FRUIT NOTES 

 October 19$$ 



CONTROL OF RODENTS IN APPLE COID STORAGES 



Apple cold storage rooms on the farm are becoming a common sight o One of the 

 problems with which a storage operator may have to contend is a rodent infestation 

 in the storage after the room is partially or completely filled, ilost storages 

 are inherently roden-proof . Before starting operations each season access points, 

 such as the openings around pipes, and places that offer rodent harborage, such as 

 breaks in the insulation, shovQd be checked and repaired if necessary* The areas 

 around doors and loading ports should be free of debris in which rats and house 

 mice imy lurk, seemingly waiting for an opportunity to dash into the storage proper. 



The major source of infestation in apple storages is those rodents, chiefly 

 meadow and deer mice, that will be brought into the storage in boxes of apples. 

 MeadoviT mice are apt to enter at any time boxed appled remaining undisturbed in the 

 orchard. Deer mice like to make nests in those filled boxes that remain in the 

 orchard overnight. Transportation of loaded boxes to the storage as soon as 

 practical is the ansvjer here, of course. 



These suggested practices greatly reduce the danger of rodent infestation in 

 a storage but many times mice will be found in a storage regardless of the care 

 exercised to prevent it^ The control irethods remaining are the use of poison 

 baits and gassing. 



Strychnine-treated Steam Crushed Oats is the recommended bait for mouse control 

 in storagesT This material remains toxic longest under the humid conditions of the 

 storage room. Teaspoonful quantities of the poisoned oats are p]aced at intervals 

 along the walls, in alleys, or under pallets, Ihe limited range or travel of these 

 mice must be recogjaized. Every mouse should be able to find at least one bait 

 within the circumference of its movements. Obviously this type of baiting must be 

 done progressively as the storage is fillede 



Gassing of an apple cold storage is an absolute control of all rodent species. 

 Gassing with any material must be carefully done to prevent damage to fruit or in- 

 jury to operator. Some additional equipment or minor alterations in construction 

 may be necessary. For these reasons the services of a commercial extenninator 

 should be considered. 



The gassing of a storage demands that the room to be treated be reasonably 

 gas-tight. Door and port gasket seals can be insured by applying a layer of 

 vaseline where necessary. The use of ona of two materials ia recommended? (a) 

 Methyl Bromide!/ j or (b) Carbon lioxidei/. Methyl Bromide should be used two or 

 three weeks after apples cease to be brought in. This delay is desirable in 

 order that the chemical will have no effect on the ripening of the fruit. Treat- 

 ment with Carbon Dioxide has been found to be most effective immediately after 

 loading ceases. Gassing with either should be made during humid, above-freezing 

 weather so that proper ventilation can be secured afterward without injury to fruit. 



