226 
hensis. A vain search for bark diseases caused by Phytophthora 
Faberi was conducted throughout the year, but up to the end 
of 1914 when Brooks left for England there was uo cause for 
uneasiness. 
Investigations on the disease caused by Ustulina zonata were 
carried forward, and in 1916 serious attacks by this fungus were 
noticed. About the beginning of 1916, Belgrave (2), who was 
appointed Assistant Mycologist just before Brooks left, commenced 
investigations on a wet rot of Hevea roots, which appeared quite 
distinct from the dry root-rot caused b . zonata. A pre- 
liminary statement of his work has been given (2) but the full 
account has not yet been published. ~ 
The following cases of serious attacks of root disease may 
be quoted :—(A) The Government plantation behind the oftices of 
the Department of Agriculture at Kuala Lumpur carries about 
seven acres of 15-year old trees. A fair number of trees attacked 
by Ustulina zonata were known, but only one small group of 
six trees was known to be affected with wet root-rot. To obtain 
specimens and observe the disease below ground, this group 
together with the neighbouring trees, was opened up. It was 
obvious from the commencement that the subterranean spread 
roots of two hundred and twelve trees were exposed and 40 per 
cent. showed diseased roots, largely caused by the fungus pro- 
ducing wet root-rot. The matter was so serious that at the 
request of the Advisory Committee to the Department of Agri- 
culture, all the trees in the seven acres of old rubber had their 
roots exposed, and of the 700 trees in the whole area 20 per cent. 
showed diseased roots. 
(B) Another illuminating case was noted a few months ago. 
A wind storm locally known as a ‘‘ Sumatra’”’ swept over a portion 
of one estate and numbers of 17-year old trees were blown over. 
Only three of these prostrate trees showed healthy roots, and 
these were without tap roots. A few of the fallen trees had pre- 
viously been treated for U. zonata, but the great majority, which 
were not suspected to be suffering from root diseases, were found 
to have this fungus attacking the roots. A few cases of branch 
infections with U. zonata, and a few trees with wet root-rot were 
eep them under control. 
The necessity for active sanitation measures in Malaya is 
apparent to all who have studied the accounts of these root-rots, 
ut no justification existed for assuming that diseases of rubber 
need prove an active factor in inhibiting the development of 
Malayan plantations. In Malaya, diseases on the plantations 
have been effectively combated by growing more trees per acre 
than are absolutely necessary, at the same time avoiding over- 
