Toxicity of essential oils from Nordic plants against different pathogenic organisms and pests of cultivated plants

Abstract

Plant essential oils (EOs) represent a potentially effective, safe, and eco-friendly alternative to synthetic pesticides that cause negative effects for human health and the environment. While numerous studies have been conducted with EOs from tropical and temperate plants, very few studies have investigated the toxicity of EOs from Nordic plants against plant pathogenic organisms and pests. The present study evaluated in airtight glass chambers the toxicity of vapours produced by EOs obtained from sweet gale, balsam poplar, Labrador tea, jack pine, and black spruce against different pathogenic organisms and pests of cultivated plants. Vapours of Labrador tea EO strongly or completely inhibited the mycelial growth of Alternaria solani, Phytophthora capsici, and Sclerotinia sclerotiorum, while vapours of sweet gale, black spruce, and jack pine EOs inhibited the mycelial growth to a lesser extent. Vapours of all tested EOs were shown to have bactericidal activity against Clavibacter michiganensis subsp. michiganensis, insecticidal activity against bird cherry-oat aphids, acaricidal activity against spider mites, and phytotoxicity against Powell's amaranth. The study reveals the toxicity of EOs from Nordic plants against various pathogens and pests affecting crops, opening new avenues of research for the development of low-risk alternatives to synthetic pesticides in agriculture, with minimal impact on the environment and human health.