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RODENT CONTROL _IN STORAGE AND ORCHARD * 



(F. B. Schuler of the Fish and Wildlife Service offers thosa timely- 

 suggestions on the prevention of rodent damage.) 



Fruit growers should be aware of the possible doaage to stored fruit 

 by rats and mice. Every fall there are reports of excessive damage to fruit 

 hold in cormnon and cold storage. On many farms the reported loss is as high 

 as ton bushels for every thousand stored. This loss can be prevented, 



Coinmon Storage. Conmon Storage is nore open to attack by rodents than fruit 

 held in cold storage, since the former is usually an open building used 

 temporarily for holding the surplus crop. The following recomHondations are 

 made for a rodent-free storage; 1, Remove all trash from the building sind 

 the vicinity of the proposed storage area, 2, Stack usable lumber at least 

 one foot above the ground level, 3, Bum the waste accumulated from this 

 operation. Since rats and mice are Vary animals, the lack of shelter or con- 

 cealment discourages their presence. Therefore, plug with concrete, or shield 

 with galvanized sheet metal or 4 x 4 hardware cloth all openings in foundation 

 walls, floor or embanlanents. Where a rat colony already exists, extermination 

 must take place before harvest. Write to your County Agricultural Agent 

 for information on control methods. 



When the fruit is harvested it should be stacked at least six 

 inches from the walls, on wooden slate at least two inches above the floor. 

 This will allow for proper ventilation and is also of assistance in controlling 

 the rats and mice. The area along the walls and the free space under the 

 boxes can then be utilized for the distribution of strychnine-treated steam- 

 crushed oats. The oats should be scattered in tablespoonful amounts in theso 

 areas as the storage room is being filled. Bait stations made from mailing 

 tubes, hollow tile, rolled tarpaper or similar devices should be inserted 

 throughout the stacked boxes above ground level, A tablespoonful of the 

 treated grain in each station will be adequate. 



Cold Storage. The rodent problem in cold storage usually results from the 

 mice being carried into the storage with the fruit. Whenever practicable 

 the fruit should bo moved into the storage the some day it is picked. If 

 allowed to stand in the orchard during the night, mice will use the boxes for 

 shelter and be carried into the storage. Occasionally a cold storage is 

 found that is not mouse proof. Check all drains and vents to be sure they 

 are screened. Hardware cloth with four wires to the inch should be used to 

 mouse proof these openings. In s ;me cases pipe inlets, electrical conduits, 

 offer an indirect mearxs of entrance to the storage. Where they are accessible 

 to the mice they should be checked to see that the exteri ^r of the building 

 is tight. The distribution and placement of strychnine-treated oats should 

 be followed as outlined above. The important thing is to expose the bait 

 while filling the storage. The strychnine-troated steam-crushed oats may 

 be procured through your County Agricultural Agent. 



Orchard Practices . Fruit trees are girdled in all months of the year. The 

 practice of keeping tree bases free of yegetation is a v/orthwhile precaution- 

 ary measure. Removal of the s )d ar:Jund the tree bases reduces the mouse 



