DISEASES OF CULTIVATED PLANTS 395 
in Ohio. In addition we have found to a limited extent, another wilt disease of 
the cucumber which appears to be similar to that described by Dr. Smith. 
(Proc. Am. Ass. Adv. Sci. 1895, p. 190). On watermelons in the South he finds 
a trouble with which ours may be identical. (Bul. 105, p. 222). This latter is 
referable to a species of fungus, a fusarium (/usarium niveum Smith), which 
grows internally in the stem and finally plugs up the water vessels in a manner 
similar to the work of the bacterial wilt. Spraying is unlikely to be beneficial 
for this wilt or for the bacterial one. Preventive measures suggest gathering 
and burning infected vines, and especially waging a successful war against the 
insects; these should prove more or less successful according to thoroughness of 
work. The fusarium wilt calls for rotation of crops. Much may be finally done 
by breeding varieties resistant to wilt. 
CURRANT 
Anthracnose. The anthracnose (Gloeosporium ribis (Lib.) Mont.) of the currant 
has occurred occasionally and will apparently be checked by the same treat- 
ment as given for raspberry anthracnose. 
Cane Blight is a very serious disease whenever stools are attacked by it. 
The fungus (Vectria cinnabarina (Tode) Fr.) survives by its threads in the 
tissues of the stool and upon the death of the canes develops as a bright pink 
mass of the fungus upon dead parts. While spraying may, and surely must, 
keep down the risk of infection, whenever stools show attacks by dying of a part 
of the canes and the development of this fungus these infected stools are doomed 
and should be removed and burned. 
Black-Knot. <A black knot fungus (Plowrightia ribesia Pers.) has been de- 
scribed upon currant, and is always a possibility with us. It attacks the 
branches or stems. 
Dropsy. This disease has been met with. It causes very considerable en- 
largement upon the young stems of the currants, not unlike in appearance the 
enlargements due to crown gall in the peach, except that usually more of the 
stem is involved than in the other case. The trouble appears to be due to physi- 
ological causes and the pruning knife may. aid cultural efforts. 
Fig. 50. Leafof currant attacked by leaf-spot. The dead areas are 
easily seen in the currant leaf but the fungus is difficult to discover. 
