22 
considered that it is necessary to diagnose the disease and deter¬ 
mine the cause before remedial or preventive measures can be 
rationally applied, it will be seen that this is really the first step 
to be taken. 
The fungus producing Anthracnose or “Black Spot” is a new 
species of Phoma , which I have named Phoma citricarpa. The 
spore-cases are of small size, aud the spores are very minute. 
In Florida a leaf-spot lias been found on both sweet and wild 
orange trees, which has also been named Anthracnose, but it is 
due to quite a different fungus, known as Colletotrichum adustum, 
Ellis. There is also a black disease of the orauge known in 
Italy as “ La Nebbia,” and with which this one has been con¬ 
founded, but it is caused by an entirely different fungus ( Pleospora 
hesperidearum , Catt), the spots being covered by a black powder. 
A careful examination of the fungus settles its identity at once. 
Treatment .—This disease may appear by itself or along with 
other diseases, such as the so-called 44 Melanose,” and the same 
treatment may be applied to both. Not having had an oppor¬ 
tunity of carrying out experiments on the disease further than 
to show that the spores are prevented from germinating by dilute 
Bordeaux mixture, I can only suggest, and not recommend— 
1. The skins of diseased fruits should be burnt in order to 
prevent the spores reaching fresh growing fruits. 
2. The cases carrying the diseased fruit should be disinfected. 
This may be done by dipping the cases for a few 
minutes in boiling water. 
3. Drainage should be particularly attended to, since citrus 
trees are very sensitive to water lodging at the root. 
4. Spray with Bordeaux mixture as soon as the fruit sets, 
as recommended for the 44 False Melanose.” This may 
bo continued every four weeks up to about a month 
before the ripening of the fruit. 
5. Also spray with Bordeaux mixture after the .crop is 
gathered, to destroy the inevitable spores lodging about 
the tree. 
G. Sulphate of Iron, at the rate of about half-a-pound, may 
be applied to the feeding roots of each tree, either by 
sprinkling and watering, or by dissolving in water, at 
the rate of 1 oz. to 3 gallons. Every reasonable pre¬ 
caution should be taken to prevent the introduction of 
the disease into Victoria. 
References. 
Benson (A. II .)— c( Black Spot of the Orange.” Ag. Gaz., 
N.S.W., Vol. VI., l J t. 4, p. 249 (1895). 
Cobb (N. A.)— 44 Black Spot of the Orange.” Ag. Gaz., N.S.W., 
Vol. VIII., Pt. 4, p. 229 (1897). 
