DISEASES OF CULTIVATED PLANTS 447 
‘Hartford, Conn., notably at Litchfield, this 
disease has been troublesome on certain soils; 
the same fungus has been found upon ‘catalpa 
seedlings in Ohio. It is better known as attack- 
ing the roots of violets. In all cases there is a 
blackening and rotting of the roots of seedling 
plants where they are attacked. Thorough 
steaming of the bed soil should be practiced 
where this trouble comes in, to avoid transplant- 
ing it tothe field. In the field as has recently 
been pointed out ‘by Gilbert and Briggs, the 
check on growth of tobacco is much. greater in 
wet seasons than in dry ones. Apparently 
attention must be given to the drainage of the 
land which becomes infected if this is to be 
continued in tobacco. 
Wilt (Bacterium solanacearum Erw. Smith) 
has occurred frequently in North Carolina and 
has more recently been sent to the writer from 
shade plantations in Florida where considerable 
Fig. 96. The fungus of tobacco root- acreage was lost in1908, due to infection through 
rot (Thielavia basicola Zopt.). Camera the soil. This bacterial disease has recently 
lucidia drawing or the fungus as it heen investigated by Stevens and others, but it 
ia Birt Saeaeh AE ae ee is not believed any methods of treatment will 
spores. All magnified 565 diameters. evade the necessity for rotation. (See Bulletin 
From a drawing by J: M. VanHook. 156 also potato wilt.) 
White Speck has been studied in North 
Carolina and attributed toa specific fungus (Macrosporum Tobacinum E. & E.) 
Another fungus of the same genus has been accredited in the same state as the 
cause of brown-rot, but these have not been studied in Ohio. 
TOMATO 
Anthracnose (Colletotrichum phomoides (Sacc.) Chest.) occurs occasionally 
upon tomato fruits, causing small depressed spots in them, The same fungus 
may at times attack other parts of the plant. This disease seems to be checked 
by the use of Bordeaux mixture. (See also Collar disease). 
Bacterial Blight of the tomato, egg-plant and potato has already been men- 
tioned. It was destructive at Mt. Carmel, near Cincinnati, in 1896 (B. 73). It 
has since been locally.destructive. It causes sudden blighting and decaying of 
the stems and branches attacked. Spraying has as yet proved useless for the 
blight. Preventive measures recommended, include fighting insects, early 
removal of diseased vines, choice of fresh land not previously in potatoes or egg- 
plants, and tomato seed from healthy sources. To date this disease has been 
less destructive than the leaf-spot. 
Collar Disease Vermicularia sp. Recently a peculiar collar disease of fall 
greenhouse tomatoes has come under study. In this case the symptoms were ab- 
normal leaf development, after the manner of mosaic disease by artificial inoc- 
ulation. The collar trouble was quite noticeable. 
The case under study occurred in houses that appeared to be over-watered. 
The plants set very little fruit and were not profitable. The root system appear- 
ed to be normally developed except the adventitious whorl of roots near the sur- 
face. Between these upper roots and the root crown below, thecollar of the plant 
