B OARD OF HORTICULTURE 121 



Keep Materials Moving. Stock materials in cartons, sacks or Containers 

 .should not be permitted to remain for indefinite periods in one place. Contami- 

 nation becomes general, and wliolesale destruction soon follows. 



Insect Proof Packages should be the aim. A product in cartons with an inner 

 sealed Container of waxed paper. if free from infestation wlien packed, is seldom 

 infested. 



Reprocessing. Materials such as prunes which are reprocessed at the time of 

 packinir. or any substance which can be subjected to heat (see below) for a brief 

 period will he free from active infestation when packed, and if in an insect proof 

 packa.iie or kept movinir, should remain free of contamination. Offen we have 

 observed a product, treated to free it of infestation. then packed for shipment and 

 stored for several days adjacent to bins of infested material. In such an event, 

 eggs will be liberally deposited on the package and where cracks or tears permit 

 entrance of the larvae, the infestation of the material is only a matter of time. 



Heat. A temperature of 125 to 130 degrees Fahrenheit will kill all stages of 

 stored product pests. where they are exposed to this temperature for one hour. 

 Small packages of infested material may be readily treated in a moderate oven. 

 For certain commercial products it would appear reasonable that heat could be 

 utilized as the medium of control, as is done for many of the large mills in the 

 Middle West. 



Fumigation 



Gas fumigation must still be the most general practice for the control of insect 

 pests of stored food products. The presence and possibilities of these pests are 

 so widespread it would appear advisable in contemplating the erection of ware- 

 houses, packing plants, etc., to consider gas-proof construction. At present in 

 Oregon it is the exception to find a building of this nature sufficiently well 

 constructed as to permit of effective gas fumigation. 



Carbon Bisulfide 



Carbon bisulfide is the most practical fumigant for the treatment of moderate 

 quantities of material. It can be used for the treatment of seeds intended for 

 planting, and foodstuffs are in no way injured when the gas is properly applied. 



This material is Inflammable, and some insurance companies may not insure 

 against fire where carbon bisulfide is being used for fumigation. 



Application. See that the room or Containers are tight enough to hold the gas. 

 The liquid carbon bisulfide may be obtained from any druggist, and six pounds 

 should be procured for eA'ery 1,000 cubic feet of space to be treated.* If the 

 temperature is low or if the gas can leak from the bin, a larger amount will be 

 necessary. Do not attempt to fumigate if the temperature is below 60 degrees 

 Fahrenheit. The gas is ineffective below this temperature. 



Carbon bisulfide is heavier than air and tends to settle. The liquid should be 

 placed in shallow paus on top of the material to be fumigated. Where considerable 

 surface is exposed it is well to divide the liquid and place in pans at several 

 Points, so as to obtain a more even distribution of the gas. As soon as the liquid 

 has been placed in position, immediately close the Container. Allow the gas to 

 act for from 24 to 36 hours. The bins or Containers may then be opened and 

 allowed to air out. 



Caution. Carbon bisulfide is very inflammable in both the liquid and gaseous 

 forms. Keep all lights, sparks or flames away from it. Do not use in a heated 

 room. 



•For smaller amounts of material the liquid should be used at the rate of two 

 ounces (about four tablespoonsful) for each bushel capacity of the Containers. 



