Pomona College Journal op Economic Botany. 333 



placed in a moist chamber developed from their ends a profuse white 

 mycelium bearing Fusarium macroconidia. Another plant of the same 

 variety was used for control; it was given the same treatment except for 

 the slit and paraffin seal. It did not become diseased. 



]\Iarch 7th — Two Enchantress carnation plants, fourteen weeks of age, 

 were inoculated with pure cultures of strain (R) by the "slit" method. 

 The pots containing these plants were placed in larger pots and covered 

 with window glass, thus providing a more humid atmosphere for the devel- 

 opment of the fungus. Within four weeks one of the plants became seri- 

 ously diseased, an abundance of flesh-colored clusters of spores developed 

 on the outside of the stem and mycelium was found in the tissues. The 

 other plant became infested with various organisms, and no definite result 

 was obtained. Control plants kept under the same conditions did not 

 become diseased. 



March 3rd — A one-year-old Enchantress carnation plant was inoculated 

 with a pure culture of the (R) strain by the "slit" method and kept under 

 a bell jar. On April 2nd the lower branches of the plant became wilted 

 and pale yellow in appearance. On April 5th tlie entire foliage of the 

 plant presented a wilted yellowish appearance, very characteristic of the 

 stem-rot or wilt disease. Its stem, for a distance of one inch above and 

 below the point of infection, was thoroughly decomposed. An examination 

 of a cross-section of the diseased portion showed the presence of abundant 

 mycelium and for the first time Fusarium macroconidia were found borne 

 in the living cells. This stem also contained a small brown streak of broken- 

 down parenchyma cells, extending above the zone containing mycelium. The 

 continued presence of such brown areas without mycelium in both arti- 

 ficially and naturally diseased plants seems to indicate that the plant tissue 

 is destroyed in some way in advance of the mycelium. Segments of the 

 diseased stem of this plant, placed in a moist chamber, developed a profuse 

 white mycelium at their ends also. A plant of the same variety and receiv- 

 ing exactly the same treatment, except for the inoculation, did not become 

 diseased. 



April 3rd — Two Prosperity carnation plants, about twelve weeks old, 

 were inoculated with strains (IV) and (VII), respectively, by putting an 

 abundance of the pure culture material into the soil and in contact with 

 the stems of the plants. These plants were kept under bell jars and control 

 plants were kept under similar conditions. These plants gave no indications 

 of disease on May 1st. 



April 3rd — Three potato plants, which were just beginning to form 

 potatoes, were inoculated with strains (IV), (VII) and (H), respectively, 

 by the "silt and paraffin" method. Each pot contained two plants, one 

 being used for a control. These plants were kept under bell jars. These 

 inoculations were not successful. 



