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Plan of the work. —The questions to which answer was sought in the use of these 
materials, and the methods employed to answer them were : 
I. The comparative efficacy of the three compounds named in preventing apple scab. 
Two trees of the Fameuse variety were sprayed with each of the three compounds, 
and their crops compared with those of check trees not sprayed at all. 
II. The efficacy of copper carbonate applied suspended in water, as compared with 
that dissolved in ammonia. 
It was found in 1889 that the ammonia, unless very largely diluted, endangers the 
foliage, and gives the fruit a russety appearance. It also dissolves the arsenic of 
Paris green or London purple when used for the codling moth at the same spraying, 
and this indirectly causes injury to the foliage. To answer the second question, two 
Fameuse trees were sprayed with copper carbonate dissolved in ammonia and two 
others with the same material simply stirred in water, as we apply Paris green. The 
crops of these two pairs of trees were compared with each other, and also with those 
of the check trees. 
III. The value of treatment previous to the opening of the flowers. 
Two Fameuse trees were sprayed once with ammoniacal copper carbonate before 
bloom and three times after, aud their crops compared with those of two other trees 
sprayed four times after bloom. The crops of the four trees were compared with those 
of check trees not sprayed. Also, two trees of the Canada peach variety were 
sprayed with suspended copper carbouate twice before bloom and twice after, and 
their crops compared with those of two others sprayed with the same four times after 
bloom, and also with those of check trees. 
IV. The number of treatments necessary to secure the most beneficial results. 
Two Fameuse trees were sprayed with ammoniacal copper carbonate 2,4,6, and 8 
times respectively, and the crops of the different pairs compared with each other 
and with check trees not sprayed at all. 
The strength at which the fungicides were used .—The copper carbonate was in every 
case of the precipitated form and when applied in the diluted ammoniacal solution 
was used at the rate of an ounce of the salt to 25 gallons of water. One ounce was 
dissolved in a quart of ammonia (strength 22° Baum6) and the solution added to the 
water just before the treatment at the rate named. 
When the copper carbonate was applied in suspension an ounce was first well stirred 
in a small quantity of water and the mixture thus formed was added to 12| gallons 
of water. 
The sulphur powder was used according to the directions on the package, i.e., 10 
pounds were added to a barrel of water and allowed to stand a few hours before use. 
The yellow colored liquid resulting was employed without dilution. As the barrel 
became nearly empty it was again filled with water and the solution used as before. 
The mixture No. 5 was used as suggested by you, viz, 12 ounces to 22 gallons of 
water in the first two treatments, but ow r ing to injury to the foliage it was diluted 
one-third in the later sprayings. 
The trees selected for the experiment were of medium size, and all promised a full 
crop of fruit, though as appears from the table on a succeeding page, all did not 
mature a full crop. None of the trees used in the experiment of 1889 were employed in 
the experiment here reported. The first treatment was given on May 5, and others 
were made May 13, 31, June 5, 16,28, July 14, 25, August 6, 19, aud September 2. 
Of course all the trees were not treated at all the sprayings. The treatment of 
June 5 was intended to supplement that of May 31, much rain having fallen between 
these dates. As the apples showed indications of maturity the entire crop on each of 
the trees selected for the experiment was gathered and assorted into three qualities 
as follows: 
(1) Fruits quite free from scab. 
(2) Fruits showing scab spots but not of sufficient size or number to distort the 
apples. 
(3) Fruits more affected. 
