The Kolliases raise Fraser fir and other species for sale as Christmas trees. Fraser fir are particularly suitable for this use because of their soft and aromatic needles; they are also, however, favored by deer for browsing. Mr. and Mrs. Kollias used their SARE grant to compare several different sorts of deer repellants on their trees.
They marked out five blocks on their farm, each holding two hundred four-year-old Fraser fir trees. One block was kept as an untreated control, and the other blocks were treated with 1) Thiram, 2) Deer-away, 3) Dial soap, and 4) cougar urine. The first two are commercial deer repellants; the latter two are widely reputed to serve this function as well. The treatments were applied in September of 1995, and the effects assessed the following spring.
Mrs. Kollias says the plots treated with Thiram and Deer-away suffered as much damage as the control plot. She consequently concludes that these commercial preparations are ineffectual. The plot treated with Dial soap suffered severe damage, but from other causes than deer. Mrs. Kollias is not sure what caused the damage sustained by the trees in this plot. It may have been snowmobilers; in any case she feel that the question of the efficacy of Dial soap as a deer repellant remains unanswered. She says the plot that was treated with cougar urine clearly sustained less damage than the control.