6 BULLETIN 959, U. S. DEPARTMENT OF AGRICULTURE. 
throughout the orchard. Plat III, in which three cover applications 
were made for the first brood and two for the later broods, produced 
the best crop of apples from the point of insect control, 72.22 per cent 
of the fruit being free from worms. Plat IV was treated with the 
same number of cover sprays as plat III, but the number of applica- 
tions for the broods was reversed, and with this treatment 66.48 per 
cent of the fruit was free from worm infestation. In plat V only 
three cover sprays were applied, and the treatment resulted in 62.21 
per cent of uninfested fruit. As previously noted, plat VI was 
sprayed five times by means of Vermorel nozzles with a pressure of 
but 90 pounds, producing a very fine mistlike spray. Generally 
speaking the results indicate that this treatment was as effective as 
the other methods employed, there being 63.78 per cent of worm-free 
fruit. The low-pressure mist spray also gave as good results as the 
high-pressure coarse sprays in preventing the entrance of larve 
through the calyx end of the apple. It should be borne in mind, 
however, that in commercial spraying a reasonably high pressure of 
200 to 250 pounds will increase the speed of the work and that the 
distribution of the spray material is likely to be more thorough than 
when applied under a low pressure. 
Arsenate of lime, both homemade and commercial, as used in plats 
VII and VIII, gave comparatively poor results. 
The unsprayed or check trees, plat X, were very wormy, giving 
but 13.51 per cent of fruit free from larve. 
-The sprayed fruit was well protected against the calyx entrance 
worms except in plat VIII. With this exception, the percentage of 
wormy apples infested at the calyx in the sprayed plats varied from 
3.72 to 5.92. The unsprayed plat produced 55.06 per cent of wormy 
fruit infested at the calyx. 
TABLE 4.—Summary of results of spraying for the codling moth, Johnson orchard, Grand 
Valley of Colorado, 1915. 
peel e | a. (a,~ lias ltpeceesver Eau ees 
selina} 839 CIBESS | Per cent of worms = aS 2 
|B ji2 |3 |S | Sq | Gncluding extra) * rpplestatested’= & |B eral 
=p) men t= Ba 5 = 2 | entering apples. | : eee te 
aja |Ssa|sa|sé | SB |S28| oP) Ba 
[RSS EES) Seo | 3 |ye| 2s | of 
| rem Uren esis ole) Sis rally Pe EAB tos. 
Plat. | 3S | 5§ Be | Es q 8 | S |'9%)581'ae 
| = |98)58 | 83/155 g Sq /Felsg 
pS ge] ee an) AB lo | : Shee S322 
— = | BS) |) axe ok x“ “ al : “ a ef |}s2o|] se 
5 go oD } mas] =) =| ical ° | == Ty) Lae a 
aries = pe had (ite ton ie ss) 2 Ss = = So ofS are S) 
pois) Ss 8 5 | & °) na ” rS) na 2 5 420 > Si 
= iS | © > > j; ~ ~~ ~ = p=) = | > =) (3) 
Zp VE A St mate et eet a ea eee |e | Aas | 
| | | 
Pee tere 5| 4,208] 2,952} 0.70] 1. 5a 2 a 97.43} 0.24) 3.72] 95.91] 0.38] 5,306, 1.26) 40.54) 55.87 
UR ee eS: 12} 9,356) 7,347; .79) 1.67) 3.17|96.49) .34] 5.29) 94.38 34/17, 873) 1.91) 33.56) 52.88 
1d eee 6) 2,192; 844 .39) 1.39) 3.44) 96.09) .47) 4.76) 94.58 66] 2,067; .94; 52.12) 72.22 
ee 5} 3,174) 1,523) .48) 1.43) 4.14) 95.40) .46) 5.92) 93.52) .56] 3,131, .99) 44.27] 66.48 
ae hs Sea 7{ 6,005) 3,567) .59) 1.57) 2.75) 96.92| .34) 4.32) 95.24) .44) 5,549) .92) 53.51) 62.21 
WEE ECR y 7| 3,708) 2,013) .54| 1.50) 3.87] 95.83) .30) 5.81] 93.89) .30) 3,450 .93) 48. 50} 63.78 
WIEFS 2S. 4) 1,785! 2,182) 1.22) 1.86, 2 38| 97.25} .37| 4.42] 95.15) .43] 2,098) 1.18) 56.49) 34.17 
VIiil 3) 1,601) 2,308) 1.44) 2.00) 6.50) 93.15) .35) 12.98) 86.76) .26) 1,320) .82) 52.36) 27.80 
DE 10| 7,613] 3,438] .45| 1.43] 3.72] 95.75} .52) 5.32} 94.18} .50| 7,337] . 96| 49. 39) 68. 41 
Xe oes 3} 2, pat 5, rate, 1.80} 2.08) 26.45) 72.31) 1. ig 55. 06) 43.87) 1.07 | a 90 4 13. 51 
