336 
(5) These results indicate that for Virginia the first treatment should 
be made between May 15 and June 1 or even on the latter date, and for 
regions farther north at correspondingly later dates$ or to state the 
proposition in general terms, the first spraying should be given from 
four to six weeks after the trees blossom, and the second treatment 
should be made one month later. 
The question naturally arises whether these results can be relied upon 
without repetition during a series of years. Of course one would feel 
much safer if they were repeated at least one season. Pear leaf-blight, 
however, is well known to be a very regular disease, both as to preva¬ 
lence and severity, and exceptionally uniform during different seasons. 
This constant character of the disease makes the conclusions much 
safer than they would be with almost any other fungous disease. 
It may be well to state that these conclusions do not apply to nursery 
stock or to trees which for auy reason make a new growth late in the 
season. In another part of the orchard in question a block of trees 
which had been pruned back severely to renew the whole top was 
sprayed four times, the last treatment being on June 30. These trees 
made 3 to 5 feet of growth and at the close of the season the last 0 or 
8 inches of the more vigorous shoots, which had doubtless grown after 
the last treatment, were either defoliated or spotted with leaf-blight. 
From this it is evident that trees putting out new growth require addi¬ 
tional sprayings to protect the new leaves as they appear. 
TREATMENT OF THE ORCHARD AS A WHOLE. 
The orchard as a whole was sprayed with the same strength of Bor¬ 
deaux mixture as the experimental plats, i. e., the 50-gallon formula. 
In making the mixture a method of preparing and using a stock solu¬ 
tion of copper sulphate was devised, which saved the time required to 
weigh out and dissolve the copper salt for each separate quantity of 
the mixture. At the suggestion of the writer the plan has since been 
tried in New Jersey and New York, and has proved to be a great sav¬ 
ing of time where a large amount of spraying is to be done. A barrel 
holding 50 gallons should be selected and 100 pounds of copper sul¬ 
phate (large crystals can be used) suspended in a basket or a piece of 
coarse sacking in the upper part of it. The barrel is then filled with 
water. In the course of a day or two all the copper will be dissolved. 
The basket is then removed and more water is added until the barrel 
is again full. This second addition of water is necessary to fill the 
space which was occupied by the copper before it was dissolved. Each 
gallon ot this solution will contain U pounds of the copper salt. If the 
copper salt is placed in the bottom of the barrel, it will be dissolved 
only with difficulty. It should be noted that considerably less than 50 
gallons of water is added, owing to the fact that the copper occupies 
some ot the space, but that the final solution of copper sulphate and 
