392 OHIO EXPERIMENT STATION: BULLETIN 214 
prevalence of the smut yeast spores in later summer—later. growing parts, for 
example, tassels, brace-roots, ears and sucker shoots, are perhaps more often 
attacked by the smut. The smui spores may be scattered in manure if smutted 
fodder is used, and it seems well proved that manured land yields more smutted 
corn than unmanured. The same may be true of clover sod as compared with 
corn stubble. The reason would exist in the decayed vegetable matter, wherein 
the secondary yeast spores of the smut may grow and then may be carried to the 
corn which becomes thus affected. Treatment of seed corn does not apparently 
reduce the amount of smut. Cutting and burning the smut boils before they have 
burst open would be useful. It is worth while to fight smut by all available 
means. 
COWPEA 
Leaf-Spot. In southern Ohio where these are grown there is danger of the 
leaf-spot (Cercospora). This is not liable to be very serious. 
Wilt. The wilt fungus (Vecosmospora vasinfecta tracheiphila Erw. Sm.) is 
more serious, although at present largely confined to the southern districts. For 
Ohio conditions the practice of growing cowpeas is not of such extent as to 
threaten seriously with this disease. 
CRABAPPLE 
Scab. The same scab which attacts the common cultivated sorts also attacks 
the crabapple, including both fruit and foliage. The remedy is that given under 
apple. 
Rust. The same rust fungus 
(Gymnosporangium macropus Lk.), 
in the cluster cup stage appears on 
the crabapple leaves and fruit as 
well as upon the leaves and fruit of 
apple, and leaves of crataegus. (See 
Apple). 
CROCUS 
Root-Rot. Little study has been 
made with us of the diseases of 
bulbous plants, yet we are liable to 
import those occurring in Europe. 
The common root infesting fungus, 
Rhizoctonia, is one of the determined 
troubles of crocus in France. Micro- 
scopic identification of the trouble 
should be easy owing to the charac- 
ters of the fungus. 
CUCUMBER 
Anthracnose (Colletotrichum 
Fig. 47, Cucumber leaf and stem attacked by Lagenarium (Pass.) Hals.). This 
Anthracnose. The dead areasin the cucumber leaf, fungous disease attacks nearly or 
caused by Anthracnose, are usually larger and more it 1 bi 11 th 
nearly circular in outline than with downy mildew. quite -allcurcur its as Well as ne 
bean. Upon the cucumberin Ohio 
it is apparently more destructive during the earlier season. The fungus may 
be found in the greenhouses at all cultural periods, as well as in the field. It causes 
circular dead spots in the leaves, usually more than one-fourth inch in diameter, 
and likewise elongated brown areas on the stem. (See Bulletin 73, 89 and 105)- 
