382 MINNESOTA STATE HORTICULTURAL SOCIETY. 
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 6 to 8 cents per tree. 
APPLE POWDERY MILDEW. 
Tt is only in nurseries that this disease is destructive. Seedlings are 
especially subject to the mildew, the leaves being attacked as soon as they 
appear. Asaresuit the trees make very little growth, are bark bound, 
and consequently unfit for budding. The ammoniacal solution has proved 
the cheapest and most effective remedy for this disease, and five sprayings 
seem to be required. The first application should be made just as the 
leaves start in spring. At least three other sprayings should be made at 
equal intervals between the time of the first treament 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 8 cents per 
thousand. In smaller blocks the average cost per thousand trees will be 
somewhat greater, as it requires practically 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. i0 of the Division of Vegetable Pathology. 
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 di- 
rections laid down for the treatment of pear scab, cracking, and leaf- 
blight are applicable here. 
TREATMENT OF BLACK-ROT OF THE GRAPE. 
Method A.—After “pruning the vineyard and. putting the ground in 
thorough order, spray the vines first, as the buds begin to swell,with Bor- 
deaux mixture. When the leaves are one-third grown make a second ap- 
plication of the same fungicide, following with a third when the vines 
are in full bloom. After this, applications should be continued at inter- 
vals of ten or twelve days until the first signs of ripening are noticed. 
This will usually be three weeks or a month before the grapes are ready 
to pick. In no case should the treatments be continued up to the time of 
harvest, as this is entirely unnecessary; moreover, it is sure to render the 
fruit unsightly. It is important to bear in mind that, in case of dry 
weather, the sprayings should cease. 
Method L.—¥Follow the direction laid down under method A, with 
the exception that the ammoniacal solution be used instead of Bordeaux 
mixture. ire 
Method C.—For the first three sprayings use the Bordeaux mixture, then 
substitute the ammoniacal solution for the rest of the season. 
