CONTROL OF THE GRAPE-BERRY MOTH. 



25 



EXPERIMENT IN THE MOORHEAD VINEYARD, MOORHEADVILLE, PA., 1916. 



An experimental plat of 48 rows, 8 rows per acre, was chosen in 

 this vineyard. It was divided into 6 plats of 8 rows each. During 

 the season of 1915 the infestation was heavy, 30 to 35 per cent of the 

 berries being "wormy," with a tendency for heaviest infestation at 

 the west side. Accordingly a transverse check of seven unsprayed 

 vines at the end of each row was left. The arrangement of plats is 

 shown by the diagram (fig. 8). 



Table 16. — Spray mixture used and methods and dates of application, Moorhead vine- 

 yard, Moorheadville, Pa., 1916. 





Date 

 sprayed. 



Arsenate 

 of lead 

 (pow- 

 der.) 



Bordeaux mixture. 



Laundry 

 soap. 



Potash 

 fish-oil^ 

 soap. 



Soft 

 soap. 



Water. 



Method 



Plat No. 



Lime. 



Copper 

 sulphate. 



of appli- 

 ation. 



I 



July 8, 19 

 ...do 



Pounds. 



is 



» 

 11 



1| 



li 



Pounds. 

 3 



3 

 3 

 3 



3 

 3 



Pounds. 

 3 



3 

 3 

 3 



3 

 3 



Pounds. 

 1 



1 



Pounds. 



Pounds. 



Gallons. 

 50 



50 

 50 

 50 



50 

 50 



Trail- 



II 







ers." 

 Do. 



III... . 



July 8,20 

 ...do 



2 





Do. 



IV 



1 







V 



...do 





1 



• z 1 e s" 

 first 

 appli- 

 cation ; 

 "trail- 

 e r s" 

 second. 



"Trail- 



VI 



July 20. 



1 





ers." 

 Do. 











Table 17. — Percentage of infestation in experimental plats, Moorhead vineyard, Moor- 

 headville, Pa., 1916. 





Number 



of 



vines. 



Number 



of 

 clusters. 



Total 

 berries. 



First brood. 



Second brood. 



Plat No. 



Infested 

 berries. 



Infesta- 

 tion. 



Infested 

 berries. 



Infesta- 

 tion. 



i ; 



20 



6 

 20 



6 

 20 



6 

 20 



6 

 20 



6 

 20 



6 



850 

 253 

 675 

 226 

 709 

 195 

 638 

 235 

 703 

 224 

 709 

 154 



' 29, 750 



9,108 

 23, 625 



8,136 

 23,397 



7, 410 

 19, 778 



8,930 

 23, 902 



8,064 

 20, 561 



4,312 



243 

 406 

 154 

 297 

 152 

 340 

 163 

 345 

 190 

 - 174 

 333 

 86 



Per cent. 

 0.81 

 4.45 



.65 

 3.65 



.64 

 4.57 



.82 

 3.86 



.79 

 2.15 

 1.61 

 1.99 



1,752 



3,812 

 949 

 2,997 

 806 

 2,848 

 1,307 

 2,443 

 4,605 

 2,741 

 1.079 

 1,010 



Per cent. 

 5.88 



Check I 



41.85 



II 



4.02 



Check II 



36.83 



Ill 



3.15 



Check III 



38. 43 



IV 



6.61 



Check IV 



27.33 



V 



19.60 



Check V 



33.99 



VI 



5.25 



Check VI 



23.39 







The final counts showed satisfactory results in plats where two 

 applications with "trailers" were made with poison and laundry 

 or fish-oil soaps (Plats I, II, III). Fish-oil soap without resin as 

 well as laundry soap was an effective adhesive, fish-oil soap having the 

 advantage. A "soft soap" was also used (Plat V), but proved a 



