24 



FUMIGATION OF APPLES FOR SAN JOSE SCALE. 



As shown above, all lots of fruit of this variety from the western 

 New York orchard were injured by fumigation. The injury increased 

 in extent along with the increase in period of exposure. A stronger 

 dose for a shorter period of exposure was less injurious than a weaker 

 one for a longer period, as seen by comparison of Nos. 54 and 59. 

 It will also be noted from Nos. 44, 44a, and 44b that injury does not 

 depend upon whether the fruit be dry, wet, or moist at time of treat- 

 ment. The injury, in fact, was less pronounced on the moist and 

 wet samples than on the dry fruit. The increased injury noted at 

 time of second examination of Nos. 52 to 59 was undoubtedly due in 

 part to the appearance of the so-called " cold-storage scald," to which 

 this variety is quite susceptible, as shown by the untreated fruit kept 

 for comparison. With Nos. 44, 44a, and 44b, the examinations were 

 made too long after treatment to avoid danger of confusion of cold- 

 storage scald, though it may be said that gas injury was noted soon 

 after treatment. 



As bearing on the possible influence of moderate or excessive 

 moisture on fruit at time of fumigation, the following tests are 

 brought together, in part from other tables, and some are not else- 

 where presented: 



Table VIII. — Effect of fumigation with hydrocyanic-acid gas on fruit in a dry, moist, 



and wet condition. 



Experi- 

 ment Variety of apple. 

 No.— i 



40. 



44a.. 

 44b.. 



28 1 Baldwin. 



30 do... 



York Imperial . . 



....do.. 



Rhode Island 

 Greening. 



....do 



....do 



.do. 



.do. 

 .do. 



.do. 



Kind of package and con- 

 dition of fruit. 



^ bu. basket; fruit dry. 

 I bu. basket; fruit wet. 

 § bu. basket; fruit dry. 



J bu. basket; fruit moist, 

 i bu. basket; fruit wet. . 



Barrel; fruit wet 



Barrel; fruit moist 



....do 



...do 



....do 



do 



Rate at 



' 1 



which po- 



Length ! 



tassium 



of ex- : 



cvanid was 



posure. 



used. 





Gr.per cu.ft. 



Hours. 



1.5 



1 



1.5 



1 



0.30 



1 



0.30 



1 



0.30 



1 



0.30 



1 



0.30 



1 



0.30 



1 



0.30 



1 



0.30 



1 



0.30 



1 



Effect on 

 scales. 



No record — 



do 



All dead 



do 



do 



One doubtful 

 All dead 



do 



do 



do 



do 



Effect on 

 fruit. 



No injury. 



Do. 

 Badly in- 

 jured. 



Do. 



Do. 

 No injury. 



Do. 



Do. 



Do. 



Do. 



Do. 



COLD-STORAGE SERIES. 



In order to test the fumigation process upon a larger scale, approxi- 

 mating what might obtain in commercial practice, a larger fumi- 

 gatorium was constructed, 6 by 6 by 8 feet. The sides, ends, and 

 top were made separately, using 2-inch square lumber for the frame- 

 work. These frames were covered with 10-ounce duck, which was 

 treated with two coats of boiled linseed oil. Previous to bolting the 

 frames together, strips of heavy felt cloth were glued where the 

 frames came in contact, giving a very tight union. On the floor, a 



