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trail builder than with the hand^baitirg program. Very conscientious employees are 

 necessary for hand-baiting as it is a tedious, and sometimes discouraging, job when 

 the mouse population in an orchard is small but still present. 



Apparently, there will be plenty of drop apples on the ground this year. If 

 this condition occuj-s in 2£ur orchard, our advice is that both Zinc-.phosphide-treated 

 oats and Zinc Phospldde-ti'eated apple cubes be Esed as a bait, acd it should be 

 heeded Field trials have indicated that even under normal conditions, the use of 

 this combination bait gives better pine mouse control. But when the orehard floor 

 is littered v;ith apples, the apple-and-oat partnership has a decided advantage. 



Mowing, as an indirect approach to mouse control, is frequently over-looked. 

 The goal here is a completely clean tree base, even if we cannot quite attain this 

 ideal \n.th mechanical equipment. It is surprising how much more grass can be dropped 

 by the cutter bar if you abandon the routine of mowing up and down the row in one 

 direction only, George Marshall of Fitchburg, Massachusetts, can t estif y to this. 

 After all, in a symmetrical orchard there are sixteen different directions to mow and 

 still be on a row of trees, provided ofcourse, that the orchard floor is smooth enough 

 to allow traversing on other than the spray rig path. 



Special emphasis should be placed on late season mov/ing this year. Dry weather 

 persisted well into August bvit then the tropical cloudbursts came^ As in the tropics, 

 the grass cover has sprouted into a luxuriant jungle - an ideal home for the infamous 

 orchard mice. Removal of this cover before baiting time will be of great value, 



—W.R.Jones 



Mouse Popul at ions 



According to an article by G, C, Oderkirk, the mouse population 

 varies markedly from year to year^ The reason for this fluctuation has 

 not beer/dbfinitely established, although adverse weather conditions and 

 disease are considered important factors. Meadow mice are prolific and 

 under favorable conditions, have from 5-10 litters of yoiing a year, with 

 any\?here from 1-11 per litter. The number and size of litters are usu- 

 ally greater in the so-called "mouse years". During these years, the 

 mouse population increases rapidly and if conditions are favorable, 

 they increase over a period of k-6 years and then become scarce. These 

 population peaks are reached about every four or five years, 



"It woxOd be nice if we could predict the 'mouse years' but they 

 are somewhat localized. However^, knowing that these fluctuations occur 

 makes it important for the fruit grovrer to keep an eye on the ground to 

 note the runways and other indications of mouse abundance," 



ED. 



from inSCONSIN HORTICULTURE 



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Publication approved by George S, Cronin, State Purchasing Agent 



#19 



