Evaluation of Selected White-tailed Deer Repellents on Sweetpotato

Abstract

<jats:p>With an estimated white-tailed deer population of &gt;25 million in the United States and 1.7 million in Alabama, deer feeding damage has become a serious problem for vegetable growers. Typically, deer feed on foliage during plant growth or dig roots near harvest time. Because there is currently no method available to control deer feeding damage to sweetpotatoes, studies were conducted with both confined and free-ranging white-tailed deer to determine the effectiveness of several commercial deer-repellent products on `Beauregard' sweetpotato. In 1998, testing was conducted at the Alabama Agricultural Piedmont Substation in Camp Hill, Ala., with free-ranging deer. Treatments included Deer Away (egg-based spray and powder), Tree Guard, Garlic Barrier, Thiram (a commercial fungicide), as well as a nontreated control. Damage was rated on a 0 to 4 scale (0 = no damage; 4 = 100% damage). In 1999, testing was continued with confined deer at the Auburn Univ. Deer Research Facility in Auburn, Ala. Havahart egg-based spray, Hinder, Grant's, XP-20 (Thiram), and Ro-Pel were applied to potted `Beauregard' plants. Nontreated plants were also included. Pots were placed in 2 one-acre pens, each containing six adult deer. Damage was rated on a 0 to 3 scale (0 = no damage; 3 = plant eaten to pot line or uprooted). Significant (<jats:italic>P</jats:italic> &lt; 0.05) differences were found among products. The most effective products in 1998 were Deer Away powder, Garlic Barrier at 3× the manufacturer's recommended rate, and Deer Away spray. In 1999, Havahart egg spray provided the highest level of protection, followed by XP-20. Although no product provided complete protection to sweetpotato, egg- and Thiram-based products were most effective in 2 years of testing. None of these products are labeled for use on food crops at this time.</jats:p>