Deer are the leading cause of crop damage by wildlife in Delaware. In neighboring Maryland, the government estimates showing approximately $10 million in losses annually, with 77% of those losses attributable to deer (USDA NASS 2011). Delaware faces greater challenges than many other soybean growing areas in the country due to smaller field sizes that are more often interspersed with and bordered by forested areas that provide refuge for deer, which emerge to graze highly palatable and nutritious soybeans. Farmers have regularly identified deer and wildlife damage as one of their top concerns, and frustrations by farmers are well documented in news media articles. Soybean yields in 2020 in certain fields at the Wye Research & Education Center in Queenstown, MD, were reduced by 20-30 bushels per acre in a field bordering a forested area. At a farm outside of Harrington, DE, yields were reduced by 66%. While hunting and crop damage permits allow some farmers to reduce deer population densities, some locations are not amenable to this due to factors such as landowners or neighbors that do not allow hunting, restrictions on method and time of take with damage permits, nocturnal grazing activity, and time required to harvest sufficient numbers of deer.

We seek to test the effectiveness of three deer repellent options on a 35-acre farm outside of Harrington, DE.

The project will be implemented as an exploratory case study at the Streett Farm outside of Harrington, DE. We will spray approximately ¼ of the field with each of three sprays and leave ¼ of the field as a control. We have researched as affordable options with pricing under $15/acre of raw materials for 4 spray applications over the growing season approximately every 2 weeks, Hinder, DES-X, and Plantskydd.

We will break the field into 3 sections to test each of the repellents (example fig. 1), and will leave an area of the field unsprayed as a control. We will place one to two 10’ diameter hogwire deer enclosure on each plot and control to assess yield potential and plant production in the absence of grazing.

Updated December 19, 2023:
Fields were sprayed 3 times with 3 different chemicals. Soybeans looked remarkable. Grazing exclosure data were cut and measured.

Updated December 19, 2023:
Initial results have been incorporated into Agronomy Day presentations given to over 230 people in Maryland. we are attempting to access precision agriculture data to better assess repellent efficacy and differneces between treatments. At first glance, they all seem to have worked quite effectively.