444 OHIO EXPERIMENT STATION: BULLETIN 214 
' Powdery Mildew. The leaves of the oriental sycamore, which is planted 
' largely in Cleveland and other cities, are much disfigured by the powdery 
mildew fungus (Microsphaera alni(?), This was studied by the writer in Cleve- 
‘land in 1909. It was found that younger trees were subject to attack by the 
mildew fungus late in the season, so that a foot or more of thetip of the shoot 
was disfigured by the mildew and many of the leaves were prevented from full 
development. The fungus does not complete its development early, and up to 
November 15th no spore sacs were formed. This leaves moderate doubt as to the 
exact identity of the fungus. It is hoped to hold this mildew in check by spray- 
ing which seems to be necessary on younger trees of the oriental sycamore. 
sg 
i TIMOTHY 
; ‘Anthracnose (Colletotrichum cereale Manns)occurs upon timothy and as al- 
ready noted on blue-grass, orchard-grass, red-top; wheat, rye, etc. The attacks 
‘so, far studied, are confined to the culms and sheaths upon the lower part of the 
stems showing small dark masses of the anthracnose fungus as spots upon them. 
This shows that the timothy is liable to carry over the disease between the wheat 
crops. 
; Bacal Blight of Head. See blue-grass. 
Rust (Puccinia poculiformis (Jacqg.) W) Some seasons this is very preva- 
lent upon timothy resulting in much spotting and premature drying up of the 
foliage. This was true to a notable degree in Ohio in 1908. 
Smut (77lletia striiformis (Westd.) Wint.) attacks the blades of timothy and 
' produces interesting developments in them. As a rule the amount of smut is not 
serious... (See smut of blue-grass). 
TOBACCO 
Bacterial Blight. The same bacterium that attacks potato, egg-plant, etc., 
“at times attacks tobacco plants, especially in the early development. (See wilt). 
'" Bed-Rot. Tobacco plants are often de- 
_ Stroyed by damping-off fungi; at times even the 
- root-rot fungus may be present in the beds. 
Owing to the need to use beds several years in 
succession for plant growing the same fungus 
which gives us trouble in greenhouses is very 
liable to give us trouble here. In the old world 
some of the common damping-off fungi are re- 
ported. With us our particular bed-rot troubles 
are due to Rhizoctonia. For checking this dis- 
ease it seems desirable to treat the tobacco beds 
in. late fall with formalin drench at the rate of 
21-2 to 3 pounds of formalin to 50 gallons of 
water; this to be applied to beds at the rate of 
one gallon per square foot after spading up 
thoroughly and incorporattng all fresh manure 
before the treatment is applied. The beds . 
should also be fairly moist. After this treat- Fig. 93, Tobacco plants showing 
bed-rot, Rhizoctonia. 
ment no stable manure should be applied, 
although mineral fertilizers can be used. Ifthe treatments are delayed till spring 
it will be impossible to sow sooner than two weeks following this drench. (See 
Circular 59, 1906). “ 
