shoots on pruned 
trees. 
Shoots on unpruned 
trees. 
Per 
week. 
Per 
day. 
Mean 
length. 
Incre¬ 
ment 
of 
growth 
during 
preced¬ 
ing 
week. 
Os¬ 
motic 
pres¬ 
sure. 
Mean 
length. 
Incre¬ 
ment 
of 
growth 
during 
preced¬ 
ing 
week. 
Os¬ 
motic 
pres¬ 
sure. 
Acre - 
Per 
Atmos- 
A tmos- 
Days. 
Cc. 
Cc. 
0 F. 
inches. 
cent. 
Cm. 
Cm. 
pheres. 
Cm. 
Cm. 
pheres. 
A r . » 
13 
9 
50 
62 
37 
24 
13. 82 
17 
8 
14. 49 
61 
64 
60 
2 3 
13- 52 
25 
8 
13- 61 
21 
185 
192 
26 
57 
r 0. 82 
73 
13 
11. 72 
29 
4 
13- 4 i 
28 
27 
61 
i 3 * 4 ° 
88 
is 
11. 00 
34 
s 
14 - 52 
38 
65 
102 
14 
11.38 
42 
8 
13. 90 
x 4 . 
21. 
42 
246 
35 
65 
r .72 
9. 18 
113 
11 
11. 60 
50 
8 
15 - 19 
oR 
155 
22 
67 
9 - 4 3 
121 
8 
12. 75 
57 
7 
13 - 97 
Jll 4 
508 
72 
73 
8- 56 
132 
11 
13- 01 
63 
6 
14- 57 
63 
455 
65 
72 
8- 39 
142 
10 
13 - 82 
68 
5 
16. 73 
69 
366 
61 
69 
8.17 
148 
6 
15 - 27 
7 i 
3 
r 7 - 43 
808 
81 
7- 33 
156 
8 
14. 76 
77 
6 
15 - 94 
84 
447 
64 
73 
6. 78 
163 
7 
16. 60 
79 
2 
17. 88 
Re 
5.60 
174 
11 
82 
3 
9. 
78 
177 
3 
15. 87 
83 
1 
19. 77 
75 
i 2. 70 
182 
s 
15 - 77 
84 
1 
20. 96 
112 
79 
7. 22 
186 
4 
18. 51 
85 
1 
21. 81 
no 
69 
6. 02 
190 
4 
14-09 
86 
1 
17- 14 
194 
4 
87 
1 
. 
20. 
133 
483 
69 
79 
i 2. 81 
5 - 48 
197 
3 
16. 38 
88 
1 
19. 50 
334 
48 
77 
7 - 52 
200 
3 
18. 58 
89 
1 
22. 04 
38 
74 
6.05 
203 
3 
17 - 03 
90 
1 
16. 16 
24 . 
168 
350 
50 
74 
i 2.62 
208 
2 
19. 66 
94 
1 
21.94 
R 
l82 
260 
37 
72 
5 - 92 
210 
X 
22. 73 
94 
0 
19. 40 
i 3 * 80 
i 95 
73 
6. 66 
.. 
1 
« r=rain. 
i= irrigation water. 
The evaporation rate was at a maximum in June and July. During 
May the prevailing weather was cloudy, and the evaporation rate was 
thereby diminished. The mean monthly temperatures were as follows: 
April, 6i° F.; May, 65°; June, 74 0 ; July, 76°; August, 75 0 ; and Septem¬ 
ber, 74 0 . 
The soil moisture diminished in quantity as the season advanced, in 
spite of the irrigations. The June irrigation was omitted on account of 
the ripening fruit. The figures show how the moisture content of the 
soil rose after each application of water. 
The growth of the selected shoots on the pruned and on the unpruned 
trees was most rapid in the early part of the season. There were more 
or less distinct cycles of growth in each case, though they were more evi¬ 
dent in the case of the heavily pruned trees. The increments in mean 
length are reduced to a 7-day basis. The mean growing season was ap¬ 
proximately the same for each class of shoots, although the rate of growth 
of the unpruned shoots was very slow after the middle of July. Certain 
