196 
THE PLUM CURCULIO. 
EXPERIMENTS AT SILOAM SPRINGS, ARK. 
In the one-spray versus demonstration treatments for the codling 
moth and apple diseases at Siloam Springs in 1909 special attention 
was given to determining the effect of these treatments on the cur- 
culio. The results from only Plats I, IV, and V are given as consti- 
tuting the principal features of the work. The orchard was an 
isolated one and contained 344 trees and was divided into five plats. 
There was a miscellaneous assortment of varieties, but principally 
Ben Davis, on which variety all counts were made. The treatments 
which the respective plats received are shown in Table XCVII. 
Plat I shows an increase in uninjured fruit over the unsprayed plat 
(Plat V) of 77.20 per cent, and there is a difference in favor of Plat 
IV of 3.74 per cent of sound fruit. It will be noted that one drench- 
ing spray in this instance gave somewhat better results than five 
applications, though this condition is probably to be accounted for 
by reason of the proximity of Plat IV to the check plat. 
Table XCVII. — Results of spraying apples for the plum curculio, Siloam Springs, 
Ark., 1909. 
Plat 
No. 
Treatment. 
Variety. 
Tree 
No. 
Total 
number 
of apples. 
Total 
number 
of apples 
punc- 
tured. 
Total 
number 
of punc- 
tures. 
Percent- 
age of 
sound 
apples. 
Average 
percent- 
age of 
sound 
apples. 
One spraying only with 
arsenical; drenched 
with arsenate of lead, 
1 pound to 50 gallons 
water, Apr. 24-25. Bor- 
deaux mixture only 
(4-4-50) May 25-26, 
July 2. 
Five applications Bor- 
deaux mixture (3-3-50) 
plus 2 pounds arsenate 
of lead: Apr. 24-25, 
May 25-26, July 2, 
July 22, Aug. 10. 
Unsprayed 
Ben Davis.. 
....do 
do 
( 1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
( 1 
2 
3 
4 
5 
6 
8 
9 
10 
11 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
. 13 
5.(is9 
4,813 
3, 796 
2,750 
3,446 
3,768 
3,307 
5,443 
3,644 
2,652 
3,895 
1,179 
915 
687 
387 
208 
532 
370 
706 
364 
216 
335 
1,979 
1,713 
2,613 
683 
268 
1,012 
638 
1,200 
642 
319 
642 
79.27 
80.98 
81.90 
85.92 
93.96 
85.88 
88.81 
87.02 
90.01 
91. S5 
91.39 
I. 
43,203 
5,899 
11,709 
86.34 
3,536 
1,890 
5,076 
1,665 
3,145 
1,665 
2,496 
3,172 
4,791 
1,957 
3,058 
746 
301 
437 
74 
266 
200 
498 
467 
1,656 
140 
769 
1,293 
562 
773 
98 
430 
432 
1,025 
S77 
3,129 
254 
1,429 
78.90 
84.07 
91.39 
95.55 
91.54 
87.98 
80.04 
85.27 
65.43 
92.84 
74.85 
IV.- 
32,451 
5,554 
10,302 
82.88 
2,560 
1,701 
995 
1,538 
1,206 
2,501 
2,821 
1,156 
2,323 
2,258 
1,719 
1,608 
2,060 
2,130 
1,595 
948 
1,522 
999 
2,299 
2,724 
1,070 
1,936 
2,117 
1,605 
1,517 
1,750 
6,623 
6,230 
4,331 
10,068 
3,372 
9,527 
14,727 
4,714 
6, 143 
8,707 
6,921 
5,984 
6,739 
16.79 
6.23 
4.72 
1.04 
17.16 
8.07 
3.43 
7.43 
16.65 
6.24 
6.63 
5.65 
15.04 
v.... 
24,446 
22,212 
94,086 
9.14 
