DISEASES OF HOUSE TOMATOES. LG 
it is almost impossible to thoroughly eradicate them. 
The root-gall, caused by a nematode worm (Hefero- 
dera radicicola), often does great damage in tomato 
houses (Fig. 29, page 87). The treatment is to use only 
soil which has been thoroughly frozen, as explained on 
page 85. After cleaning the benches of infected soil, it is 
well to wash them in strong lye.* 
Diseases.— We have had serious difficulty with dis- 
eases. The rot of the fruit has been one of the worst, 
and this has appeared chiefly upon the first fruits. This 
disease appears to originate as a physiological trouble (not 
from the attacks of fungi, as commonly supposed), and the 
proper treatment is to keep the house dry and sweet. 
The to- 
mato blight 
or rust ( Cla- 
dos porium 
fulvum) is 
frequent in 
to m-a@ t:o 
houses, par- 
ticularly to- 
Wia fds 
spring. Fig. 
60 shows the 
patches of 
the fungus at the points marked a. It causes rusty patches 
upon the leaf, and the foliage soon shrivels and dies. It 
is very likely that the disease may be brought into the 
house in soil upon which diseased plants have been 
grown. If it appears, the plants should be thoroughly 
sprayed at once with Bordeaux mixture. 
The dropsy or cedema of the tomato is a physiologi- 
cal disease produced in house tomatoes by a too succu- 
60. Tomato blight (Cladosporium fulvum). 
*For a fuller account of the root-gall on house tomatoes, see Bulle- 
tin 43, Cornell Exp. Sta. (Sept. 1892). 
