846 REPORT OF THE COMMISSIONER OF AGRICULTURE. = 
_ where they can do harm. A practical treatment has been discovered 
_what season it is best to make the applications, and the strength to’ 
and carbonate of copper solution may be kept ina bottle and diluted 
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wholly prevented in very dilute solutions of sulphate of copper, and yi 
our chief dependence in combating this disease appears to rest upon 
this fact—the possibility of preventing the germination of the spores 
by which we may prevent the germination of the spores of thedowny 
mildew of the grape-vine by applying various solutions of sulphate — 
_ of copper to the surfaces of the leaves upon which the spores of the 
fungus fall. itis doubtless equally practical to accomplish by a simi- _ 
lar treatment, a like result in the case of the Fusicladiwm of theapple. 
Experiments already made with the sulphate of copper solutions indi- 
cate that they will, when properly applied, at once check the ‘‘scab.” 
Further and more systematically conducted experiments are required 
in order to determine fully what preparation is most efficacious, at 
which the solutions must be limited. Where eau celeste, prepared 
according to the original formula, has been tried it has severely : 
burned and injured the foliage. This preparation may be rendered 
less caustic by the addition of ordinary carbonate of soda, or by 
being prepared as directed on page 331. . 
Another and more simple modification of the eau celeste is pre- « 
pared by dissolving in 1 quart of liquid ammonia 4 to 6 ounces of car- 
bonate of copper, then dilute with water to 25 gallons. The ammonia i 
when required for use at the rate of about 1 ounce of the solution to 
the gallon of water. Those who have used this preparation on the 
grape-vine say it is perfectly harmless to the foliage and is as effi- 
cacious against mildew as eau celeste. Itis simple and easily pre- 
pared and is very strongly adherent to the foliage. ; 
Simple solutions of sulphate of copper ought not to be employed 
during the growing season as their use is almost certain to result in 
injury to the foliage. The Bordeaux mixture (see page 328) may be 
used at any time without fear of injury. 
Using one or the other of the above preparations, the following _ 
course of treatment is suggested : 
(1) In early spring, before the buds have commenced to expand, 
spray the trees thoroughly with a solution of sulphate of iron, using — 
4 pounds of the iron sulphate to 4 gallons of water. 
(2) As soon as the fruit has set, apply the Bordeaux mixture or 
one of the modified preparations of eau celeste. 
(8) If the weather should be such as to favor the development of y 
the “‘scab” fungus, a third application should be made two or three 
weeks after the second, using the same materials. . 
In addition to the effect that these applications may have on the 
development of the fungus, they will doubtless serve to keep off 
many insect pests. ) 
In storing the fruit for winter, especial care should be takento __ 
separate all the apples showing any signs of the scab from those — 
which are smooth and healthy, and they should all be kept in rooms 
or cellars free from moisttire. 
The Nixon’s pumps, or Field’s force-pump, are good appliances for - 
spraying the simple solutions and eau celeste, and, substituting the 
nozzles furnished with these for the Vermorel nozzle, they may be . 
employed to apply the Bordeaux mixture. In employing solutions 
containing sulphate of copper it is essential that the pumps be made 
of copper and the valves should be made of rubber; if the latter are 
of leather they ought to be oiled frequently during the applications, 
