940 
Journal of Agricultural Research 
Vol. XXVIII, No. 9 
VARIETAL DIFFERENCES IN PLANT GROWTH AND LENGTH OF 
ACTIVE GROWING PERIOD 
In 1922 and 1923 measurements of height of the individual plants in the 
25-plant sections of each variety were begun in the last week of June and con¬ 
tinued for 12 weeks, or through the second week of September, covering the 
same period in which the flowering and shedding notes were taken. The average 
height of the plants of each variety at weekly intervals, and the increase in height 
over the previous week, are shown in Table III for 1922 and Table IV for 1923. 
Table III.— Average height in inches of 25 plants of each variety for each week , 
and the increase over the previous week , throughout the fruiting season of 1922 
Date 
Acala 
Durango 
Pima 
Lone Star 
Average 
height 
Average 
increase 
Average 
height 
Average 
increase 
Average 
height 
Average 
increase 
Average 
height 
Average 
increase 
June 26 . 
22.4 
18.2 
July 3. 
27.1 
4.7 
23.1 
4.9 
24.8 
19.9 
10.:. 
30.2 
3.1 
25.9 
2.8 
28.9 
4.1 
23.8 
3.9 
17. 
35.2 
5.0 
31.8 
5.9 
32.6 
3.7 
28.4 
16 
24. . 
40.4 
5.2 
35.9 
11 
35.9 
3.3 
30.7 
2.3 
31. - 
45.9 
5.5 
40.4 
15 
40.3 
14 
31.2 
.5 
Aug. 7. 
61.6 
5.7 
43.3 
2.9 
42.3 
2.0 
31.3 
. 1 
14. 
64.2 
2.6 
43.8 
.5 
43.6 
1.6 
31.4 
.1 
21. . 
55.2 
1.0 
44.3 
. 5 
47.1 
3.2 
31.4 
0 
28 . 
50.0 
.8 
446 
.3 
48.0 
.9 
31.4 
0 
8ept. 4. .. 
66. o 
0 
44.6 
0 
48.0 
0 
31.4 
0 
11 . 
50.0 
0 
416 
0 
48.0 
0 
31.4 
0 
Table IV.— Average height in inches of 25 plants of each variety for each week 3 and 
the increase over the previous week t throughout the fruiting season of 1928 
Date. 
Harts ville 
Durango 
Pima 
Acala 
Mebane 
Lone Star 
Average j 
height 
I Average 
increase 
j 
Average 
height 
Average 
increase 
Average 
height 
Average 
increase 
Average 
height 
Average 
increase 
Average 
height 
Average 
increase 
Average 
height 
Average 
increase 
June 25_ 
17.7 
20.0 
19.3 
19.2 
1&5 
15.8 
July 2.. 
23.5 
5.8 
24.9 
4.9 
24.4 
5.1 
25.0 
5.8 
23.5 
5.0 
20.2 
4.4 
9_ 
29.6 
6.1 
30.6 
5.7 
31.0 
6.6 
30.6 
5.6 
28.4 
4.9 
24.9 
4.7 
16. 
33.6 
4.0 
36.0 
5.4 
36.4 
5.4 
34.7 
4.1 
31.3 
2.9 
27.8 
2.9 
23.... 
36.0 
2.4 
40.1 
4.1 
41.4 
5.0 
36.6 
1.9 
32.4 
1.1 
28.3 
.5 
30_ 
37.0 | 
! l.o 
42.1 
2.0 
46.4 
5.0 
37.8 
1.2 
33.2 
.8 
29.6 
1.3 
Aug. 6__. 
37.3 
.3 
42.7 
.6 
50.4 
4.0 
38.3 
.5 
33.4 
.2 
29.8 
.2 
13. 
37.6 
.6 
42.9 
.2 
54.5 
11 
38.5 
.2 
33.4 
0 
29.8 
0 
20. 
37.8 
.2 
42.9 
0 
57.0 
2.5 
39.0 
.5 
33.4 
0 
29.8 
0 
27. 
38.0 
.2 
42.9 
0 
58.2 
1.2 
39.3 
.3 
33.4 
0 
29.8 
0 
Sept. 3_ 
38.0 
0 
42.9 
0 
58.4 
.2 
39.4 
. 1 
33.4 
0 
29.8 
0 
10 -. 
38.0 
0 
42.9 
0 
58.4 
0 
39.6 
.2 
33.4 
0 
29.8 
0 
It may be seen that in both these years the Durango, Acala, and Pima plants 
had a much longer period of active growth than Lone Star. The comparatively 
short growing period of Lone Star was also noticed in 1920 and 1921. The 
plant growth of Mebane in 1923 was much like Lone Star, although Mebane 
became slightly taller. These two varieties were the only ones which showed a 
decidedly shorter growth period than Pima, although the growing period of 
Durango, in both 1922 and 1923, was intermediate between these two varieties 
and Pima. 
In 1923 the Pima plants continued in active growth for nearly a month after 
all the Upland varieties had practically ceased growing, but in 1922 the Acala 
was planted 12 days later than Pima and the plants continued to grow at nearly 
the same rate as Pima to the end of the season. Acala and Durango in 1923 
ceased rapid growth much earlier than in the previous year, while the growth 
behavior of Pima and Lone Star in 1923 closely resembled their previous per¬ 
formance in 1922. 
