228 INTERNATIONAL CONGRESS OF VITICULTURE 



Some of these results appear almost contradictory, but the infestation 

 in different parts of a vineyard varies considerably. When the grapes receive 

 the two sprayings in June and the third spraying is made early in July, the 

 infestation often seems to be worse where the grapes received the three 

 sprayings. Unsprayed plots will often have scarcely any berries left on the 

 bunch as all of the earlier infested berries split open and fall off. In the 

 sprayed plots many of the injured berries do not fall off and hence count 

 for a much greater infestation than really exists. 



1913. 



After a lapse of several years experiments for the control of the grape 

 berry worm were made again in 1913 in the East Cleveland district. The 

 grapes in 1913 bloomed at least a week later than they normally do in this, 

 locality. The usual dates being about June 5 to 10, while they did not 

 bloom until the 16th to the 20th of June in 1913. The set of fruit was also 

 very light, which seems to make suitable conditions for a very wormy crop 

 of grapes. Light crops of grapes, when unsprayed, are seemingly always 

 badly injured by the berry worm as there is a full quota of berry moths and 

 only half or less the number of berries to attack. This results in serious 

 injury wherever the berry worm is abundant. 



The plots selected were located on almost level land and each plot con- 

 sisted of about two-thirds of an acre of grapes. The larger part of this sec- 

 tion were Concords, but the plots included some Catawbas, Delawares and 

 Niagaras. A series of different sprays was used, applying the poison at 

 different strengths, using it with and without Bordeaux (2-3-50) and also 

 without soap, with soap and with Bordeaux and soap, in order to compare 

 the effectiveness of the poison in different combinations. The results are 

 given below with data concerning the treatment of the plots. 



Plot 1 Concords. 



Power sprayer, 200-pound pressure, about 130 gallons of spray per acre. 



Sprayed June 9-12. Arsenate of lead, 3 pounds; copper sulphate, 3 

 pounds; hard soap, 1 pound; lime, 4 pounds; water, 50 gallons. 



Sprayed June 24-27, 145 gallons per acre. Same as first application, ex- 

 cepting the heavier spraying. 



Sprayed July 15-18, 180 gallons per acre. Arsenate of lead, 4 pounds; 

 copper sulphate, 3 pounds; lime, 4 pounds; hard soap, 1 pound; water, 50 

 gallons. 



Counted September 10-11, 1913. Number of bunches, 31; sound berries, 

 682; wormy berries, 271; per cent wormy, 26.7. 



Plot 2 Concords. 



Power sprayer, 135 gallons per acre. 



Sprayed June 9-12, 1913. Arsenate of lead, 3 pounds; copper sulphate, 3 

 pounds; lime, 4 pounds; water, 50 gallons. 



Sprayed June 21-27, 145 gallons per acre. 



Arsenate of lead, 3 pounds; copper sulphate, 3 pounds; lime, 4 pounds; 

 water, 50 gallons. 



Sprayed July 14-18, 180 gallons per acre. 



