PICKERING SPRAYS. 31 
As only two barrels of sound apples were obtained from the 27 trees, 
it is apparent that none of the sprays controlled the bitter rot in 1916. 
Although the apples from the trees sprayed with Bordeaux did not 
show as much rot as those from the trees sprayed with Pickering 
sprays or from the check trees, practically every apple from the 12 
Bordeaux-sprayed trees was affected to some extent with bitter rot. 
The failure of any of the sprays to control the bitter rot may be 
explained by the fact that the rot was severe that season, as well as 
by the fact that no spray was applied to the trees after July 27. 
IN 1917. 
Three trees from each of three plats were treated with Pickering (A) 
and (C) sprays, containing 0.50, 0.25, and 0.13 per cent of copper 
sulphate. Bordeaux, 4-4-50, was employed as the standard spray. 
Two trees were sprayed with Bordeaux, 2-2-50, and two with Bor- 
deaux, 2-1-50, sprays, in order to determine the effect of decreasing 
the lime on the fungicidal action of the copper. Several unsprayed 
trees were left as controls. The sprays were applied with a power 
sprayer four times, June 4, June 22, July 9, and August 2. On August 
2, because of injury caused by the sprays, the spray was applied to 
but one tree of plats A 1? A 2 , A 3 , B x , B 2 , B 3 , and to but one of those 
sprayed with Bordeaux, 2-1-50. On August 30, counts were made 
of all dropped fruit. All fruit on the trees was picked between Sep- 
tember 14 and 18, and counted for rot and for a late type of Bordeaux 
injury or russeting which developed between August 30 and Sep- 
tember 13. The results are shown in Table 10. 
Scarcely any bitter rot was present in the orchard in 1917. Con- 
sequently, the results prove very little concerning the relative fungi- 
cidal value of the sprays tested. On plat B 3 , the tree sprayed with 
Pickering solution was the only one of the sprayed trees which showed 
any amount of rot, the other two trees of that plat being practically 
free from rot. 
IN 1918. 
Pickering (C) spray and a barium-water spray, similar to the one 
used on potatoes with excellent results (page 11), were used on Cheese 
apple trees. Ten gallons of the barium-water spray were prepared 
by dissolving 8 ounces of barium hydrate in 9 gallons of water and 
adding 2 quarts of copper sulphate stock solution (1 pound per 
gallon), diluting to 10 gallons with water, and stirring thoroughly. 
The Pickering (C) spray was prepared according to the directions 
given on page 7. A Bordeaux, 4-4-50, spray was the standard 
spray. Two trees were sprayed with the Pickering spray, two with 
the barium-water spray, and two with standard Bordeaux, while 
one tree was left unsprayed. The sprays were applied with a power 
sprayer on June 14, June 28, July 26, and August 13. 
