832 
Journal of Agricultural Research 
Vol. XXXI, No. 9 
Table II .—Effects of soil temperature on the infection of young Goldcoin wheat 
plants with Ophiobolus graminis 
[These experiments were conducted independently of those in which soil temperature and soil moisture 
were varied simultaneously] 
Experiment 1A « 
Experiment IB b 
Summary« 
Average soil tem¬ 
perature, °C. 
Number of plants 
Leaf-blight rating 
■ 
Tiller-base infec¬ 
tion rating 
Root-infection 
rating | 
Average soil tem¬ 
perature, °C. 
Number of plants 
Leaf-blight rating 
Tiller-base infec¬ 
tion rating 
Root-infection 
rating 
Average soil tem¬ 
perature, °C. 
Leaf-blight rating 
Tiller-base infec¬ 
tion rating 
Root-infection 
rating 
8 
26 
0.0 
0.6 
33.0 
8 
31 
1.6 
13.9 
25.2 
8 
0.8 
7.2 
29.1 
12 
26 
8.3 
32.0 
45.5 
12 
29 
30.4 
42.5 
45.9 
12 
19.3 
37.2 
45.7 
16 
26 
3.2 
28.2 
43.5 
16 
23 
17.3 
42.0 
42.0 
16 
10.2 
35.1 
42.7 
20 
32 
.0 
12.5 
26.0 
20 
31 
2.2 
34.9 
40.3 
20 
1.1 
23.7 
33.1 
24 
26 
.0 
4.5 
7.7 
24 
28 
.0 
5.9 
9.5 
24 
.0 
5.2 
8.6 
28 
26 
.0 
1.9 
3.8 
28 
21 
.0 
7.1 
3.1 
28 
.0 
4.5 
3.4 
32 
13 
.0 
3.8 
.0 
32 
18 
.0 
2.8 
4.6 
32 
.0 
3.3 
2.3 
* Plants grown in soil having a moisture-holding capacity of 67 per cent and containing 56.1 per cent 
moisture; one 6-inch soil can used for each temperature; 35 seeds and 100 grams of inoculum containing the 
Oregon strain of the parasite used in each soil can; started Feb. 14, 1922; ended Mar. 10, 1922. 
h Experiment carried on at the same time and in the same manner as experiment 1A, except that it was not 
ended until Mar. 17, 1922. 
e Average amount of infection at each soil temperature in experiments 1A and IB. 
Table III .—Effects of soil temperature on the infection of young Goldcoin wheat 
plants with Ophiobolus graminis 
[These results are from experiments which were a part of the soil-moisture experiments and comprise all 
of the data obtained in soil of relatively low-water content] 
Experiment 2A° 
Experiment 3A 
b 
Experiment 4A 
e 
Summary d 
! Average soil tem¬ 
perature, °C. 
Number of plants 
Leaf-blight rating 
Tiller-base infec¬ 
tion rating 
Root-infection 
rating 
[ Average soil tem¬ 
perature, ° C. 
Number of plants 
Leaf-blight rating 
Tiller-base infec¬ 
tion rating 
1 Root-infection 
rating 
Average soil tem¬ 
perature, ° C. 
Number of plants 
Leaf-blight rating 
Tiller-base infec¬ 
tion rating 
Root-infection 
rating 
Average soil tem¬ 
perature, ° C. 
Leaf-blight rating 
Tiller-base infec¬ 
tion rating 
Root-infection 
rating 
8 
34 
2.9 
10.7 
75.9 
8 
39 
0.0 
35.9 
56.0 
8 
48 
0.0 
14.5 
38.8 
8 
0.9 
20.3 
56.9 
12 
26 
42.3 
79.4 
84.0 
12 
46 
.0 
65.2 
49.0 
12 
46 
23.8 
55.8' 
80.0 
12 
22.0 
66.8 
71.0 
16 
29 
24.4 
78.1 
69.5 
16 
54 
16.6 
69.7 
68.0 
16 
50 
28.0 
78.6 
81.9 
16 
23.0 
75.4 
73.1 
20 
24 
22.9 
44.4 
69.5 
20 
53 
2.8 
41.5 
38.0 
20 
50 
7.0 
67.3 
70.6 
20 
10.9 
51.1 
59.4 
24 
12 
.0 
2.8 
5.5 
24 
53 
2.8 
40.8 
47.0 
24 
51 
9.8 
38.5 
62.7 
24 
4.2 
27.3 
38.4 
28 
20 
5.0 
.0 
.0 
28 
45 
.0 
6.6 
.0 
28 
43 
.0 
10.0 
16.6 
28 
1.6 
5.5 
5.5 
« Plants grown in soil having a moisture-holding Capacity of 67 per cent and containing 33.8 per cent 
moisture; one 6-inch soil can used for each temperature; 35 seeds and 100 grams of inoculum containing the 
Oregon strain of the parasite used in each soil can; started June 3,1922; ended July 1,1922. 
* Plants grown in soil having a moisture-holding capacity of 53 per cent and containing 33.2 per cent 
moisture; one 8-inch soil can used for each temperature; 60 seeds and 400 grams of inoculum containing the 
Oregon strain of the parasite used in each soil can; started Feb. 21,1923; ended Mar. 14,1923. 
* Plants grown in soil having a moisture-holding capacity of 53 per cent and containing 33.2 per cent 
moisture; one 8-inch soil can used for each temperature; 60 seeds and 200 grams of inoculum containing the 
New York strain of the parasite used in each soil can; started Mar. 31,1923; ended Apr. 20, 1923. 
* Average amount of infection at each soil temperature in experiments 2A, 3A, and 4A, having soil 
moistures of 33.8,33.2 and 33.2 per cent, respectively. 
