52 
Journal of Agricultural Research 
Vol. XXX, No. 1 
of the kernels disarticulating by fract¬ 
ure had abundant midlength basal 
hairs, while 74 per cent of them were 
without basal hairs. As might be ex¬ 
pected, it is very unusual for kernels 
of Burt oat to have abundant mid¬ 
length basal hairs in the absence of 
the basal cavity. 
A very high degree of association 
is evident between spikelet disarticu¬ 
lation by abscission (presence of basal 
' cavity) and presence of basal hairs 
(0=0.909 ±0.001). Abundant basal 
hairs occur most frequently on kernels 
paving the prominent basal cavity 
which is characteristic of varieties of 
Avena byzantina. 
SPIKELET DISARTICULATION AND AWNS 
The summarized data on the correla¬ 
tion between spikelet disarticulation 
and awns for all strains are presented 
in Table XIII. As in the cases previ¬ 
ously considered, in determining the 
value of Q f the semiabscission and 
abscission spikelet disjunction classes 
w$re combined. The twisted and the 
nontwisted long and short classes of 
awns also were all combined in the 
class “awns present,” which was con¬ 
trasted with the “awns absent” class, 
according to the following scheme: 
Spikelet disarticulation 
Awns 
by— 
Present 
Absent 
Abscission_ _ 
}■ 4,570 
373 
Semiabscission__ 
Fracture... 
2,371 
4, 768 
Q=0.922±0.0009 
It is evident that high correlation 
exists between spikelet disarticulation 
by abscission and semiabscission (pres¬ 
ence of a basal cavity) and the pres¬ 
ence of awns. It is evident also that 
correlation exists between the absence 
of awns and spikelet disarticulation by 
fracture (absence of a basal cavity). 
These conditions are associated in about 
67 per cent of the cases. There was 
a much higher percentage of fractur¬ 
ing kernels which bore long awns than 
of those disarticulating by abscission 
which lacked awns. 
Table XIII.— Data on association of spikelet disarticulation and awns in a strains 
of Burt oat grown at the Kansas Agricultural Experiment Station in 1920 
# 
Number of kernels with awns— 
Percentage of kernels with awns— 
Strain number and kind of spikelet 
disarticulation in kernels 
Twisted 
Nontwisted 
Absent 
Twisted 
Nontwisted 
Absent 
Long 
Short 
Long 
Short 
Kansas No. 5020: 
Abscission... 
0 
127 
81 
1 
0 
60.8 
38.7 
32.1 
0.5 
15.9 
Semiabscission.... 
13 
193 
127 
63 
3.3 
48.7 
, 'Fracture.. 
55 
259 
120 
604 
5.3 
24.9 
11.6 
58.2 
Kansas No. 5211: 
Abscission_1.___. 
1 
543 
246 
9 
. l 
68.0 
30.8 
1.1 
Semiabscission__ 
35 
164 
159 
74 
8.1 
38.0 
36.8 
17.1 
Fracture...... 
187 
218 
77 
346 
22.6 
26.3 
9.3 
41.8 
Kansas No. 5219: 
Abscission.... 
0 
509 
221 
7 
* 
0 
69.1 
30.0 
.9 
Semiabscission_ 
23 
457 
249 
39 
3. 0 
59. 5 
32.4 
5.1 
Fracture_i__ 
71 
73 
29 
226 
17.8 
18.3 
7.3 
56.6 
Kansas No. 5220: 
Abscission___ 
5 
48 
46 
2 
5.0 
47. 5 
45.5 
2.0 
Semiabscission___L__ 
31 
61 
34 
43 
18. 3 
36.1 
20.1 
25.5 
Fracture..... 
62 
109 
101 
337 
10.2 
17.9 
16.6 
55.3 
Kansas No. 6004: 
Semiabscission... 
1 
13 
2 
2 
5.6 
72. 2 
11.1 
11.1 
Fracture... 
66 
58 
10 
785 
7.2 
6.3 
1.1 
85.4 
Kansas No. 6052: 
Semiabscission_ 
7 
9 
3 
2 
33.3 
42.9 
1C 3 
9. 5 
Fracture..... 
181 
214 
70 
935 
12.9 
15.3 
5.0 
66.8 
Kansas No. 6076: 
Semiabscission_• 
19 
29 
16 
26 
21.1 
32.2 
17.8 
28.9 
Fracture_ 
7 
55 
20 
823 
.8 
6.1 
2.2 
90.9 
Kansas No. 6090: 
Abscission..... 
0 
209 
129 
9 
0 
60.2 
37.2 
2.6 
Semiabscission.... 
0 
173 ^ 
173 
61 
0 
42.5 
42.5 
15.0 
Fracture_____ 
24 
44 
33 
506 
4.0 
7.2 
5.4 
83.4 
Kansas No. 6094: 
Abscission__ 
0 
124 
54 
0 
0 
69. 7 
30. 3 
0 
Semiabscission_ 
131 
75 
30 
35 
48.3 
27. 7 
11.1 
12.9 
Fracture___ 
173 
35 
20 
206 
39.8 
8.1 
4.6 
47.5 
All strains: 
Abscission_ 
6 
1,560 
777 
28 
.2 
65.8 
32.8 
1.2 
Semiabscission_ 
260 
1,174 
793 
345 
10.1 
45.7 
30.8 
13.4 
Fracture_ 
826 
1,065 
480 
4,768 
11.6 
14.9 
6.7 
66.8 
Q*=*0.922±0.009 
