Abstract: | Pratylenchus brachyurus is a phytonematode species mostly damaging crops. It is mainly controlled by agrochemicals which are harmful to the environment and public health. Such outcomes encourage the development of research on products and/or processes to control this phytonematode and to contribute to the sustainability of agricultural systems. Thus, the aim of the current study was to assess host suitability of Achillea millefolium to P. brachyurus, as well as the nematicidal potential of its essential oil and root exudates. We conducted two experiments with two different plant species—Glycine max (soya bean) and Achillea millefolium (yarrow)—based on a 2 × 3 factorial arrangement to assess host suitability. Plants were assessed 5, 10 and 15 days after inoculation through the fuchsine acid staining technique. Based on the results, A. millefolium was an unfavourable host to this phytonematode. Therefore, it can be recommended for crop rotation and/or succession systems in small areas. We tested the nematicidal activity of the essential oil and exudates of A. millefolium at concentrations of 0, 25, 50, 100, 200, 300, 400 and 500 µg/ml in a BOD incubator at 26°C for 48 hr. The essential oil showed increasing linear regression, that is the higher was the concentration, the higher was the mortality rate. Exudates showed a quadratic behaviour (p ≤ .05), leading to 60.83% nematode mortality. Therefore, the essential oil and root exudates of A. millefolium have the potential to control P. brachyurus. The essential oil showed antagonistic properties likely because of the presence of germacrene D (39.55%), (E,E)‐α‐farnesene (25.70%) and chamazulene (8.91%). |