Independent Study PROVES Bobbex Repels Deer
As noted on the table below, only a physical fence works better!


Chart showing Bobbex as most effective deer repellent (other than a fence)

As published in: Human Wildlife Interactions 4(1):56 66, Spring 2010
Effectiveness of deer repellents in Connecticut

Abstract: Browsing by overabundant herds of white-tailed deer can cause significant economic damage to agricultural crops and landscape plantings. In many instances, for both commercial growers and homeowners, commercially available repellents may be an appealing alternative to physical exclusion and lethal control of animals. We tested 10 different commercially-available repellents (Chew-Not, Deer Off, Deer-Away Big Game Repellent, Plantskydd, Bobbex, Liquid Fence, Deer Solution, Hinder, Repellex systemic tablets, and coyote urine) on yews (Taxus cuspidata Densiformis) at 2 different locations in Connecticut. The study included both positive (fence) and negative (no treatment) controls. We planted yews in 2 blocks at each location in the spring of 2006; each block had 12 groups of 6 yews. We randomly assigned one of the 12 treatments to each group of yews within each block. We applied repellents based on manufacturers label recommendations for the 2006 and 2007 growing seasons and recorded application costs. We derived a protection index based on plant size and dry needle weights at the end of the 2007 growing season.

Treatment effectiveness

Yew mortality averaged 7% and did not differ among repellents («2 11 = 10.1, P = 0.52). Size and needle weight did differ among treatments . Unprotected yews (negative control) were smaller than fenced yews (positive control) at Dawson. At Windsor, where browsing was minimal, plant size did not differ among deer repellent treatments. At Dawson where browsing was more severe, only yews treated with Hinder, Bobbex, and those protected by a fence were larger than unprotected controls (Table 3). Plants protected by a physical fence were 72% larger than unprotected controls. At Dawson, yews inside a fence had nearly 18x the needle-weights of yews that were unprotected from deer browsing (Table 3).
Yews treated with Deer-Away Big Game Repellent, Chew-Not, Liquid Fence, Hinder, and Bobbex also had greater needle weights than unprotected controls. Yews protected by Repellex, Deer Solution, coyote urine, Plantskydd, and Deer-Off were not larger than unprotected controls at both sites and did not have significantly more needles at Dawson. The effectiveness of the various repellents, as indicated by the Protection Index, varied widely among products (Table 3).

JEFFREY S. WARD, Department of Forestry and Horticulture, Connecticut Agricultural Experiment Station, P.O. Box 1106, 123 Huntington Street, New Haven, CT 06504-1106, USA jeffrey.ward@ct.gov

SCOTT C. WILLIAMS, Department of Forestry and Horticulture, Connecticut Agricultural Experiment Station, P.O. Box 1106, 123 Huntington Street, New Haven, CT 06504-1106, USA