WINTER BLIGHT OF TOMATO. 183 
ate of copper, and fresh seedlings were set in it; but 
these plants also contracted the disease. Just before 
this last treatment was given, a Io-inch pot was filled 
from the soil in the box, and a seedling from the same 
lot as those placed in the box was planted in it. The 
pot was set in the tomato house. This plant showed the 
disease in less than three weeks. The question at once 
arises if the disease was not communicated through the 
air from infected plants, rather than through the soil. 
This I cannot answer, but it is certain that the disease 
travels from plant to plant which stand in separate 
boxes, and whose tops do not touch. Through what 
distance this transfer can take place I do not know. 
We observed it to have occurred through a distance of 
2 or 3 feet, but a plant which stood 15 feet from dis- 
eased plants, but separated from them by a glass parti- 
tion in which two doors stood open, did not take the 
blight. 
All our experiments, therefore, simply lead us to the 
conclusion that the best treatment for this winter blight 
is to remove all diseased plants at once, and if it be- 
comes serious to remove all the plants and soil in the 
house and start anew. They emphasize the importance 
of starting with new plants and fresh soil every fall. 
And all our experience has shown that the disease is 
fatal to success in tomato forcing, for we lost our crop 
in an endeavor to treat it. Since clearing our houses 
thoroughly of this infection, we have never had it again. 
