84 
PLANT DISEASES. 
four sprayings should be made, the first just as the flowers are 
opening, the second twelve or fourteen days later, and the third 
and fourth at similar intervals. In case the season is wet one or 
two additional treatments will undoubtedly pay. For trees 15 to 18 
feet high the cost of four sprayings with either of the fungicides 
mentioned need not exceed 20 cents per tree. When the work is 
done on a large scale 16 to 18 cents per tree will cover the cost of 
four treatments. Two additional treatments will add to the cost 
from six to eight cents per tree. 
Treatment of Pear Scab , Cracking , and Leaf Blight. 
These diseases, caused by two different species of fungi, are now 
successfully combated by one line of treatment. In most sections 
all three diseases are found associated. Bordeaux mixture has 
given the best results in this work, although ammoniacal solution 
has proved almost as effective. The only objection to the latter is 
that it sometimes gives the fruit a rusty appearance, which is not 
at all desirable. The first spraying for these diseases should be 
made when the trees are in flower. In ten or twelve days a second 
treatment should be made, followed by a third and fourth at the 
expiration of two and four weeks respectively. In the nursery pear 
leaf blight is often exceedingly troublesome. It may be almost 
entirely prevented by spraying five or six times with the Bordeaux 
mixture, making the first application when the leaves are about 
one-third grown, and the others at intervals of ten or twelve days 
throughout the season . 
The cost of treating full-grown standingtrees with the Bordeaux 
mixture, as indicated, will average from 12 to 14 cents per tree. 
For dwarf trees the cost will range from 8 to 12 cents each. The 
cost of treating with the ammoniacal solution will be considerably 
less, probably not exceeding 10 cents for standard and eight 
cents for dwarf trees. In the nursery pear seedlings can be treated 
six times with the Bordeaux mixture for 50 cents per thousand. 
Treatment of Leaf Blight of the Cherry , Plum , and Quince. 
The disease, which seriously damages the trees both in the 
nursery and orchard, may be held in check by the proper use of 
either Bordeaux mixture or the ammoniacal solution. In the 
orchard and nursery the directions laid down for the treatment of 
pear scab, cracking, and leaf blight are applicable here. 
Does it Pay to Spray ? 
This question is in large part answered by the facts already 
given. No work that did not carry merit with it could have such 
a phenomenal growth. To give a more direct answer, however, it 
may be stated that last season two hundred and fifty grape growers 
in different parts of the country made a series of observations with 
a view of obtaining some definite information as to the value in 
