Nov. 1,1925 
Ophiobolus graminis and TaTce-All of Wheat 
819 
Table VIII. — Period of susceptibility of California Club wheat plants to the attack 
by Ophiobolus graminis in Experiments I and II 
[The seed was sown at one time and the inoculum was applied at intervals during the growth of the plants. 
Controls were uninoculated] 
Number of diseased plants 
Number of days after plant¬ 
ing before inoculum or 
media was added 
Same day 
Do... 
14. 
14. 
28 . 
3 = 
42. 
56 . 
56 . 
70 . 
70 . 
Treatment 
of plants 
Inoculated. 
Control— 
Inoculated. 
Control— 
Inoculated. 
Control_ 
Inoculated. 
Control— 
Inoculated. 
Control.... 
Inoculated. 
Control.—. 
Experiment I (out of doors) 
Experiment II (in greenhouse) 
Number 
Number 
Number 
Number 
Number 
of plants 
of plants 
Number 
of plants 
of plants 
of plants 
badly 
slightly 
of plants 
badly 
slightly 
diseased 
diseased 
diseased 
diseased 
20 
20 
0 
7 
7 
0 
10 
0 
0 
7 
0 
0 
20 
0 
20 
7 
0 
7 
10 
0 
0 
7 
0 
0 
20 
0 
20 
7 
0 
0 
10 
0 
0 
7 
0 
7 
20 
0 
20 
(°) 
10 
0 
0 
7 
0 
0 
20 
0 
20 
7 
0 
7 
10 
0 
0 
7 
0 
0 
*20 
0 
20 
10 
0 
0 
« Plants destroyed by rats. b Plants were in bloom. 
In Experiments III and IV, Goldcoin seed was sown at intervals 
of two weeks. The inoculations were made at the time of the last 
planting. As in Experiments I and II, all the inoculated plants be¬ 
came diseased, while the control plants remained healthy, as indi¬ 
cated in Table IX. The plants from seed sown at the time of in¬ 
oculation developed the disease first and showed the most severe 
injury. Many of them died in the seedling stage, and none of them 
matured seed. Likewise the plants that were 2 weeks old when in¬ 
oculated were attacked in a similar manner, but to a less degree. 
However, the plants that were older when inoculated did not show 
the effects of the disease until later. 
Table IX. — Period of susceptibility of Goldcoin wheat to attack by Ophiobolus 
graminis in Experiments III and IV 
(Plants grown under greenhouse conditions, in soil held near 18° C. The seed was sown at intervals and 
the inoculations were made at the time of the last planting. Controls were not inoculated] 
i 
Number of diseased plants 
Age of plants when inoc¬ 
ulum or mediaVaS added 
(days) 
Treatment 
of plants 
Experiment III 
Experiment IV 
Plants grown from June 27 
to Sept. 12 
Plants grown from Sept. 7 
to Dec. 6 
Number 
Number of plants 
of plants badly 
diseased 
Number 
of plants Number 
slightly of plants 
diseased 
Number 
of plants 
badly 
diseased 
Number 
of plants 
slightly 
diseased 
Just planted. 
Do. 
14... 
14_ 
28_ 
28.. 
42_: 
42_ 
Inoculated .. 
Control. 
Inoculated.. 
Control. 
Inoculated _. 
Control_ 
Inoculated.. 
Control_ 
30 
10 
30 
10 
30 
10 
0 
0 
30 
0 
30 
0 
0 
0 
30 
0 
30 
0 
30 
10 
30 
10 
30 
10 
30 
10 
30 
0 
15 
0 
0 
0 
0 
0 
0 
0 
15 
0 
30 
0 
30 
0 
CEREAL INVESTIGATIONS. 
