KEMEDIAL MEASURES. 



77 



The ground was plowed early in May and received three thorough 

 cultivations during the summer. It should be observed at this 

 point that this is by no means an attempt to solve the problem of 

 vineyard fertilization, which belongs to the province of the horticul- 

 turist, and that the results obtained on these plats are presented 

 without comment upon this feature of the experiment, leaving the 

 reader to draw his own conclusions. 



With the appearance of the first beetles all of the plats except the 

 check plat received a thorough spraying with Bordeaux mixture and 

 arsenate of lead, using the following formula: Copper sulphate, 4 

 pounds; quicklime, 4 pounds; arsenate of lead, 3 pounds. A 

 second spraying with the same ingredients was made ten days to 

 two weeks later. (See exact dates on Table XXIX, showing egg 

 deposition.) 



Table XXIX. — Effect of poison spray against the grape root-ivorm as shown hy relative 

 occurrence of eggs on sprayed and unsprayed plats of the Porter vineyard during 1907, 

 1908, and 1909, at North East, Pa. 



UNSPRAYED PLAT. 



Year 



When exam- 

 ined. 



Number of egg clusters found. 



Esti- 

 mated 

 num- 

 ber 

 of eggs. 



Num- 

 ber 

 of 



vines. 



Num- 

 ber 

 of 

 canes. 



Average num- 

 ber of eggs. 



Date of 

 spray 



Large. 



Medi- 

 um. 



Small. 



Total. 



Per 



vine. 



Per 

 cane. 



applica- 

 tion. 



1907 



Aug. 12,1907 

 July 22,1908 

 July 21,1909 



97 

 45 

 37 



150 

 91 

 56 



238 

 78 

 94 



485 

 214 

 187 



11, 730 

 5,760 

 4,470 



25 

 25 

 25 



76 

 76 

 97 



469.2 

 230. 4 

 178. 8 



154. 37 

 78.9 

 46.08 





1908.. 

 1909 









SPRAYED PLAT. 

 Formula: 4 lbs. blue vitriol (copper sulphate), 4 lbs. lime, 3 lbs. arsenate of lead, 50 



1907.. 



1909. 



Aug. 13,1907 



1 



21 



34 



56 



1,440 



25 



50 



57.6 



25.7 



July 22,1908 







10 



4 



14 



340 



25 



58 



13.6 



5.8 



July 21,1909 



3 



8 



7 



18 



460 



25 



117 



18.4 



3.9 



July 13 



Julv 22 



/June 24 



\July 2 



July 5 



July 16 



The spray applications were made with a gasoline-engine spraying 

 outfit specially mounted for vineyard work (PL X, fig. 2) having an 

 arrangement of fixed nozzles, three on each side, the two lower of 

 which throw the spray on the side of the vines as the machine passes 

 through the rows. The upper nozzle reaches out over the top of the 

 row throwing the spray downward so that it covers the new growth 

 at the top of the trellis. This downward direction of the spray to 

 cover the new growth at the top of the trellis is highly desirable since 

 the beetles exhibit a tendency to feed more freely on this new growth, 

 especially after the lower leaves have been coated with a poison spray. 

 A pressure of from 100 to 125 pounds was maintained throughout 



