Feb. 16,1934 
Physiological Studies on Flag Smut of Wheat 
447 
in the field. Tisdale, Dungan, and Leighty ( 15) give the average per¬ 
centage of infection for the different varieties grown in the field for a 
number of years. The same strains of some of the varieties grown by 
them in the field also were grown in the greenhouse by the writer. The 
average percentages of infected plants grown under both field and green¬ 
house conditions are given in Table XI. 
Table XI.— Percentage of infection of the same strains of wheat, spelt and earner inocu¬ 
lated with Urocystis tritici and grown in the field at Granite City, III., and in the green 
house at Arlington Experiment Farm, Rosslyn, Va., in the same three years, 1919, 1920, 
and 1921 
; 
| 
Field. i 
i 
Greenhouse. 
Variety. 
Source or j 
C. I. No. 1 
1 
1 
Average 
infection. 
Number of 
years 
grown. 
Average 
infection. 
Number of 
years 
grown. 
WHEAT. 
Pinna , ,. 
j 
180 
Per cent, j 
1.6 i 
| 
2 
j 
Per cent, j 
3-4 
2 
Tlawson .. 
6161 
5-8 1 
2 
1-7 
2 
Fill paster ... 
6162 
1.2 j 
3 
0 
3 
Fultz . 
3 S 9 8 
5579 
2.5 | 
2 
58-4 ! 
3 
Gipsy. 
•7 ! 
3 
2.9 i 
2 
Goens. 
342 8 
5957 
2 -5 ! 
2 
6.6 | 
2 
TJorvoct fYlIPPTl . 
24.9 ; 
3 
89.9 
3 
AJLCll VtOU v^/ , • * • * •••••*• 
Do . 
Ill. 
18.1 
1 
75-6 
! 1 
Hussar . 
4843 
0 ! 
1 
O 
1 
Illini Chief . 
5406 
5608 
5146 
Wn. 1092 
3 *° 
2 
O 
1 3 
Tones Fife . 
4.8 
2 
7 6 -3 
2 
Tfanred . 
2-5 
3 
2.2 
2 
Martin ... 
0 
1 
O 
1 
Mealy. 
5824 
5879 
5880 
3489 
I 9 I 5 
559 6 
5976 
5582 
3527 
1773 
7-3 
2 
10.6 
| 3 
P-1066.... 
•3 
2 
0 
! 1 
i 
P-1068. 
o 
2 
0 
; 1 
Poole. 
! Trace. 
! 3 
0 
1 •> 
! 0 
Pnmlestraw . 
9-7 
2 
66.1 
i 1 
Perl Mav . 
1.0 
2 
0 
! 3 
Perl T?opV . 
.2 
3 
0 
I 3 
Fed Wave . 
Trace. 
i 
72.9 
! 1 
1 
Treadwell . 
2.8 
3 
0 
2 
SPELT. 
Alstronm . 
0 
! 
i 
l 
i 
| 2 
j 
i 
j 10.0 
1 
emmer. 
j 
i 
1 
! 
1 
"Rlaelr Winter . 
2337 
1 0 
j 2 
0 
1 
I 
j 
Man y of the varieties which were free from infection when grown 
in the greenhouse were reported as being slightly susceptible in the field. 
On the other hand, one of the most susceptible varieties, Harvest Queen 
(Red Cross), had a three-year average infection of 24.9 per cent in the 
field. The same strain of Harvest Queen grown m the greenhouse dunng 
the same three years had an average infection of 89.9 per cent, or a differ¬ 
ence of 6 s per cent. Other varieties which showed great differences in 
percentages of infection were Fultz, Jones Fife, Purplestraw, and Red 
Wave. The fact that the area quarantined for flag smut is located 
in the winter-wheat section has precluded any experiments on varietal 
resistance of spring wheat in the field. 
