29 FUMIGATION OF APPLES FOR SAN JOSE SCALE. 
fully packed and the “iron header’’ put in place, the open end down. 
The single examination, made December 29, of fruit from the three 
parts of the barrel included 2,290 scales, of which 10 were doubtfully 
dead. In Nos. 41 and 42, fumigated December 1, the usual com- 
mercial apple box was used, in the former the fruit being unwrapped, 
and in the latter wrapped with the paper usually employed for this 
purpose. In both cases the fruit was examined twice (December 19 
and 31) and all scales were found dead. With this variety, how- 
ever, namely, Rhode Island Greening, from western New York, there 
was marked injury to the fruit from the gas. This injury was evi- 
denced by a browning or “scalding’’ of the skin, especially around 
the calyx end of the fruit, including the calyx basin and adjacent 
parts. Plate II, figure 2, shows the color and locality of typical gas 
injury to this variety, which very closely resembles the ordinary cold- 
storage “scald.” 
VARIETY-OF-FRUIT SERIES. 
To test the susceptibility of various varieties of apples to gas injury 
a miscellaneous collection was secured from the market in Washing- 
ton. The origin of the fruit was not known, and it was free from the 
San Jose scale. About one peck of apples of each sort was used, 
placed in one-third bushel baskets, and to each basket were added 
20 badly infested Baldwin apples, to determine the effect of treat- 
ment on scales. Three of the baskets were placed in each fumi- 
gating box, and.the entire 15 thus exposed simultaneously. The 
varieties used and other details are given in Table VI. 
TaBLeE VI.—Effect of hydrocyanic-acid gas on different varieties of apples. Exposure, 
one hour; potassium. cyanid used, 0.30 gram per cubic foot. ( Variety series.) 
/ 
| 
Experi- | Rate at Length ae | : 
aS ote re Kind of which potas- Effecton| Effect on 
wey Variety of apple. package. sium cyanid ores Seales scales. | fruit. 
ie was used. P oh Saal 
| 
Gr. per cu. ft. Hours. | 
olmiants wee tes sees 1-bu. basketa) » 0.30 1 1,037 | Alldead.| No injury. 
Wellowsbeliiiowenrs ss s4|— se doce 0. 30 Ih) SOs =sClOsl ss - Do. 
alla tere reser eee dole 0.30 eS ON adores Do. 
[AWAIT CS 2p See ete nee ene [Rrascee dors 0.30 1 POO ee oko = } Do. 
MAMEUSC Rese ee eee Pees dolarae= 0. 30 iL 950) jez =doresaee | Do. 
Morkelimperialy=- a= sees | eee Gorasnees 0. 30 1 89le es douras Do 
IBenubawiseas 2-55 Se eee do.a.._.. 0.30 1 986) 5 doz Do 
bay (eal DEN Ea Os 2 eee or ane loos be 0:0: === 0. 30 1 7508 |e aedossee Do 
IROUNG US Weels== = ss-6- eee | se ee Gotan 0.30 Li penl 21 Oy ead oncaee Do 
Rhode Island Greening....|...-- do.@..... 0. 30 1 O40) a2 sdokca= Do 
INOntherS Dyess See eee do.@....- 0. 30 Dy yl9oe secdorssse Do 
Kin Gere saan he ne Anam do.@__._: 0.30 1 967 |=. dor. = Do 
Grimes: Goldene sss 22-53 | sees doen 0.30 1 O1OR esd osess Do 
JERPIKG Kyi a eh ea aoe sneer |e COs 0.30 fi le AO Ree does Do 
1 750 |2 doz Do 
Peck#Pileasanttss 3 soe aa acloeee OKO S a Ss 0. 30 
| 
a In each basket were also placed 20 scale-infested Baldwins to determine effect on scales. Apples from 
Center Market, Washington, D. C. 
Fumigation was done November 30, 1906, and the fruit was kept 
under observation for several weeks. No gas injury whatever 
developed and, as will be noted, all the scales on the infested Bald- 
wins were killed. The absence of injury to the Rhode Island Green- 
