WHITE-TAILED DEER PREFERENCE OF CORN HYBRIDS DURING THE GROWING SEASON.

Joshua A. Delger, Department of Wildlife and Fisheries Sciences, South Dakota State University, Brookings, SD 57007

Field corn (Zea mays) damage by deer can be substantial and result in millions of lost revenue.  Numerous methods exist to aid in minimizing deer depredation on corn, but all have met with varying degrees of success and feasibility.  In addition, no information is available on preference of white-tailed deer (Odocoileus virginianus) for corn hybrids during the growing season and how preference might affect depredation patterns.  The objectives of our study were to 1) document deer preference among corn hybrids and husbandry practices during the growing season, 2) examine physical and nutritional characteristics that make hybrids more or less desirable to deer, and 3) compare preference of captive and wild deer through the use of manipulated food plots in rural areas.  Research was conducted at the South Dakota State University, Wildlife and Fisheries Research facility in Brookings, South Dakota.  Captive adult female white-tailed deer (n=4) were used in corn food plot studies with different corn hybrids planted in subplots separated by grass buffers.  Preference was documented by consumption of each hybrid during timed trials.  In 2006, data were collected weekly from 05 June – 15 September.  Preference differed (P<0.02) among hybrids throughout the study period.  Mean weekly number of feeding observations for hybrid A (Dekalb DKC44-92 (RR2)), hybrid B (Dekalb DKC46-28 (RR2)), and hybrid C (Dekalb DKC48-52 (RR2)) were 48.2, 33.4, and 34.5, respectively.  In 2007, data were collected weekly from 27 May – 29 August.  Preference differed (P<0.001) among hybrids within each growth phase (early growth, rapid growth, dry-down) throughout the study period.  Mean weekly number of feeding observations during early growth was 50.8 for hybrid A, 32.5 for hybrid D (Dekalb DKC40-07 (RR2)), and 42 for hybrid E (Dekalb DKC55-82 (RR2)); rapid growth weekly observations were 44 for hybrid A, 67.7 for hybrid D, and 50 for hybrid E; and dry-down weekly observations were 40 for hybrid A, 22 for hybrid D, and 31.7 for hybrid E.  Experimental food plots also were established in cooperation with local landowners in areas susceptible to depredation by wild deer.  Preference was documented by the frequency of damage within each plot.  Preference differed (P=0.06) among hybrids with mean percentages of plot damage at 48% for hybrid A, 29% for hybrid D, and 23% for hybrid E.  Use of certain corn hybrids and/or husbandry practices (e.g., herbicide, fertilizer treatments, etc.) could reduce deer depredation by altering (either increasing or decreasing) use of corn depending on management prescription.  Results of this study will provide recommendations for minimizing crop damage experienced by crop producers and maximizing the effectiveness of state managed food plots.