Factors Affecting White-tailed Deer Browsing Rates on Early Growth Stages of Soybean Crops PDF Download

Author: Greg Colligan
Publisher: ProQuest
ISBN: 9780549387695
Category : Browsing (Animal behavior)
Languages : en
Pages :

Get Book Here

Book Description
Deer damage to soybean crops is a concern for soybean producers on the Delmarva Peninsula. Although researchers have documented decreases in the intensity of deer browse on soybean plants as the growing season progresses, an understanding of the mechanisms driving the decrease in deer browse is necessary for reduction and mitigation of deer damage to soybean crops. I tested 4 hypotheses to determine why deer browse rates decreases 3 weeks after plant emergence: plant phenology affects plant palatability, diet change occurs, deer damage induces a plant response making soybean leaves less palatable, and deer consume fewer leaves but the same amount of leaf biomass as the season progresses. I recorded deer browse in double and single crop soybean fields in Little Creek, Delaware during the 2005-2006 growing seasons. To test if plant phenology affected deer browse, I conducted a forage analysis of soybean leaves at different growth stages. Although forage quality components were variable across the growing season, white-tailed deer dietary requirements were met or exceeded in all cases expect one. I compared deer diet composition using microhistological analyses across the early soybean growing season. By late-May, crops constituted>76% of the items documented in deer diets. The proportion of soybeans in the diet increased from 13% to 37% from late-May to early-July. I tested for an induced plant response by comparing the browse rates of plots that were protected from deer browsing until 4 weeks after plant emergence to plots that received no protection and were browsed sometime in during the 1 st 4 weeks. Although I documented greater browse rates in the protected plots, I also documented that protected plots had taller plants suggesting that deer may have been attracted to the taller plants. The amount of soybean leaf biomass deer were consuming across the growing season was variable but did not decrease from the early to late growth stages of soybeans. Decreasing trends in deer browse, during the early part of the growing season, as reported by other authors were likely the result of how other authors determined browse rates. My research indicates that deer browse does not decrease 3 weeks after plant emergence. When browse rates are standardized by using consumed biomass per week, deer browse on soybean plants is continuous across the growing season. If deer continue to consume leaf biomass at a relatively constant rate as the plants grow more leaves, the impact on plant and the visibility of deer browsing to the agricultural producers will decrease across the season.