l86 MAINE AGRICUIvTURAL EXPERIMENT STATION. I909. 



Coryneum foliicolum Kckl. 



This fungus occurs so commonly on leaf-spot of the apple 

 as to suggest the possibility that, in some cases, it may be the 

 cause of that disease. This species seems to be more or less 

 widely distributed as it is reported as common in West Virginia 

 by Hartley (3) and in New Hampshire by Lycwis (4). Hartley 

 suggests that it is probable that the fungus which has been 

 reported from several states as Hendersonia mali Thiim, is 

 really Coryneum foliicolum Fckl. and, if this be true, the distri- 

 bution of the fungus would be considerably widened. It would 

 be very easy to confuse the two species unless sections were 

 prepared to show how the spores are borne as the spores are 

 very similar. On a single leaf-spot several of the fruiting pus- 

 tules of the fungus may be found„ Spores are produced from 

 these pustules in large numbers and become piled up in black 

 carbonaceous masses which somewhat resemble pycnidia. 

 When sections of these pustules are examined, however, it is 

 found that the fungus belongs to the Melanconiales as shown 

 by Figures 28 and 29. 



Hartley (3) has made some study of Coryneum foliicolum 

 in connection with a more thorough study of Coniothyrium 

 pirifia (Sacc.) Sheldon. He grew the fungus in pure culture 

 and made some inoculations but came to the conclusion that 

 Coryneum is less actively parasitic than Coniothyrium. 



On account of the frequent occurrence of this fungus on 

 leaf-spot in Maine orchards in 1908, the writer felt that further 

 investigation was desirable. This seemed more necessary when 

 it was found that spores similar to those found on the leaf- 

 spots occurred very frequently in cankers on apple branches. 

 Cultures from these spores showed that the fungus in the 

 cankers and the one on the leaf-spots were identical. 



INOCUEATION EXPERIMENTS. 



Experiments were carried on to determine the extent of para- 

 sitism of the fungus on leaves, wood, and fruit of the apple. 

 Material from pure cultures was used in making all inocula- 

 tions. The abundant production of spores in culture, and the 

 fact that the spores germinate in a few hours in water should 

 make this fungus a favorable one to use in infection experi- 

 ments. 



