CONTROL OP THE GRAPE-BERRY MOTH. 



21 



The final counts show that the grape-berry moth had been con- 

 trolled in all sprayed plats. In this respect they contrast sharply 

 with the previous season's results in the same vineyard. The only 

 essential differences between the treatments of this season and those 

 of the previous one were the addition of soap to the spray mixture 

 and the application of the spray with "trailers" instead of with 

 "set nozzles." 



The results further indicate that 3 pounds of arsenate of lead 

 (paste) was practically as effective as 5 pounds to 50 gallons of 

 liquid, and that no special advantage or injury resulted from the 

 addition of nicotine sulphate to the spray mixture. Also that 

 drawing the sprayer in every alley and each rodman spraying only 

 one side of a row at a time had no advantage over driving up alternate 

 alleys with each rodman spraying both sides of a row at one time. 



Spraying Experiments in 1916. 



Confirmation of the 1915 results was the most important feature 

 of the season's work. Although infestation by the grape-berry moth 

 was much heavier, the season was more favorable for work and 

 the control measures were more effective. 



EXPERIMENTS IN THE BARTLETT VINEYARD, NORTH EAST, PA., 1916. 



The experimental work in Mr. A. P. Bartlett's vineyard was con- 

 ducted in two sections differing in distribution of the berry moth. 

 In both sections the rows ran north and south, but the checks were 

 arranged differently. In the upper section the 1915 infestation was 



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Fig. 6.— Diagram showing arrangement of experimental plats in vineyard of Mr. A. P. Bartlett, 

 North East, Pa., 1916. In the lower vineyard the sprayed plats are marked with Roman nu- 

 merals and the check plats are lettered. (Original.) 



much the heavier on the west side, consequently the checks were 

 not chosen in the usual way but instead a transverse check of the 

 end 6 vines on all rows was left unsprayed. The arrangement of 

 plats is shown by the diagram (fig. 6). 



