September, 1955 ForsBerG: FUSARIUM 
hard, rough, and usually somewhat scaly 
after the corms are dry. The affected area 
is sunken, and there is a sharp line of de- 
marcation between diseased and_ healthy 
tissues. 
While the majority of diseased corms 
in any given lot usually have symptoms 
characteristic of only one of the disease 
forms, it is not uncommon to find corms 
that have symptoms of two of the disease 
forms Or symptoms intermediate between 
them, fig. +. Bald (1953) stated, “In any 
large collection of gladiolus varieties in- 
fected with Fusarium diseases it has not 
been found possible to maintain on a symp- 
tomological basis the division between Fu- 
sarium basal rot and Fusarium yellows. 
On different varieties a gradation was 
found between the 2 symptom types.” 
451 
DIsEASE OF GLADIOLUS 
ETIOLOGY 
The etiology of the Fusarium disease of 
gladiolus is quite typical for that of plant 
diseases caused by fungi of the genus Fu- 
sarium. ‘The occurrence of the disease in 
more than one form and the great varia- 
bility commonly found in species of Fu- 
sarium have contributed to the confusion 
regarding the cause of this disease. 
Previous Accounts 
A report by Massey (1922) was the 
first published account of a gladiolus dis- 
ease in which a fungus of the genus Fw- 
sarium was established as the cause. A 
more extensive description of this disease 
and its causal agent was later published by 
Fig. 3—Corms of three gladiolus varieties affected with the basal dry rot form of the 
Fusarium disease: top row, variety Gold Eagle; middle row, Lake Placid; bottom row, Spot- 
light. The two sectioned Spotlight corms show the extreme thinness of the rotted tissue. 
