554 
In the second instance, the ground should be deeply ploughed, 
thorouthly drained, and liberally limed and manured, so as to 
eicyira se the growth of the roots in healthy surroundings. (See 
Pear Blizht.) 
In every case examine the subsoil. In many cases the ground 
is unsuited for the healthy growth of fruit trees and is not such as 
will carry a commercial orchard. <A hard pan of impervious clay 
or of cement ground would prevent the roots dipping down in search 
of nourishment and would become water logged and stop root 
development. In other cases a layer of coarse sand or gravel 
underneath is interposed between the dry surface and the moister 
subsoil, and prevents the rise of the moisture from below ; in other 
cases again, the rise of the bottom water impregnated with saline 
matters check root growth and starves the tree. 
Water Core.—Easily known by the watery or waxy appear- 
ance of either the whole or part of an apple. The apple is quite 
sound to outward appearance. More prevalent in moist seasons, 
especially in early sorts. Wiaiter varieties are comparatively free 
from it. Stone Pippin and Five Crown Pippin are somewhat 
subject to it, also seen in Rokewood. 
It is also noticed in dry districts, but to a lesser degree. The 
glassy palites are due to the exclusion of air amongst the cells of 
fruit and its replacement by sap. If the soil and the subsoil are 
guarded against extremes of dry or wet by drainage, irrigation or 
cultivation, the trouble is readily kept down. 
PowpERy MILDEW oF THE APPLE, PEAR, AND QUINCE (Podo- 
sphera Kunzet, Lev.), sometimes called ‘“‘fire blight.” Very de- 
structive to nursery stock. Attacks the apple, peach, quince, 
cherry, and other plants belonging to the Rosacew. It attacks 
mostly the young leaves, spreading over both surfaces, and showing 
like white felt. Spray with Bordeaux mixture or with Iron sul- 
phide spray (V. No. 15). In summer time, sulphur the trees. 
Cleopatra and Stone Pippin appear to be especially liable. 
Pear Buiaut, on Fire Buicut (see Twig Blight, p. 552).—A 
bacterial disease which attacks apples, pears, quinces, loquats, and 
other trees. It works in the tissues between the bark and the 
growing wood, only during the growing season. 
Some varieties of pears, like the Duchess and Kieffer’s Hybrid, 
resist the disease better than others, such as Bartlett and Clapp’s 
Favourite. 
The blight microbe Bacillus amylovorus, is greatly influenced 
by climatic conditions ; warm and moist weather, with frequent 
showers, favouring it. These conditions are prevalent in the month 
or two following bossoming time. Dry, cool, and senny weather 
hinders it, while very dry weather checks it ; and it remains dor- 
mant during the winter. The line of demarkation between healthy 
and diseased wood is then often quite marked. 
