CONTROL OF THE GRAPE-BERRY MOTH. 



23 



oil soap without resin (Plat VIII) , were used. The difference in in- 

 festation in these plats was so slight that it is not worthy of special 

 consideration. Resin fish-oil soap solution spread rapidly and could 

 be applied most easily. Arsenate of lead when used at the rate of 2 J 

 pounds (powder) to 50 gallons of liquid (Plat VI) did not appear more 

 effective than when used at the rate of 1^ pounds to 50 gallons. The 

 solution in which Bordeaux mixture was omitted (Plat VII) was 

 practically as effective as any other, although slight burning followed 

 its application. 



EXPERIMENT IN THE SOUTHWICK VINEYARD, NORTH EAST, PA., 1916. 



A plat of 28 rows, 9 rows to the acre, was chosen for experimental 

 purposes in this vineyard. An unsprayed check of 8 rows was left 

 in the middle of the plat. On one 

 side were two sprayed plats of 6 

 rows each, and on the other side 

 two plats of 4 rows each. The rest 

 of the vineyard section on either 

 side of the experimental block, 

 although sprayed for the grape 

 rootworm by the owner, also served 

 as a check. The arrangement of 

 these plats is shown by the diagram 

 (fig. 7). 



During the season of 1915 this 

 section had been heavily infested, 

 from 30 to 40 per cent, with a tendency for the infestation to be 

 heaviest at the north end. 



MO/?r& 



&ZZ7 



tVfST 



f/isr 



sours/ 



Fig. 7. — Diagram showing arrangement of ex- 

 perimental plats in the vineyard of Mr. B. T. 

 South wick, North East, Pa., 1916. The 

 sprayed plats are marked with Roman numerals 

 and the check plats with letters. (Original.) 



Table 14. 



-Spray mixtures used and methods and dates of application, Souihwick vine- 

 yard, North East, Pa., 1916. 





Date 

 sprayed. 



Arsenate 



of lead 

 (powder). 



Bordeaux mixture. 



Nicotine 



sulphate, 



40 per 



cent. 1 



Laundry 

 soap. 



Water. 



Method of 

 application. 



Plat No. 



Lime. 



Copper 

 sulphate. 



I 



July 10, 24. 

 do.... 



Pounds. 



2-2- 

 H 

 1* 



Pounds. 

 3 

 3 

 3 

 3 



Pounds. 

 3 

 3 

 3 

 3 



Pints. 



j 



X 



i 

 i 



Pounds. 

 1 

 1 

 1 

 1 



Gallons. 

 50 

 50 

 50 

 50 



"Trailers." 



II 



Do. 



Ill 



July 24.... 

 July 10, 24. 



Do. 



IV 







first . ap- 

 plication, 

 "Trailers" 

 second. 



i Last application only. 



