PICKERING SPRAYS. 37 



from a barium- water spray containing 0.6 per cent of copper sulphate, 

 or from standard Bordeaux, 4-4-50. The amount of bitter rot on 

 the sprayed trees was so small that no definite control results were 

 obtained. 



The data on the control of bitter rot by Pickering (A) and (C) 

 sprays are rather limited, notwithstanding the fact that the experi- 

 ments extended over three seasons. However, 0.5 per cent of copper 

 sulphate present in either Pickering (A) or (C) spray gave indica- 

 tions of satisfactory control of fungous diseases. 



The Pickering (A) spray is too caustic for use on the apple. While 

 less caustic than Pickering (A) sprays, the Pickering (C) sprays 

 seem to be more caustic than standard Bordeaux. It is apparent 

 that these sprays are more caustic than standard Bordeaux, and can 

 not be used on the apple. 



The barium-water spray was tested but one season on the apple. 

 While the results were satisfactory with respect to the absence of 

 injury, so little bitter rot was present on any of the trees that season 

 that no definite control results were obtained. 



Additional experiments are necessary to determine whether a 

 Pickering spray containing more limewater than is required in For- 

 mula C and the barium-water spray may be safely and efficiently 

 used as a fungicide on the apple. 



cranberries. 



Control of Fungous Diseases. 



IN 1917. 



Two Pickering (A) sprays and two Pickering (C) sprays were 

 tested on Centennial cranberries in 1917 at Hanover Farms, N. J. 

 The percentage of copper sulphate in the four sprays varied from 

 0.32 to 0.62. In addition, Bordeaux, 2^-1^-50, 2^-2^-50, and 

 '4-3-50, sprays were used. The first two Bordeaux sprays were 

 taken for the purpose of comparing the different amounts of lime in 

 a Bordeaux spray with the amount in a Pickering spray of the same 

 copper sulphate content (0.64 per cent). 



The sprays were applied to small plats, 132 feet long and 81 feet 

 wide, with a hand-pump sprayer, four times during the season, June 14 

 (three or four days before full bloom), June 27 (10 days after full 

 bloom), July 13, and July 30. Rosin-fish-oil soap, at the rate of 2 

 pounds to 50 gallons, was mixed with all the sprays. The berries w sre 

 picked September 15 and sorted for rot soon afterwards. 



