Au*. as, 19*3 
Ophiobolus cariceti and Weakened Plants 
355 
In order to ascertain any difference in varietal susceptibility in wheat, 
as well as the pathogenicity of Ophiobolus on Festuca elatior y each plot 
was divided into four equal parts, sown to grass and wheat. One of these 
parts in each acre plot was sown to Festuca, another to Pool’s Mar¬ 
velous (wheat which had been grown on this field the year previous), 
another to Alabama Blue Stem, and the remaining equal part of each 
plot to Marvelous. 
The plots were visited 7 frequently and notes kept of their appearance 
at different times. The first marked differences were noted on December 
10, 1921. Among the notes taken on that day are the following: Manure 
plot, plants 4 to 5 inches tall and of good color; stand is good, Alabama 
Blue Stem showing up the best. Lime plot, much like the untreated 
plot; stand is poor, plants are off color and lacking in vigor. Commercial 
fertilizer plot, stand is excellent; the plants are of good color and vigor¬ 
ous. Untreated plot, stand poor; plants are undersized, spindling, and 
off color. 
From December on through the winter and spring the same differences 
prevailed. On April 18, when the plots were photographed (see PI. 5, 
A and B)*, those treated with manure and commercial fertilizer showed 
excellent growth as compared with the untreated and limed plots. A 
few of the plants in the manure as well as in the commercial fertilizer 
plots appeared undersized, but it was impossible to tell whether this 
was due to improper distribution of the manure and fertilizer in the 
vicinity of such plants, or to some other cause. On June 8, when the 
heads were almost mature, it was possible to make actual counts of the 
number of plants which clearly possessed symptoms of Ophiobolus. The 
amount of infection was as follows: Untreated, 80 per cent; manure, 45 
per cent; commercial fertilizer, 7 per cent; lime, 95 per cent. When the 
wheat was harvested and threshed the following yields were obtained: 
Variety. 
Yield from 
untreated 
plot. 
Yield from 
plot treated 
with 
manure. 
Yield from 
plot treated 
with com¬ 
mercial 
fertilizer. 
Pool’s Marvelous... 
Bushels . 
0.8 
Bushels. 
V 0 
Bushels . 
5*5 
5- 0 
Alabama Blue Stem. 
I. 2 
5*3 
2.0 
Marvelous. 
1. 1 
3*3 
The lime plot was a total failure; the plants were so stunted and the 
stand so poor that it was considered useless to attempt to harvest the 
crop. The figures shown above represent actual yields of each one- 
fourth-acre plot. The one-fourth acre of Festuca which was included in 
each plot is not figured, since the stand on all was poor, weeds having 
taken possession of the soil before the plants had made any growth. 
Figuring on the basis of yield per acre and averaging the three varieties, the 
untreated plot yielded 4 bushels, manure plot 14.3 bushels, and commercial 
fertilizer 18.4 bushels (PI. 5). The yield from the manure plot is above 
the average for the State, while that from the commercial fertilizer was 
considered so phenomenal by the farmers in the vicinity that it attracted 
t The writers are greatly indebted to Mr. R. R. Crawford, who spent much of his time in seeing that 
these experiments were properly carried out, and in keeping careful notes on the various plots. 
