Some Tbodbles of "Winter Tomatoes. 221 



bonate of copper applied to the soil. The plants were somewhat 

 diseased when the treatment was given. The disease progTessed 

 without check. One plant died, an.d a healthy plant was set in 

 its place. This plant — which is conspicuous in the foreground of 

 the illustration — was remarkably strong and vigorous for a period 

 of three ^^'eelvS, when it contracted the disease. In the meantime 

 another plant — shown in the background — died from the disease. 

 Late in the winter the remaining plants were removed from the 

 box, the soil was again treated with ammoniacal carbonate of 

 copper and fresh seedlings were set in it; but these plants also 

 contracted the disease. Just before this last treatment was given 

 a ten-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. Thi's I can not 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 

 observ^ed it to have occurred through a distance of two or three 

 feet, but a plant which stood fifteen feet from diseased plants, but 

 separated from them by a glass partition in which two doors stood 

 open, did not take the blight. It is still possible that we may 

 find a snccessful treatment for diseased soil, if all affected plants 

 can fii*st be removed from the house. 



All oiir experiments, therefore, simply lead us to the conclu- 

 sion that the best treatment for this winter bUght is tO' remove all 

 diseased plants at once, and if it becomes serious to remove all 

 the plants and soil in the house and start anew. They empha- 

 size 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. 



2. Common Blight (Cladosporium fulvum), — The blight which 

 is oftenest associated with the forcing of tomatoes appears as 

 cinnamon brown spots on the under surfaces of the leaves, as 



