SORGHUM SMUTS AXD VARIETAL RESISTANCE 
49 
In contrast with the results obtained at Columbia the percentages 
of infection noted at Manhattan and Amarillo during the four years 
from 1916 to 1919 showed no such seasonal variation. The varieties 
responded somewhat differently in the different years, but no one 
season stands out markedly as one of exceptionally low or high smut 
infection. An examination of the mean temperature preceding and 
following the seeding dates, as well as the precipitation for the cor- 
responding period, likewise reveals no such marked differences in the 
seasons. The data recorded at Manhattan are presented for com- 
parison in Tables 17 and 18. 
Table 18. — Mean daily temperature and precipitation for seven days preceding 
and seven days following the seedings of sorghum at Manhattan, Kans., in stated 
years 
[T=trace] 
1916 
1917 
1918 
1919 
i 
c-3 
cb 
i 
Seven-day period 
Pi 
S o 
3 
® 
a 
S 
a 
a 
.2 
<0 
So 
a 
Day 
g* 
Day 
3* 
Day 
3 S3 
c3 
Day 
ss 
(3 
a 
a 
a 
a 
a 
fl^ 
a 
<3 
c3 
o 
<a 
o 
% 
2 
^ 
& 
Ph 
fc 
*s 
P-. 
°F. 
In. 
°F. 
In. 
°F. 
Tn. 
°F 
Tn. 
May 11 
60.0 

May 18 
74.5 

May 11 
55.5 

May 16 
60.0 
0.22 
May 12 
53.5 
1.75 
May 19 
76.5 

May 12 
61.0 
.02 
May 17 
55 

May 13 
60.5 
.10 
May 20 
68.5 
.95 
May 13 
58.5 

May 18 
60.0 

Prior to seeding 
May 14 
64.5 
1.67 
May 21 
58.0 
.38 
May 14 
69.5 

May 19 
61.5 
.48 
May 15 
52.0 

May 22 
57. 5 

May 15 
70.5 

May 20 
56 

May 16 
55.5 

May 23 
49.5 

May 16 
75.0 

May 21 
56, 5 

[May 17 
56.0 

May 24 
56.0 
62.9 

1.33 
May 17 
76.0 
66.6 
74.0 

.02 
May 22 
60.0 

Total or average 
57.4 
3.52 

58.4 
.70 
fMay 18 
May 25 
May 18 
May 23 
59.0 
59.0 
0.35 

64.0 

May 19 
61.5 
T 
May 26 
61.5 

May 19 
80.0 

May 24 
70 

May 20 
63.0 
.70 
May 27 
56.0 
.25 
May 20 
70.0 

May 25 
68.0 
T 
After seeding 
{May 21 
65.5 
.69 
May 28 
59.5 

May 21 
80.0 
1.11 
May 26 
71.0 
.71 
May 22 
66.0 
T 
May 29 
64.5 
.24 
May 22 
76.5 
2.15 
May 27 
68.0 
.72 
May 23 
70.0 
.37 
May 30 
64.0 
1.29 
May 23 
60.5 
.10 
May 28 
71,0 
.05 
Ulay 24 
79.5 
66.4 

1.76 
May 31 
63.0 
61.1 

May 24 
76.5 
73.9 

3.36 
May 29 
74.0 
69.4 

Total or average 
2.13 
1.48 
1 The dates of planting were as follows: May 17 and 18, 1916; May 24 and 25, 1917; May 16 and 17, 1918; 
and May 22, 1919. 
GENERAL CONCLUSIONS 
Ten species of smuts have been recorded on sorghum {Holcus sor- 
ghum L.) and the related Johnson grass (Holcus halepensis L.). 
Seven of these species appear to be very local in their distribution: 
Tolyposporiumfilife rum Busse in Tanganyika Territory, Egypt, Meso- 
potamia, and India; T. vollcensiiP. Henn. in Tanganyika Territory; 
Ustilago bulgarica Bubak in Bulgaria; Ustilago sorghicola Speg., near 
La Plata, Argentina; Soros porium ehrenbergii Ktihn, in Cairo, Egypt; 
and Endothlaspis sorgM Sorok., in central Asia. Ustilago sorghicola 
and Endothlaspis sorghi are probably identical with Sphacelotheca 
sorghi (Link) Clinton. The description of Sorosp>ori,um 'ehrenbergii 
agrees fairly well with Sorosporium reilianum (Ktihn) McAlpine, 
but the specimen issued in De Thumen Mycotheca Universalis 
No. 725 is certainly Sphacelotheca sorghi (Link) Clinton. Soro- 
sporium simii Evans has been described on Holcus halepensis from 
