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4 Jan., 1902.] QUEENSLAND AGRICULTURAL JOURNAL. 67 
PEACH-TREES DYING, &c. 
Cintra Jack.—Black Jack P.C., Charters Towers— 
Question 1.— W hat causes peach-trees to gradually close their leaves, com- 
mencing near the main stem to the tips of the branches, when the 
tree nearly always dies? I could see no sign of white ants. 
Mr. H. Tryon, Entomologist, furnishes to questions 1 and 3 as 
follows :— 
Answer 1.—The shedding of the foliage of the peach is occasioned during 
spring by the curl or blister disease of the leaf, itself caused by 
the parasitic fungus, Hxosacus deformans; in autumn by leaf rust 
(Puccinia pruni) ; and at any time during the summer may result 
from the presence of root-frequenting gall worms, root-tunnelling 
weevil-larvee (Leptops sp., &c.), or constitutional disease, the latter 
arising from unsuitable soil conditions, either physical or chemical 
in their nature, and of either transitory or permanent occurrence. 
Question 2.—What causes grape vine cuttings to shoot and then die off ? 
I have lost hundreds in this way. 
Mr. Rainford, Viticulturist to the Department of Agriculture, says :— 
Answer 2.—The causes may be two. One, an unusually dry season 
whereby the young roots draw insufficient moisture to maintain the 
leaves ; and another, their being planted in badly-drained soil, which 
causes sickness in the young plant. The former would be an occa- 
sional mishap, the latter of constant occurrence. For the first, 
water till established ; for the second, plant in another soil. 
Question 3.—Can you tell me how to protect orange and other trees 
from winter frosts. I lost a number this year, killed down to 
the ground. Some shot above the graft, some below, and some not 
at all. This is a dry climate, and I have to water in winter. Is 
that the cause ? 
Answer 3.—Methods adopted in Queensland for protecting orange-trees 
from the prejudicial effects due to frost are as follow :—(1) 
Burning rubbish during the night on which frost is anticipated along 
the boundaries of the orchard ; the heaps being so situated as will 
admit of the smoke as generated passing amongst and over the 
trees. (2) Covering trees with bush hay or placing this or fine brush 
ona canopy or platform erected over them. (8) Planting lofty 
shade trees along the eastern border, or, in establishing the orangery, 
reserving a belt of high timber in this situation. (4) Tile-draining 
the land. Methods Nos. 2 and 3 have reference to the fact that 
in Queensland it is not generally the absolute cold that injures the 
orange-tree, but the too sudden influence of ardent sunshine imme- 
diately after it has been subjected to a comparatively low nocturnal 
temperature. ‘‘ Freezes,” such asare experienced in other parts of 
the world—did they occur—need be counteracted by still different 
methods from those specified. Ivrigating the soil during the winter 
months in a dry climate in providing increased evaporation tends to 
lower the surface temperature, and so also that of the air above it. 
On the other hand, the vapour passing off tends to render the air 
Jess pervious than otherwise to the passage of radiant heat, and so 
impedes this decrement of temperature. There are additional 
factors, however, that modify the influence of irrigation on 
temperature in a dry climate. These vary in their operation with 
the locality and concern, lie and contour of land, nature of soil, &c, 
m1) 
