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. v 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 t , A 2 , A 3 , B 1; 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. 



