PICKERING SPRAYS. 



23 



3-3-50, spray, containing 0.75 per cent of copper sulphate. A 

 Pickering (A) spray containing 0.38 per cent of copper sulphate was 

 used alone and in combination with rosin-fish-oil soap. One plat 

 was held unsprayed as a check plat. The sprays were applied on 

 May 18, May 27, June 15, and July 7, 1916. A power sprayer was 

 used for each spraying with the Bordeaux and for the May sprayings 

 with the Pickering spray, while a hand-pump sprayer was employed 

 for the June and July applications of the Pickering spray. Because 

 of injury to the vines sprayed with the strongest Pickering solutions 

 after a severe hail storm occurring on June 11, no further applica- 

 tions of these sprays were made. The spraying of one or two rows of 

 grapes with the weaker Pickering sprays was, however, continued 

 throughout the season. 



Table 6. — Effect of various sprays on blight and yield of grapes (New Jersey). 





Spray used. 



Cop- 

 per 

 sul- 

 phate 



in 

 spray. 



Condition of fruit when 

 picked. 



Net 

 weight 



of 

 grapes 

 picked 

 from 

 two 

 rows. 





Plat 



No. 



Sound. 



Black 

 rot. 



Downy 

 mil- 

 dew. 



Total 

 dis- 

 eased. 



Spray injury noted June 13. 



1 



2 



Pickering (A) 



do 



Per ct. 

 0.64 



.38 



.38 



.13 

 .13 

 .065 

 .23 



.23 



.115 



.36 



.75 



Per ct. 

 0) 



0) 



C 1 ) 



76.12 

 71.68 

 69.63 



0) 



0) 



85.09 

 0) 



92.91 



.00 



Per ct. 



0) 



C 1 ) 



21.17 



25.00 

 25.98 



C 1 ) 



C 1 ) 



12.43 

 0) 



6.79 

 70.64 



Per ct. 



0) 



C 1 ) 



2.71 

 3.33 

 4.39 

 (») 



0) 

 1.48 



C 1 ) 



.29 

 37.53 



Per ct. 

 0) 



0) 



0) 



23.88 



28.33 



30.37 



0) 



C 1 ) 

 14.01 



C 1 ) 



7.02 

 100. 00 



Lbs. 

 121 



411 



784 



961 

 1,501 



949 



1,502 



892 



1.375 

 830 



Leaves and fruit greatly 

 injured; many buds de- 

 stroyed. 



Almost complete defolia- 

 tion: part of fruit de- 

 stroyed. 

 Do. 



Leaves noticeably injured. 



Do. 

 Leaves slightly injured. 

 Large proportion of leaves 

 destroyed. 



Do. 



2 



3 



3 



4 



Pickering (A) and 

 rosin-fish-oil soap. 



Pickering (A)* 



do. 3 



do 



5 



5 



do 3 



6 



do 



Leaves slightly injured. 

 Large proportion of leaves 



destroyed. 

 Leaves slightly injured. 



7 



do..... 



Check. . 



Bordeaux, 3-3-50 











1 Fungus control satisfactory. 



2 Spray applied three times. 



3 Spray applied to first two rows four times. 



The results for the control of fungous diseases in New Jersey 

 (Table 6) indicate that the control of disease was in direct proportion 

 tp the spray injury of the vines. Apparently the strongest Picker- 

 ing spray, which contained 0.64 per cent of copper sulphate (plat 1), 

 controlled the fungous diseases more effectively than the Bordeaux 

 sprays, showing the high availability of the copper of the Pickering 

 sprays. The injury, however, was so severe that the "spray could 

 not be used commercially. 



IN VIRGINIA. 



Two acres of grapes, largely Concords, in poor condition, in Vienna, 

 Va., were sprayed with Pickering sprays and with a standard Bor- 



