STRENGTH-OF-GAS EXPERIMENTS, 1906-7. IU 
Taste I].—Condition of San Jose scale on unfumigated apples during the winter of 
1906-7. 
For comparison with condition of scale on fumigated fruit. 
Date of examination. 
| Variety of apple. 
alive. | dead. 
ber ber cent 
of of of 
scales | scales | scales 
Remarks. 
November 12, 1906. .-- 
November 26, 1906... - 
December 13,1906. -_. 
February 20,1907... -- 
February 28,1907..... 
December 3,1906...-- 
December 14,1906... 
December 29, 1906... . 
January 14, 100K ee 
February 27, 1907-....- 
Rhode 
Greening. 
10 EP) in, LORS || ED 
10 533 le Ane | beas0 
10 360 640 | 36.00 
| 898 | 10.20 
Fruit kept in out-of-door store- 
house. 
Held in cold storage 4 weeks. 
After Dee. 3 in out-of-door 
storage house. 
STRENGTH-OF-GAS 
SERIES. 
From the first-mentioned or strength series of tests it was desired 
to obtain information on the strength of gas necessary to kill the 
scale, and incidentally the possible effect of these various strengths 
upon the fruit. 
The apples used were of the Baldwin variety, from 
western New York (Niagara County), and badly infested with the scale. 
, 1906, with fruit but a few 
days in cold storage from the orchard and perfectly dry when treated. 
Ordinary open market baskets were used, of about one-third bushel 
The fumigation was done November 12, 
capacity, and were nearly filled with the infested fruit. 
continued for forty-five minutes. 
Table ITI. 
Fumigation 
The essential details are given in 
Tasie III.—Hffect of different strengths of hydrocyanic-acid gas on scales and fruit. Ex- 
posure, forty-five minutes. 
(Strength series. ) 
= ; Rate at which) Number 
. ariety 0 potassium | of scales 
Experiment No.— | “apple. eyanid exam- 
was used. ined. 
Gr. per.cu. ft. 
Web Ser  al e Na Baldwin. .| 4 0. 05 3, 162 
DAE ca tty ee eee AAO eee): 0. 10 1, 426 
Aye eae re nee =O erene ae 0.15 1,678 
Aas be fF eae eee REOeee: mn! 0. 20 1,963 
ice i Role ae aera BAO) seca 0. 25 3,615 
Ge Siriaas Seay Ss SMO ae 0. 30 3, 920 
UL SOS SCTE gee, na ee BACOne ser 0. 35 2,006 
Sobers OEM Ee Se SACOgetece 0. 40 2,131 
1 a ee aie aa PAd Oe 0. 45 1, 862 
A Nae he aaa Sud One Sew. 0. 50 2,059 
: Effect on 
Effect on scales. crits 
Many alive ......-. No injury. 
MVdeadae ee: Do. 
SEA O eae ae Do. 
mT Olea Neis secs Do. 
aALey (Oa Sc Mkt toad ae Do. 
Sean Cl Oy et ewe ene Do. 
STEAK KO) on es Re Do. 
Seat O (Oy nen etc Do. 
FR SAIOKO) Sees ae eee Do. 
ere LOR pea ra ea nse Do. 
From the table it will be noted that all scales were killed without 
injury to the fruit, at all strengths except where 0.05 gram potassium 
cyanid per cubic foot was used. 
In this experiment (No. 1) at first 
