SPRAYING PLUMS AND CHERRIES. 217 
Curculio injury on all of the plats was severe. On the check there 
was only 28.55 per cent of fruit free from punctures and infestation. 
On the plat sprayed 3 times, 61.67 per cent of the plums were sound, 
a gain in sound fruit over the check of 33.12 per cent. Two applica- 
tions gave a gain of 11.15 per cent and the single treatment showed 
an increase over the check of 18.37 per cent, a difference doubtless 
due to location. A more exact idea of the commercial benefits of 
spraying, however, may be had by a consideration of the relative 
amount of ripe fruit at picking time showing the punctures of the 
insect, as being more or less deformed and unsalable, for it will be 
understood that not all ripe fruit showing punctures is unsalable. 
On the check plat (IV) of the ripe fruit at picking time 66.58 per cent 
were punctured, as against 24.48 per cent on Plat II, receiving 3 
applications. Plats I and II show about the same amount of punc- 
turing on the ripe fruit, namely, 39.41 and 41.20 per cent, respectively. 
During 1906, at North East, Pa., an orchard of about two hundred 
16-year old plum (York State prune) trees were sprayed by Mr. 
Johnson, using Bordeaux mixture plus 3 pounds arsenate of lead. 
Through an error only one tree was left unsprayed for comparison. All 
of the fruit throughout the season was carefully examined from this 
tree and an adjacent unsprayed tree, and the results are shown in 
Table CVII. Previous to this season the owner had followed the 
jarring method, but by reason of the favorable results spraying was 
subsequently followed. 
This same orchard was sprayed during the following year by Mr. 
Johnson, and results taken on five sprayed and five unsprayed trees 
are shown also in the table. 
Tasir CVII.—Results of spraying York State prunes for the plum curculio during the 
seasons 1906 and 1907, North East, Pa. 
1906. 
: : & ! ; Sis 
Fruit from ground. Fruit from tree. g ae a= 3 q 
7 
= feta oes |e Ho} ge ee 
; = Ssolsd| uy | 2 s 
Trees. Treatment. + 5 | ® ; 2g &S q | Saat 
5 Le! | Sic a = 4] ° = = 
sa s oe Se ea | cs! ie ical (eee 2 a | 
5 2 q ra a | 2 q 3S 3 3 3 a s 
Be cee baal) | et Bear ho ee SiS he 
am ie n = | 73) a a a is = a 
1 | Three treatments, 448} 393] 1,207) 1,655) 69) 0} 1,640) 1,709} 517; 393] 2,847] 3,364] 84.63 
Bordeaux m i x- 
ture (44-50) plus 
3 pounds arsenate 
of lead: May 25, 
June 7 and 19. 
One untreated..... 1,621/1, 446} 532] 2,153) 272) 0; 470] 742) 1,893) 1,446} 1,002) 2,895) 34.61 
| 
5 | Twoapplications,}] 435) 344) 6,933] 7,368) 14 0 9, 559] 9,573 449 344/16, 492.16, 941) 97.35 
Bordeaux mix- 
ture (44-50) plus 
3 pounds arsenate 
of lead: June 8 
and July 3. 
Five untreated... .- 581; 490; 7,481) 8,062) 57 0} 8, 153} 8,210 638 490/15, 634 16,272) 96.08 
| 
