14 
BULLETIN 1484, U. S. DEPARTMENT OF AGRICULTURE 
character of the disease symptoms on the differently treated areas. 
About 73 per cent of the plants in the continuously cropped area 
were deranged and almost sterile. In the adjoining area, previously 
in alfalfa, the plants were larger and much more productive, but a 
considerable number had the terminal buds aborted and, although 
showing no other degenerative symptoms, were classed as diseased. 
The data obtained from three upland cotton fields where fair com- 
parisons could be made are shown in Table 3. In all three fields the 
percentage of crazy-top plants was much higher in the continuous 
cotton areas. 
Table 3. — Comparison of number of crazy-top upland cotton plants in adjacent 
10 ,000-square-foot sections from areas cropped continuously to cotton and adjoining 
areas following alfalfa 
[Field 4 had 100-foot rows; field 5, 200-foot rows; field 6, 600-foot rows] 
Field No. 4 
Field No. 5 
Field No. 6 
Row No. 
Cotton con- 
tinuously 7 
years 
Following 
alfalfa 
Cotton con- 
tinuously 8 
years 
Following 
alfalfa 
Cotton con- 
tinuously 5 
years 
Following 
alfalfa 
Crazy- 
top 
plants 
Nor- 
mal 
plants 
Crazy- 
top 
plants 
Nor- 
mal 
plants 
Crazy- 
top 
plants 
Nor- 
mal 
plants 
Crazy- 
top 
plants 
Nor- 
mal 
plants 
Crazy- 
top 
plants 
Nor- 
mal 
plants 
Crazy- 
top 
plants 
Nor- 
mal 
plants 
1 
26 
10 
20 
25 
22 
32 
19 
21 
35 
25 
26 
46 
37 
38 
31 
40 
30 
33 
21 
33 
29 
31 
35 
46 
41 
45 
34 
25 
32 
39 
58 
36 
51 
55 
34 
45 
32 
33 
43 
40 
43 
44 
33 
27 
25 
23 
35 
30 
41 
28 
28 
29 
37 
39 
34 
22 
37 
30 
31 
45 
37 
27 
23 
35 
6 
5 
7 
12 
10 
5 
3 
6 
6 
6 
5 
9 
13 
15 
7 
14 
42 
39 
39 
29 
34 
47 
36 
21 
36 
32 
40 
42 
15 
25 
45 
30 
76 
91 
84 
89 
98 
83 
108 
104 
87 
101 
85 
84 
85 
101 
89 
96 
26 
28 
19 
15 
20 
23 
9 
18 
17 
21 
19 
17 
13 
13 
25 
29 
7 
16 
14 
9 
23 
13 
7 
10 
17 
9 
13 
14 
12 
12 
35 
59 
62 
64 
63 
93 
69 
95 
76 
97 
72 
73 
84 
67 
106 
192 
109 
101 
102 
1S6 
192 
237 
253 
243 
19 
4 
7 
14 
26 
362 
2 
407 
3 . 
379 
4 
407 
5 . 
372 
6 
7 
8 
9 . 
10 . 
11 
12 
13 ._. 
14 
15 
11 75 
16 
8 
80 
17 
8 27 
18 
13 
8 
6 
6 
4 
7 
4 
5 
5 
6 
7 
5 
5 
7 
7 
31 
38 
42 
42 
43 
42 
43 
47 
47 
43 
42 
38 
42 
46 
40 
19.-. 
20 
21 
22 . .. 
23 
24 
25 
26 . _ 
27 
28 
29 
30 
31 . 
32 
Total 
Percentage. _. 
1,021 
47.8 
1,116 
232 
16.0 
1,215 
1,461 
82.4 
312 
195 
14.3 
1, 164 610 
35.4 
1,111 
70 
3.5 
1,927 
That portion of field 5 which had been in cotton for eight years 
illustrated the most extreme stage of the disorder that was observed 
in the survey. Almost three-fourths of the plants in the entire area 
of 5 acres were seriously deranged, and many exhibited such pro- 
nounced symptoms that the field attracted notice from a distance. 
The typical features were the abnormally tall and spindling main 
