15 
be made just as the leaves start in spring. At least three other spray- 
ings should be made at equal intervals between the time of the first 
treatment and the time for budding. Ten or twelve days after budding 
the last spraying should be made, making five in all. For blocks of 
50,000 to 100,000 seedlings the total cost of the treatment, as indicated, 
need not exceed § cents per thousand. In smaller blocks the average 
cost per thousand trees will be somewhat greater, as it requires prac- 
tically as much time to prepare to spray 25,000 trees as it does 50,000. 
The knapsack pump is well adapted to this work and is extensively 
used by nurserymen. Larger machines designed to be drawn by a 
horse have been described by us in Circular No. 10 of the Division of 
Vegetable Pathology. 
TREATMENT OF PEAR SCAB, CRACKING, AND LEAF-BLIGHT. 
These diseases, caused by two different species of fungi, are now suc- 
cessfully 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 alldesirable. The first spray- 
ing 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 standard trees 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 ot 
treating with the ammoniacal solution will be considerably less, prob- 
ably not exceeding 10 cents for standard and 8 cents for dwarf trees. 
In the nursery pear seedlings can be treated six times with the Bor- 
deaux mixture for 50 cents per thousand. 
TREATMENT OF LEAF-BLIGHT OF THE CHERRY, PLUM, AND QUINCE. 
This disease, which seriously damages the trees both in the nursery 
and orchard, may be readily 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, crack- 
ing, and leaf-blight are applicable here. 
TREATMENT OF BLACK-ROT OF THE GRAPE. 
, Method A.—After pruning the vineyard and putting the ground in 
tLorough order spray the vines first, as the buds begin to swell, with 
T>rdeanx mixture. When the leaves are one-third grown make a see 
