New YorK AGRICULTURAL EXPERIMENT STATION. 133 
Studies were made on the symptoms of the disease and on the 
biology of the causal organism. Attempts were made to reproduce 
the disease by artificial inoculation with pure cultures, but the re- 
sults were unsatisfactory. In experiments on treatment lime and 
sulphur applied to the soil failed to prevent the disease. It was 
observed that some varieties of sweet corn are much more suscep- 
tible to the disease than are others. Subsequently, this corn wilt 
was studied by Dr. Erwin Smith of the United States Department 
of Agriculture, who described and named the causal organism*® 
and added much to our knowledge of it. 
The only other corn disease studied by the Station is a fungus 
leaf blight® of sweet corn on which brief notes were made in 1806. 
CUCU MBER. 
Scab’® is a disease which produces sunken spots on the fruit and 
stems of cucumbers. It is sometimes quite destructive. The 
earliest studies on cucumber scab were made at this Station™ by 
the botanist, Dr. Arthur, in 1887, shortly before his removal to the 
Indiana Station, where the work was completed.” 
The most important work of the Station on cucumber diseases 
was done during the years 1896-1898, when the value of bordeaux 
mixture as a preventive of downy mildew was demonstrated. On 
Long Island the cucumber pickle industry is of considerable mag- 
nitude. In the early nineties the yield of cucumbers began to drop 
off until by 1896 the average yield was scarcely one-fourth of a 
full crop. The main cause of the reduced yield was the ravages 
ef a fungus disease which causes the leaves to turn yellow and 
die. This disease, downy mildew, made its first appearance in 
the United States in 1889 and soon after became widespread. From 
the apparent success of an experiment in New Jersey" and the 
fact that bordeaux mixture had proven so effective against similar 
diseases of other plants, such as the grape downy mildew, it was 
confidently expected that it would control the new cucumber disease, 

* Originally described under the name Pseudomonas stewarti (Proc. Amer. 
Asso. Ady. Sci. 47:422-426. 1898), and later changed by same author to 
Bacterium stewarti (Bacteria in Relation to Plant Diseases, 1:171. 1905.). 
® Helminthosporium turcicum Pass. Rpt. 15:452 (1806). 
® Cladosporium cucumerinum Ell. & Arth. 
™ Rot. 6¢316 301887). 
"Ind. Sta. Bul. 19:8-to (1880). 
® Peronplasmopara cubensis (B. & C.) Clint. 
aN. J. Sta Rpt for 1895 =304- 
