Effectiveness of the Nematicidal Preparation Against the Potato Nematode Complex

<i>Summary:</i> Potato cultivation is a crucial area in crop production, especially in the Southern Steppe of Ukraine, where agroecological conditions require effective plant protection strategies. Yield is influenced by numerous factors, one of which is infestation by phytonematodes. This is particularly relevant under irrigated farming conditions, which promote the development of harmful nematode species. The article presents the results of testing a nematicidal preparation based on the predatory fungus <i>Arthrobotrys oligospora</i> against a complex of potato nematodes under model vegetative experiment conditions. This approach makes it possible to evaluate the potential efficacy of the product before large-scale field application. A reduction was observed in the total number of phytophagous nematodes (<i>Paratylenchus nanus</i>, <i>Pratylenchus pratensis</i>), mycetophagous nematodes (<i>Aphelenchoides asterocaudatus</i>, <i>A. limberi</i>, <i>Aphelenchus avenae</i>), and saprophagous nematodes (<i>Aporcelaimellus obtusicaudatus</i>, <i>Chiloplacus symmetricus</i>, <i>Eucephalobus oxiuroides</i>, <i>Panagrolaimus rigidus</i>), as well as in the invasion intensity of dominant endophytic species. Double treatment (tuber soaking and vegetative spraying) resulted in the complete absence of <i>Pratylenchus pratensis</i> in tubers. The preparation did not significantly affect tuber yield structure, although a trend toward increased tuber weight was noted compared to the infected control. These findings are promising for the development of biological nematicidal control methods. The article presents the results of examining a nematicidal preparation based on the predatory fungus Arthrobotrys oligospora against a complex of potato nematodes under vegetation experiment conditions. The preparation reduced the overall nematode population and partially limited the activity of dominant endophytic species Pratylenchus pratensis and Paratylenchus nanus.