864 
Journal of Agricultural Research voi. xxm, no. « 
relation of date of seeding to the development of seedling- 
blight IN TURKEY WHEAT 
The first sowings of winter wheat in 1920 were made in August when 
the soil temperature was fairly 
high. The fall was unusually 
warm, however, and the mean 
soil temperatures did not drop 
below 12 0 C. during September 
and early October, so that it was 
necessary to continue the seed- 
ings late into October to secure 
the low soil temperatures. All 
of the plots were sown when the 
temperature of the soil was above 
Fig. 13.—Graph showing relation o date of seeding to I2 ° C ' except the JfSt plot, SOWH 
the development of seedling-blight of Turkey wheat in on October 20. The percentage 
1920. The cool soil temperatures of the late fall re- r ._1_ 3 ° 
versed the curves from those of figures 10 and 12. Ol Stand and SOll and SLIT temper" - 
(Summary of figure n.) atures are gj ven i n Tables XIII 
and XIV and are shown graphically in figures 11 and 13. 
Table XIII .—Average soil and air temperatures during germination periods of Turkey 
wheat at Madison t Wis. t in the fall of IQ20 
Duration of germination period. 
Average soil tempera¬ 
tures. 4 inches deep. 
Average air tempera¬ 
tures, 6 inches above soil. 
Dates. 
Num¬ 
ber of 
days. 
Mean. 
Min. 
Max. 
Mean. 
Min. 
Max. 
Aug. 24 to 29. 
Sept. 7 to 13. 
Sept. 23 to Oct. 4. 
Oct. 4 to 18. 
Oct. 20 to Nov. 4. 
6 
7 
12 
9 
16 
° C . 
20. 4 
19. 2 
15-8 
8.2 
° C . 
16.3 
15-4 
12. 3 
14.3 
6.8 
°C. 
25.O 
23*5 
20. 2 
l8. 7 
II -3 
°C. 
14.4 
17. 2 
13-9 
17.4 
9-5 
° C . 
10. O 
11. 6 
8.4 
13. 2 
6. 0 
°C. 
21-5 
23. 1 
20.3 
2 0. 8 
13-7 
Table XIV. —Relation of date of seeding to the development of seeding-blight and winter- 
killing of Turkey wheat at Madison , Wis., in the fall of 1920 
Date of seeding. 
Aver¬ 
age 
num¬ 
ber of 
Average per¬ 
centage of 
stand, fall, 1920. 
Average per¬ 
centage of 
stand, spring, 
1921. 
Average per¬ 
centage of 
winter killing. 
days for 
emer¬ 
gence. 
Control. 
Inocu¬ 
lated. 
Control. 
Inocu¬ 
lated. 
Control. 
Inocu¬ 
lated. 
Aug. 24. 
6 
77.O 
60. O 
68. 0 
48.8 
9.0 
II. 2 
Sept. 7. 
7 
55 - 0 
53 -o 
44*0 
48. 2 
II. O 
4. 8 
Sept. 23. 
12 
83 - 5 . 
49 -S 
5^0 
31. 6 
27-5 
17.9 
Oct. 9. 
9 
92. 0 
67. 0 
49.2 
29. 2 
42. 8 
37-8 
Oct. 20. 
16 
90. 0 
86.0 
71.7 
57-8 
18.3 
28. 2 
