371 



Reprinted from Bulletin of the Torre y Botanical Club, Vol. XVIII, No. 12, Dec. 1891.) 



Notes on Three New or Noteworthy Diseases of Plants. 



By F. D. Chester. 



During the work of the past summer my attention has been 

 called to three diseases of cultivated plants, caused by fungi, 

 which are apparently new. 



A brief description of them will be given here, while a fuller 

 account, with figures, will be reserved for one of the regular pub- 

 lications of the Experiment Station. 



Anthracnose of the Tomato. 



This disease appeared during the past summer upon the 

 grounds of the Experiment Station, where it has caused a con- 

 siderable destruction of fruit. 



So far as observed it does not affect the green tomato, but 

 rather at the point when it just begins to color, and from that on 

 to complete ripening. When, however, an attack is once made, 

 the malady spreads so rapidly as to occasion serious loss before 

 the fruit can be gathered. 



The disease shows itself upon the tomato as sunken, discol- 

 ored spots, each with a dark center, becoming black. These 

 spots increase in size, or by confluence cover a large portion of 

 the decaying fruit. Over this area the fruit is black and 

 shrunken, flattened or depressed, surrounded by a shrunken, cor- 

 rugated, discolored skin ; the dark centers due to the gregarious 

 acervuli with their dark setae. 



The disease is easily and quickly produced by introducing the 

 spores within a puncture made by a sterilized needle, but no re- 

 sults have yet come from repeated attempts to produce the 

 disease by sowing the spores upon the uninjured surface of either 

 ripe or green tomatoes. The fungus causing the trouble is a 

 species of Colletotrichum. It is clearly distinct from C. nigrum 

 E. & Hal., found by Dr. B. D. Halsted on cultivated peppers, 

 which, however, it somewhat resembles. Attempts to grow the 

 tomato fungus on peppers, even by introducing the spores of the 

 latter beneath the skin, were unsuccessful. 



The following botanical description of the fungus is ap- 

 pended : 



