Effectiveness of Diesel as a Mammal Repellent for Direct Seeding of Acorns

Abstract

Abstract:The assisted regeneration of oaks can be achieved through seeding or planting. Whereas direct seeding of acorns has several advantages over planting nursery-grown seedlings, the problem of seed predation by mammals precludes its widespread application. We investigated the potential of diesel as a mammal repellent to prevent the consumption of Holm oak acorns. We tested the effect of submerging acorns in diesel for 0, 6, 12, and 24 h on acorn predation in a field experiment in the Sierra Nevada Natural Park (Granada province, Spain), and the potential effect of the same treatments on seedling emergence and growth in a nursery experiment. The field experiment showed no reduction in acorn predation through diesel. On the other hand, submersion in diesel hindered the germination of one in every four sown acorns regardless of submersion time. Our results are in line with many failed attempts to protect acorns with chemical repellents and suggest that an effective, universally-abundant, inexpensive, and easy-to-apply acorn protector to enhance the success of seeding operations is yet to be found.

The effects of four repellents on bank vole consumption and germination of beech nuts and acorns

“…Previously, several techniques have been implemented to reduce negative effects of rodent seed predation. This include the use of rodenticides (Myllymäki 1975) which for environmental and regulatory reasons often is no longer allowed, mechanical site preparation of restoration areas (Löf and Birkedal 2009), and diesel submersion of seeds as a chemical repellent (Bäumler et al 1990;Leverkus et al 2017). Other methods for example are spreading of sunflower seeds and oats mixed with seeds of Douglas fir (Pseudotsuga menziessi (Mirb.)…”

“…Citronella oil is another plant-based substance that has been used as an insect repellent (Biswas and Biswas 2006). Only a few studies have, however, addressed the use of such chemical repellents in order to deter rodents from seed consumption of European broadleaved trees (Bäumler et al 1990;Willoughby et al 2011;Leverkus et al 2013;Sunyer et al 2013;Leverkus et al 2017).…”