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Other cases of Phorna on roots. —There is a disease of Beet-root 
caused by Phorna, betac (Frank), which attacks the young heart 
leaves and blackens them and extends thence into the roots. The 
mycelium or threads of the fungus spread from the diseased 
parts to the healthy tissues, and the little pustules are developed 
on these spots. 
The Carrot is likewise attacked by a Phoma (P. sanguinolenta 
Rostr .) which causes depressions or canker-like spots on the roots, 
and on the diseased patches numerous dark-grey perithecia occur. 
A Root-rot of the Cauliflower was brought under my notice 
some time ago by Mr. Molineux, of the Agricultural Bureau, 
South Australia, and it was found to be caused by Phoma brassicac 
(Thuem.). The roots often shrivelled and dried up, and in every 
instance the superficial tissue of the diseased roots showed the 
numerous black pustules of the fungus, which in this case never 
extended above ground. 
These instances will show that a similar fungus to that of the 
Root-rot of the Lemon may pass down to the roots from above 
or bo confined entirely to the parts underground. 
Cause of Disease. — The mere occurrence of the fungus on dead 
or dying roots would be no proof of its parasitic nature, but 
having already been found to cause the death of parts above 
ground, it may be assumed to act similarly towards underground 
parts. This fungus has now been found on every portion of the 
tree—root, stem, branch, leaf, and fruit—and it may either pass 
downwards to the roots, or, agreeing with Mr. Williams’ obser¬ 
vations of the disease, beginning at the tips of the roots, oxist in 
the soil and attack the roots there. This would explain many 
cases of so-called Collar-rot which were maintained to have started 
in the roots and travelled upwards to the collar. 
Treatment. —Recognising the fungus as causing the disease, 
there are several precautions which may bo taken to check it and 
prevent its spread. 
1. Drainage should bo attended to, as well as whatever encour¬ 
ages a strong and healthy growth. Deficient drainage is said to 
cause the Root-rot, and this in a sense is true, for stagnant water 
not only favours the spread of the fungus but renders the tree 
weak and liable to attack. 
2. Cut well back in order to start a fresh growth, and see that 
all the portions removed are burnt, as they are probably affected 
with the fungus. 
3. Destroy by burning all fallen leaves from diseased trees, as 
by means of fallen leaves the spores may get into the soil and 
infect the roots. 
4. The addition of 2 lbs. of powdered sulphate of iron and 
an equal quantity of fresh slacked lime to the soil around the 
trunk might prove advantageous. 
