FUMIGATION OF FRUIT TO DESTROY JAPANESE BEETLE 



25 



cellar for 5 days. Results of a t}^pical set of analyses are indicated 

 in table 5. 



Table 5. — Amounts of hydrocyanic acid, expressed as parts per million of fruit, 

 found in skin and pulp of bananas fumigated in a refrigerator car for 1 hour 

 with P/g pounds of hydrocyanic acid absorbed in wood-paper pulp 







Samples taken 





Samples taken 





Samples taken 



5 days after 





Samples taken 



5 days after 





within 2 hours 



fruit had been 





within 2 hours 



fruit had been 





of fumieation 



placed in cold 





of fumigation 



placed in cold 



Sample no. 





cellar 



.sample no. 





cellar 





Skin 



Pulp 



Skin 



Pulp 





Skin 



Pulp 



Skin 



Pulp 



1 



10 



2 











5--- 



10 



1 







1 



2 



5 



2 











6 



1 



1 











3 . 



4 

 5 



4 

 3 



1 

 1 





 





5 



1 

 1 















4 



8 













It can be seen from table 5 that 10 parts of hydrocyanic acid per 

 million was the greatest quantity found in any of the determinations. 

 Furthermore, 5 days after fumigation the hydrocyanic acid had dis- 

 appeared almost completely. 



INJURY TO FRUIT 



From the time bananas are picked and leave the plantations they 

 are subject to injury from bruising and scarring. Improperly 

 packed fruit, for example, may be tossed about on the boats or in 

 the cars. Fruit injured in this manner while green usually gives 

 little evidence of the injury until it has ripened, at which time the 

 skin darkens and the flesh just beneath becomes soft. 



Injury from hydrocyanic acid is very different, and there are 

 many factors which govern its occurrence and severity. It rarely 

 occurs with ventilated fruit. Even when iy 2 pounds of liquid 

 hydrocyanic acid was sprayed into the fruit compartment of the 

 car, no injury was detected. The situation is quite different with 

 refrigerated fruit, which becomes covered with condensed atmos- 

 pheric moisture as soon as it is brought from the hold of the ship 

 to the outside air. When calcium cyanide was dumped into the 

 ice compartments, as in the original fumigation procedure, particles 

 of the dust were caught by the moisture and reacted with it. Cer- 

 tain of the fruit company officials, however, claimed that the injury 

 which occurred was due to lime rather than the hydrocyanic acid, 

 since similar injury could be produced by dusting-^ fruit with hy- 

 drated lime. 



With the use of liquid hydrocyanic acid the possibility of lime 

 injury is eliminated. In this case any injury which results is un- 

 doubtedly caused by the absorption of the gas by the moisture on 

 the fruit. Very high concentrations or prolonged exposures cause 

 severe injury. Figure IT shows the differences in injury caused by 

 exposures of one-half hour and 4 hours to a concentration of 5 

 pounds of hydrocyanic acid per 1,000 cubic feet, the pictures having 

 been taken 5 days after the fumigation. 



Cyanide injury often starts as a slight discoloration at the point 

 of a bruise or a scar, but, unlike the latter, it spreads until a con- 



