a 
39 
wash—the former preferable—the potash fertilizers, muriate and 
kainit, and bisulphid of carbon. The simple remedies are applica- 
tions of strong soap or tobacco washes to the soil about the crown; 
or soot, ashes, or tobacco dust buried about the roots; also similarly 
employed are lime and gas lime. Submersion, wherever the practice 
of irrigation or the natural conditions make it feasible, has proved of 
the greatest service against the phylloxera. 
HOT WATER. 
As a means of destroying root-aphides, and particularly the woolly 
aphis of the apple, the most generally recommended measure hitherto 
is the use of hot water, and this, awhile being both simple and inex- 
pensive, is thoroughly effective, as has been demonstrated by practical 
experience. Water at nearly the boiling point may be applied about 
the base of young trees without the slightest danger of injury to the 
trees, and should be used in sufficient quantity to wet the soil thor- 
oughly to a depth of several inches, as the aphides may penetrate 
nearly a foot below the surface. To facilitate the wetting of the 
roots and the extermination of the aphides, as much of the surface 
soil as possible should be first removed. 
By a hot-water bath slightly infested stock can be easily freed of 
the aphides at the time of its removal from the nursery rows. The 
soil should be dislodged and the roots pruned, and in batches of a 
dozen or so the roots and lower portion of the trunks should be im- 
mersed for a few seconds in water kept at a temperature of 130° to 
150° F. A strong soap solution similarly heated or a fifteen times 
diluted kerosene emulsion will give somewhat greater penetration and 
be more effective, although the water alone at the temperature named 
should destroy the aphides. 
Badly infested nursery stock should be destroyed, since it would be 
worth little even with the aphides removed. - 
TOBACCO DUST. 
Some very successful experiments conducted by Prof. J. M. Sted- 
man demonstrated the very satisfactory protective, as well as reme- 
dial value of finely ground tobacco dust against the woolly aphis. 
The desirability of excluding the aphis altogether from nursery stock 
is at once apparent, and this Professor Stedman shows to be possible 
by placing tobacco dust freely in the trenches in which the seedlings 
or grafts are planted and in the orchard excavations for young trees. 
Nursery stock may be continuously protected by laying each spring a 
line of the dust in a small furrow on either side of the row and as 
close as possible to the tree, and covering loosely with earth. For 
large trees, both for protection and the destruction of existing 
aphides, from 2 to 5 pounds of the dust should be distributed from 
the base outward to a distance of 2 feet, first removing the surface 
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