studies of disease producing species of fusarium. 243 



Cucumber Inocueatioxs. 



Species of Fusarium have been isolated from decaying cucum- 

 bers a number of times at this laboratory. In order to deter- 

 mine the extent to which these species and others would cause 

 decay, cucumbers were inoculated with .material of the forms 

 isolated from cucumber, F VII, F XIX, F XX, squash, F 

 XXIII, China aster, F XIV, sweet corn, F VI, apple F XII, 

 and F II. All of these fungi caused a rapid decay. The 

 appearance of 2 of the inoculated cucumbers is shown in Figs. 

 117 and 118. 



IXOCUEATION OF CaRNATION BuDS. 



Owing to the similarity in cultural characteristics of the 

 fungus with obovate spores from apple and the carnation bud 

 rot fungus described by Stewart and Heald, it was decided to 

 test the apple fungi on carnation buds in order to determine 

 whether or not they would cause the bud rot. Later, the work 

 was extended to include fungi from a number of other sources, 

 a part of which were typical species of Fusarium. Four varie- 

 ties of carnation were used,- — Enchantress, Windsor, Gomez and 

 Lady Bountiful. All of these, except the Gomez, were suscep- 

 tible to the attack of part of the fungi which were used in mak- 

 ing the inoculations. This variety proved to be very resistant 

 and only a very small per cent of the Gomez buds were injured 

 by any fungus which was tested. The Enchantress was used to 

 a greater extent than either of the other varieties in comparing 

 the amount of injury caused by different fungi. 



All of the inoculations were made in the same wa3^ A small 

 injury was made in the side of the bud with a sterilized needle 

 and a small amount of material from a pure culture was pushed 

 in through the opening. Usually this material consisted of both 

 mycelium and spores. In a few of the earlier experiments, the 

 plants bearing inoculated buds were placed under bell-jars so 

 that the buds were in a moist atmosphere favorable to the 

 growth of the fungus. This procedure was followed for only a 

 very short time as it was felt to be desirable to test the fungi 

 under greenhouse conditions rather than under the abnormal 

 conditions of a moist chamber. 



The detailed account of a number of inoculation experiments 

 ^"ollows. In the first part of the work only a small number of 



