PICKERING SPRAYS. 29 



sprayer as a fine mist (Vineland, N. J.) about one-half as much cop- 

 per in proportion to that used in the spray adhered to the leaves as 

 when standard Bordeaux was used. When the Pickering sprays 

 were applied with a hand pump (Vienna, Va.), the ratio of copper 

 retained on the leaves was still further reduced in the case of the 

 Pickering sprays. 



The use of rosin-fish-oil soap with one of the Pickering sprays 

 proved advantageous in the Virginia tests, but not in the New Jersey 

 tests. 



Apparently the copper of the Pickering sprays exists in a more 

 active and available form than the copper of the Bordeaux spray, as 

 evidenced by the severe burning of the grape leaves. No differences 

 were detected in the caustic action or in the adhesive properties of 

 the Pickering (A) and (C) sprays. The caustic action and the fungi- 

 cidal properties of the sprays made by the two formulas were 

 apparently the same. 



The Pickering sprays seem to be too caustic for spraying grapes. 

 These sprays, however, may have a very definite use for the last 

 application when this must be made late in the season • after the 

 berries are half grown. Bordeaux spray applied late in the season 

 tends to remain on the berries, which is undesirable. Pickering 

 sprays, however, are nonstaining. 



Control of Fungous Diseases. 



An orchard of Yellow Newtown (Albemarle Pippin) trees at Green- 

 wood, Va., where bitter rot is prevalent, was selected for these 

 experiments. The orchard was not well cultivated and was famous 



as a place for bitter rot. 



in 1916. 



Of the 27 trees in the orchard 12 were sprayed with. Pickering 

 sprays, 12 with standard Bordeaux, 4-5-50, and three were left un- 

 sprayed. The sprays were applied three times, June 23, July 13, and 

 July 27. The Bordeaux spray was applied with a power sprayer 

 each time. The Pickering sprays were applied the first time with a 

 hand-pump sprayer and afterwards with a power sprayer. The 

 results of this work are shown in Table 10. 



