308 QUEENSLAND AGRICULTURAL JOURNAL. [1 Ocr., 1898. 
to nearly one-fourth of an inch across; and in several instances have coalesced 
or united, so that stiil larger areas of discoloured tissue are produced. Leaves 
more badly affected still are turning brown from the tip and edges inwards, but 
the majority are already dead and shrivelled up. The calycine leaves of such 
stunted fruit as is still green are similarly diseased, but there is, however, little 
fruit that has not already wilted and become brown, and is now hanging from 
withered and shrunken foot-stalks. Most of the roots, too, are already dead, 
though a few fresh ones seem to have been recently put forth.” 
It usually happens, however, that the symptoms manifested by strawberry 
plants affected by Leaf Blight are less pronounced, and that the disease is less 
quickly fatal, but its existence will always be indicated in the presence upon 
the foliage of purple, or purple-grey ceutred, spots in however small number 
these may be manifested. 
EFFECT OF DISEASE. 
Unless exceptional circumstances exist or supervene to naturally check 
the progress of the disease, it will always seriously injure the plant in connec- 
tion with which it occurs. This injury may not be at once manifested, but the 
affected plants will gradually become weakened, and, if they produce fruit at 
all this will be very uneven in size and irregularly ripened. ‘They will also 
‘become stunted, owing to their inability to assimilate food material in conse- 
quence of their foliage being infected. 
A New South Wales correspondent of the Department of Agriculture of 
that colony writes as follows on this subject:—I forward herewith a 
specimen of strawberry plant, showing the way the plants wither in their 
efforts to ripen their fruit. When planted they grow vigorously, and throw 
out a promising lot of bloom; but, after re-opening one or, possibly, two 
fruits, the remainder of the plant withers as though scorched by fire. " After 
a short rest the plants again throw out fresh leaves, and bloom as before, with 
the same disappointing results. This process is repeated throughout the 
season.’ This testimony is quoted by Dr. N. A. Cobb [(21), p. 61]. 
A. H. Benson, formerly an officer of the Department of Agriculture of 
the above-mentioned colony, has also informed the writer as the outcome of 
his own personal observations, that whereas formerly the Chatswood, Ryde, 
and Parramatta divisions, of the county of Cumberland, constituted a large and 
important strawberry-growing area in that country, the cultivations devoted to 
this plant in these districts have now, for the most part, been abandoned in 
consequence of the occurrence of Leaf Blight. F. L. Jensen [ (29), p. 480], 
in an article on the strawberry, moreover, alludes to the occurrence of Leaf 
Blight in New South Wales, characterising it as ‘a really serious strawberry 
disease.” 
CONDITIONS FAVOURING DISEASE. 
1. Environment.—It has been held, by some of the best authorities on 
' plant pathology, that heavy clay soils, as distinguished from lighter sandy ones, 
are especially conducive to the presence of the disease. Amongst these may 
be mentioned Sorauer, and Briosi, and Cavara [(8), No. 14]. In fact, the first- 
mentioned sayant goes so far as to state his opinion that the general spreading 
of the disease can best be counteracted by setting the plants in fertile, loose, 
sandy soils, in open sun-exposed situations [(5), p- 3683]. This prejudicial 
influence, exerted by soils of the character mentioned, has not been universally 
remarked. Observations in Queensland, however, point to the conclusion that 
strawberry plants grown in shallow soils, reposing: on ill-drained stiff subsoils, 
are especially subject to the presence of Leaf Blight. Sudden changes in the 
prevalent character of the weather arealso conducive to the increased virulence 
of the disease; such asadry “spell” following, with little interval, a wet 
season, as also the opposite conditions. An unusually heavy crop may also be 
followed by a bad attack; and, generally, any condition that tends to weaken 
the plant, or to militate against its successful growth, favours the development 
of Leaf Blight. 
