0 Nebraska Experiment Station Research Bulletin 18 
<o .h © bfl 5 - 
SP ot * 
^ x £ 
^ a £ 
© 
£ 
© 
© 
— 
« 4 H 
c£ 
X 
0 
■4—1 ■ 
f-i 
r o 
© 
[© 
r+ 
, 1 
© 
£ 
© 
© 
3 
X 
© .i-i 
C/2 © 
2 © 
Tl 
? 
bJD ^ 
!3 O 
o 
c3 
© © 
q jd 
01 3 
«+h *+^ 
Q 
M 
*02 d 
© d 
-3 o 
© ^ 
© <3 
02 © 
© £ 
-2 2 
r- 
©• 
s 
X 
• ‘ 
a: r 
© 
w 
J_l 
© 
f 
© 
j , 
X 
© 
r^* 
© 
/. 
O 
Q 
Z2 
*■3 
Mi 
X 
S3 
X 
. ' 
'*“» © 53 
S 
tJD^ £ 
Sobfig 
ai: 
^ © 
© 
£ 02 
02 it. 
§.« 
X © 
— I © 
-5 x 
3 O 
-*— > ©3 
© -u> 
i c3 
X 
s . 
'3 SS 
© hH 
C3 o 
g^© 
o^3 
o ^ H 
O 02 I 
G 
* 
A 
H 
oa 52 
<u — 
S-I 4-> 
rt O ai 
Q « 
.22 
c '£ 
.2 ri5 CO 
•P O^°0 
ite-d^ 
PQ 
.22 
^ © h-— 
.2J«W 
■u o ® 00 
•If d« 
PQ 
c 
© 
^ d 
2 2 
O 
+3 3 i 2 < 
22^3 
§2 I 
rt co o 
"0 o _ 
O »f-H C 
w VI O 
3 52 '-+3 
C3 03 o 
« £ © 
O £ — ' 
T) O «1 
C D 
'£ ^ ’> 
1 .s 
. < v 
V = 2 T 3 
W^S © 
® © QJ 
© . o 
^ >» © 
r_, b? © 
t -1 O s-, 
aJ CM 
8« 
© £3 . 
C o® 
X xH 
aJ^J\ 
© .0 CO 
£* • C/2 
O C 
-e o 
TJ <J 
© . 
— © 
15 © 
c ^ 
© © 
m 
a 
© 
• C 
® ^ 
© 
■g"®ei| 
° |\ © 
rt^.2, 
2 2 ~ c c 
CQCQ-rt ° - ^ 
CJ* C 
• . CS.W’C 
OO co © 
.-£ .t 2 © b 
CD xf CM CD 
00 00 00 00 
X I MIX 
X X XXX X 
X X XXX X 
X X XXX X 
X X XXX X 
»-h CM CO xf tO CD 
