CONTROL OP THE GRAPE-BERRY MOTH. 



17 



s 



Z7 



£r 



HP 1 



Hsfsr 



been employed. Tables 6 and 7 will give in detail the treatments 

 applied in the different vineyards and the results as shown by per- 

 centages of "wormy" fruit. 



EXPERIMENT IN THE BARTLETT VINE- 

 YARD, NORTH EAST, PA., 1915. 



Experimental work in this 

 vineyard was conducted in a 

 square corner section of about 

 2 acres which had been very 

 heavily infested in 1914. It 

 was divided into two large 

 plats of 11 rows each with an 

 8-row check between and 2 

 narrow plats of 3 rows each 

 outside of the larger ones. 



£XS7- 



soc/rs/ 



Fig. 3. — Diagram showing arrangement of experimental 

 plats in the vineyard of Mr. A. P. Bartlett, North East, 

 Pa., 1915. The sprayed plats are marked with Roman 

 numerals and the check plats with letters. (Original.) 



The adjacent vineyard also was unsprayed and used as a check, 

 arrangement of plats is shown in the diagram (fig. 3). 



The, 



Table 6. — Spray mixtures used and method and dates of application in experimental 

 plats, Bartlett vineyard, North East, Pa., 1915. 





Dates of 

 spraying. 



Arsenate 

 of lead 

 (paste). 



Bordeaux mixture. 



Laundry 

 soap. 



Nicotine 

 sulphate. 1 



Water. 



Method 

 of appli- 

 cation. 





Plat No. 



Lime. 



Copper 

 sulphate. 



Remarks. 



I 



II 



July 6,19 

 ...do 



Pounds. 

 3 



3 



5 



5 



Pounds. 

 3 



3 



Pounds. 

 3 



3 



3 



3 



Pounds. 

 1 



1 



1 



1 



Pints. 



i 



I 



i 



4 



1 



Gallons. 

 50 



50 



50 



50 



Trailers . 



...do 



...do 



...do.... 



Double 

 sprayed. 2 

 Single 



Ill 



rv.. 



...do 



...do 



sprayed. 2 

 Single 

 sprayed. 2 







sprayed. 2 



i Last application only. 



2 Plats marked "double sprayed" were sprayed twice on each date of treatment, the seconu spray being 

 applied as soon as the first had dried. 



Table 7. — Percentage of infestation in experimental plats, Bartlett vineyard, North East, 



Pa., 1915. 





First brood. 



Second brood. 



Plat No. 



Num- 

 ber of 

 vines. 



Num- 

 ber of 

 clus- 

 ters. 



Total 

 berries. 



Infested 

 berries. 



Infes- 

 tation. 



Num- 

 ber of 



vines. 



Num- 

 ber of 

 clus- 

 ters. 



Total 

 berries. 



Infested 

 berries. 



Infes- 

 tation. 



I 



20 

 20 

 20 

 20 

 20 

 20 

 20 



1,024 

 1,132 

 1, 124 

 1,330 

 1,192 

 1,051 

 832 



29,036 

 31,314 

 30, 568 

 38,676 

 41,107 

 29, 567 

 21,356 



572 



572 



2,404 



375 



124 



1,943 



1,743 



Per cent. 

 1.97 

 2.71 

 7.86 

 .97 

 .30 

 6.57 

 8.16 



15 

 15 

 15 

 15 

 15 

 15 

 15 



768 

 849 

 843 

 997 

 894 

 788 

 624 



21, 760 

 23,489 

 22, 926 

 29,066 

 30,830 

 22, 175 

 16, 016 



849 



963 



3,372 



313 



68 



3,925 



1,399 



Per cent. 

 3.9 



II.... 



4.1 



Check A 



III.. 



14.8 

 1.2 



rv 



.23 



Check B 



Check C 



17.7 

 46.2 







87069°— Bull. 550—17- 



