198 
THE PLUM CURCULIO. 
Orchard of the Straihmore Orchard Co. — In the Strathmore orchard, 
at Mount Jackson, the curculio was notably more abundant, and the 
results were less favorable. The orchard had been in sod for some 
years and conditions were thus favorable for the insect. All trees 
not included in the experiment were sprayed by the owners. 
The results indicate the impracticability of satisfactorily reducing 
curculio injury by spraying alone, when conditions are extremely 
favorable for the insect. Three applications protected the fruit to 
an extent of 40.82 per cent as against 27.23 per cent on the unsprayed 
trees, a gain of 13.59 per cent of the crop. Curiously, the single 
application, given to Plat II, resulted in a higher percentage of sound 
fruit than the three treatments given to Plat I, namely, 57.90, an 
increase over the check plat of 30.67 per cent. 
TableXCIX. — Results of spraying apples/or the plum curculio , Mount Jackson, Va.,1909. 
Plat 
No. 
Treatment. 
Variety. 
Tree 
No. 
Total 
num- 
ber of 
apples. 
Total 
num- 
ber of 
apples 
punc- 
tured. 
Total 
num- 
ber of 
punc- 
tures. 
Per- 
centage 
of sound 
apples. 
Aver- 
age per- 
centage 
ofsound 
apples. 
I 
("Three applications Bordeaux mix- 
1 ture (1-1-50) plus 2 pounds ar- 
| senate of lead, Mav 6-7, 28-29, 
[ July 8-9. 
[One spraying only, with arsenical. 
Drenched with arsenate of lead, 
2 pounds to 50 gallons of water, 
May 6-7. Bordeaux mixture 
only (2-2-50), applied May 28-29 
[ and July 8-9. 
iBen Davis.. 
do 
.do. 
1 
2 
3 
4 
5 
6 
8 
r i 
2 
3 
4 
5 
6 
7 
8 
1 
2 
3 
4 
5 
6 
8 
1,866 
1,308 
3,466 
708 
1,667 
3,786 
1,063 
2,429 
1,367 
755 
1,631 
441 
1,257 
2,197 
612 
1,382 
2,961 
2,391 
3,067 
932 
3,013 
4,040 
1,486 
2,869 
26. 74 
42.28 
52.94 
37.71 
24.59 
41.97 
42.42 
43.10 
16,293 
9,642 
20,759 
40.82 
II.... 
3,827 
3,657 
675 
989 
1,679 
3,480 
969 
4,299 
1,507 
1,788 
303 
494 
754 
1,212 
447 
1,735 
2,7S2 
1,800 
633 
1,032 
1,449 
2,159 
987 
3,153 
00. 62 
51.10 
55. 11 
50.05 
55.09 
65. 17 
53.86 
59.64 
19,575 
8,240 
13,995 
57.90 
III... 
3,926 
3,109 
1,840 
1,508 
3,189 
4,153 
5,121 
2', 795 
3,186 
2,226 
1,079 
1,226 
2,399 
2,823 
3,611 
2,107 
7,336 
4,497 
2,212 
2.888 
5,030 
6,122 
8,779 
4,904 
18.84 
28.40 
41.36 
18.69 
24.77 
32.04 
29.48 
24.61 
25,641 
18,657 
41,768 
27.23 
EXPERIMENTS AT ST. JOSEPH, MO. 
The work at St. Joseph also formed part of a demonstration sched- 
ule of spraying in comparison with the one-spray method. The 
orchard used had been in sod for some years, and no spraying had 
been done. Conditions were especially favorable for the insects, 
and, as shown by the tabulated results below, the injury under these 
conditions was very severe. The crop, moreover, was light by reason 
