269 
XLIT.—ON THE OCCURRENCE OF A SPECIES OF 
FUSARIUM IN UGANDA. 
W. SMALL. 
Tn a previous communication to the Kew Bulletin,* the present 
writer described from Uganda a wilt of carnations, Delphinium, 
Nigella and Cosmos which was shown to be due to a species of 
Fusarium. The same Fusarium has been encountered since 
on other plants, and it is thought that an account of its occurrence 
may be of some interest. The new host plants include seedlings 
of the cashew nut (Anacardium occidentale, L.), the silky oak 
(Grevillea robusta, A. Cunn.), the rose apple (Eugenia jambos, L.), 
and the loquat (Hriobotrya japonica, Lindl.). The attack of th 
Fusarium on the first of these takes the form of a severe wilt 
disease which is new, so far as the writer is aware, and which is 
described in some detail in the following pages. The occurrence 
of the Fusarium on the other three hosts is not of the same deadly 
nature as on the first, but is nevertheless worthy of record and 
discussion. The fungus has been found also on carnations and 
Antirrhinum associated with Heterodera radicicola, Greef. The 
facts recorded in this paper extend the host range of this fungus 
which is now provisionally labelled Fusarium udum, Butl. There 
are doubtless numerous unreported cases of the deaths of garden 
and other plants, and it is probable that so vigorous a fungus 
and one so difficult to eradicate when established in the soil, 
is pathogenic to many plants. It has been recorded on only 
one plant of economic importance in Uganda, the pigeon-pea 
(Cajanus indicus, Spreng.) and then, not as an original, but as 
an induced infection, the result of an experiment which is men- 
tioned later. Evidence obtained from soil cultures points to its 
being able to subsist saprophytically and tide over non-parasitic 
periods of its life on organic debris in the soil, while it would 
appear to gain an entrance to the tissues of its host through the 
smaller roots after the typical manner of the soil-dwelling, semi- 
saprophytic fungi that cause wilt disease. Various species of 
Fusarium behave in this manner. That the species under 
discussion should be included among them is supported by the 
results of the inoculation experiments carried out. 
Symproms oF THE Witt Disease oF CasHEW Nut. 
The writer’s attention was drawn to the cashew nut wilt 
in April 1921 by the officer in charge of the Government Planta- 
tion, Kampala, who pointed out that a large number of cashew 
nut seedlings was dying off in the nursery. A cursory glance at 
a bed of seedlings was sufficient to show that the percentage of 
affected plants was very high, and subsequent observations in 
several groups of plants showed as much as 100 per cent. There 
seemed to be no case of recovery from an attack of the fungus. 
* Kew Bulletin, 1920, p. 321. 
