Use of Soap as a Repellent for Deer in 

 Apple Orchards 



James A. Parkhurst 



Department of Forestry and Wildlife Management, University of Mas- 

 sachusetts 



Browsing by white-tailed deer (Odocoileus vir- 

 ginianus) in apple orchards often causes tree defor- 

 mation, reduces anticipated fruit production, and in 

 recently established blocks, may prevent a grower 

 from realizing any economic return on investment 

 because of delays in producing the first crop. Many 

 methods to reduce impacts of deer browsing have 

 been tried over the years, each with varying success. 

 A technique that many claim to be economical and 

 that provides reasonable effectiveness is the use of 

 bar soap as a repellent. Researchers at The Con- 

 necticut Agricultural Experiment Station recently 

 studied the use of soap as a deer repellent by evalu- 

 ating the radius of effectiveness and examining 

 differences among brands [Swihart, R. K. and M. R. 

 Conover. 1990. Reducing deer damage to yews and 

 apple trees: Testing Big Game Repellent, Ro pel, and 

 soap as repellents Wildlife Society Bulletin 

 18(2): 156-62]. This article sum- 

 marizes their findings. 



Methods 



Researchers conducted tests 

 in 2 different orchards contain- 

 ing either all standard trees or a 

 combination of standard and 

 semi-dwarf trees during the 

 winter of 1988-89. Eight com- 

 mercially available brands of bar 

 soap (3.5-oz size) were used 

 (Table 1). Each bar of soap, with 

 its wrapper intact, was hung 

 from a lateral branch within the 

 browsing zone. Bars were spaced 

 a minimum of 25 yards apart 

 (within and between rows). Be- 

 cause investigators also wanted 

 to determine if visual cues, 

 rather than odors, were impor- 

 tant in providing repellency pro- 

 tection, they hung empty, 

 washed soap wrappers from 



trees in a fashion similar to the soap bars. The 

 effectiveness of soap and wrappers as repellents was 

 determined by measuring the amount of browsing 

 damage in December, just prior to the placement of 

 the test devices, and then again in February and 

 April after the devices were installed. Extent of 

 browsing impact was assessed by recording damage 

 to terminal shoots on 25 randomly selected twigs at 

 various distances (0-1, 1-2, 2-3, 4-6, and 9-11 yards) 

 from the hanging test devices. 



Results 



When compared with damage observed on un- 

 protected trees within the same block, browsing was 

 reduced 70% within 1 yard of a soap bar, whereas a 

 91% reduction was noted within 1 yard of an empty 

 soap wrapper. However, the mean percentage of 



Fruit Notes, Fall, 1990 



