V. NOTE OK A TOMATO DISEASE. 



S. A. BEACH. 



A peculiar disease of the tomato, the cause of which is not 

 well understood, has occurred in the forcing house at this Sta- 

 tion. Tomatoes which were attacked by what is apparently the 

 same disease have also been found in other greenhouses. Speci- 

 mens of the diseased fruit were furnished Mr. Stewart, the Sta- 

 tion Mycologist, at Jamaica, N. Y., who has prepared from them 

 the following description of the disease: 



This disease has the general characters of the so-called black 

 rot of field grown tomatoes, which attacks the blossom end of the 

 early fruits and which is supposed to be caused by the fungus, 

 Macrosporium. tomato, Cke. It begins as a slightly depressed, 

 circular, brown »pot which gradually enlarges, retaining its cir- 

 cular form, until it frequently coverj^ as mucli as one half of 

 the entire surface of the tomato. See Plate IX. In the great 

 majority of cases the spot originates at the blossom end of the 

 fruit, but it may originate at any point on the fruit. In color, 

 the spots are at first brown; later, they become brownish black 

 or greenish black and are bounded by a conspicuous double ring 

 of light brown. In texture, the diseased tissue is leathery and 

 dry with the surface usually smooth and glassy but sometimes 

 wrinkled and velvety. The diseased portion shrivels so much 

 that the fruit becomes much flattened on that side. The bound- 

 ary line between the healthy and diseased tissue is definitely 

 marked. Inside, the tissues are blackened for a considerable 

 distance below the surface and there is somewhat less than the 

 normal amount of moisture. 



It occurred most frequently on the early fruits of rapidly grow- 

 ing plants but continued to appear to some extent throughout 

 the season. The fruits are attacked in all stages of development, 



•Partial reprint of Bulletin No. 125. 



