The nematicide dodecan-1-ol has a reduced impact of on plant growth-promoting bacteria compared to conventional pesticides

Conventional pesticides commonly used in modern agriculture pose significant risks to plant health by disrupting soil microbiota, including beneficial plant growth-promoting bacteria. These non-target effects contribute to long-term soil degradation and ecological imbalances, ultimately undermining plant productivity and sustainability. Consequently, there is an urgent need to identify safer and more sustainable pest management alternatives that support plant health. Volatile phytochemicals, known for their bioactivity against plant pests, offer a promising solution due to their reduced environmental impact and lower toxicity.

This study evaluated the toxicity of dodecan-1-ol, a volatile compound with nematicidal properties, on crop-associated bacterial species of importance for plant growth and soil health: Bacillus megaterium, Pseudomonas azotoformans, Paenibacillus zeisoli, and Burkholderia phymatum. Direct-contact bioassays in 96-well microplates were used to monitor bacterial growth spectrophotometrically. For comparison, the conventional pesticides emamectin benzoate and oxamyl were tested under identical conditions.

Dodecan-1-ol inhibited bacterial growth by a maximum of 20%, significantly lower than the 93% and 11% inhibition observed with emamectin benzoate and oxamyl, respectively. These results were obtained at a concentration of 0.02 mg/mL for all compounds. Importantly, at this concentration, dodecan-1-ol achieves its lowest maximal effective concentration (EC₁₀₀) against plant-parasitic nematodes, whereas emamectin benzoate and oxamyl exhibit limited nematicidal efficacy and require substantially higher application rates in agricultural settings.

By combining effective nematicidal activity with minimal impact on plant-beneficial bacteria, this study highlights the potential of dodecan-1-ol to support plant health while addressing pest control needs. These findings emphasize its role as a safer and more sustainable alternative to conventional pesticides, with promising applications in integrated pest and soil management strategies to promote healthy crop growth and long-term agricultural sustainability.