r 



A DISEASE OF CULTIVATED AGAVES DUE TO COLLETO- 



TRICHUM. 



BY GEORGE GRANT HEDGCOCK. 



A number of small agave plants 



Aga 



UtahensiS) secured from its natural home, were potted dur- 

 ing the spring of 1904, and during the earlier part of the 

 summer. These were placed along with a large number of 

 agaves of various species in the soil on a western exposure 



G 



den. 



many plants were found dy 



a disease which first attacked the older leaves. A micro- 

 scopical examination of a number of the diseased leaves re- 

 vealed the constant presence of a fungus, apparently of the 



© 



Gloeospo 



that in all the older acervuli of the fungus the character- 

 istic setae of G olletotrichum were present, thus placing it 



under this genus. 



i 



from 



moist chamber were made by wounding the leaves of 



mas 



the spores in the wounds. Control plants were similarly 

 wounded, but not infected. The inoculated plants in 

 about two weeks became diseased in the same manner as 

 those from which the spores were taken, and in a short 

 time after produced characteristic acervuli of Cottetolri- 



chum. 



Cultures were made from conidia taken from masses exud- 

 ing from acervuli on the leaves of plants under bell jars, 



o 



most 



Colonies were secured which grew to a diameter of one to 



two inche 



s 



A dark m 



numerous knotted 



mas 



(153) 



