DISEASES OF CULTIVATED PLANTS 
453 
upon other cereals increases the danger of its being carried over in rotation. (See 
tye, oats, timothy, also Bulletin 203.) 
Le os 
of the plants; on the right normal healthy kernels of wheat of the same 
variety. From Bulletin 203. 
Blade-Spot or Leaf-Spotting has occurred upon wheat in considerable extent 
in Station plots during the last year or two. Small areas were killed by the 
fungus and this leads to somewhat premature dying of the leaves This leaf dis- 
ease calis for further investigations. 
Grain Diseases. It must be remembered that an- 
thracnose and scab are bothin a sense grain troubles. 
They cause shriveling and loss of quality in the 
grain. In addition afungus (4/teraria sp.) causing 
dark spots in wheat kernels has been found by this 
department. Scab must also be included here since 
the parasite attacks the wheat kernels. 
Powdery Mildew. This whitish fungus (Zrysiphe 
gramiuis DC.) also appears upon leaves of wheat 
plants. Usually it is of small importance in Ohio 
but of much interest. 
It attacks wheat both in pot cultures under glass 
and in outdoor growth. In both cultures the conidial 
development of the fungus is very troublesome invad- 
ing the older leaves and causing prematuredeath. In 
the field the consequences are usually not studied, 
but the perithecia of the fungus are often found upon 
straw blades and other parts that have been invaded. 
It is clear that the fungus cannot be beneficiaFto the 
development of the grain in attacked plants. 
Scab. Thescab disease (Fusarium roseum Lk) 
has been again investigated and the results published 
in Bulletin No. 203. It has been found that the same 
scab fungus attacks also rye, emmer, oats ard spelt, 
producing the various effects upon these grains. On 
all attacked heads in wheat the portion diseased 
shows reddish or pink covering with the fungus and 
the part of the spike above this is killed. Of course, 
all kernels contained in that part are much shriveled 
and are commonly invaded by the scab fungus. In  gttacked by scab. 
Fig. 103. Wheat spike 
The upper 
addition a recent study showed that many various portion of the head isshrunken 
sized kernels of wheat are infested with this fungus nd has been killed by the pink 
internally, although still capable of starting to grow foneus. 
and making a new plant. Investigations made in 
