Investigation of plant parasitic nematode species and population development in sunflower, wheat and corn production areas of Osmaniye province

In order to ascertain the nematode fauna and population densities in four distinct fields within the Toprakkale district of the Osmaniye province, a comprehensive survey was conducted, accompanied by the collection of monthly soil samples between the years 2021 and 2023. -The fields were cultivated with corn, wheat, sunflower, and soybean. In this study, the identification of saprophytic, plant-parasitic, and predatory nematode groups were identified . Among the plant-parasitic nematode groups, Rotylenchulus macrosomus and R. parvus were identified as particularly significant and prevalent. In the 2021-2022 period, the plant-parasitic nematode fauna exhibited the highest prevalence (60%) in the Kumluk land area and the lowest prevalence (42%) in the Göçmenler land area. The saprophyte rate was found to be at odds with this trend. Similar results were obtained in both 2022 and 2023, with an increase in the prevalence of plant-parasitic nematodes observed across all plots. The highest plant-parasitic nematode population was observed in corn plant of the Kumluk field in August, with a total of 2,010 individuals per 100 g soil, while the lowest population was recorded in the Göçmenler field in January, with a total of 920 individuals per 100 g soil. The highest population of saprophytic nematodes was observed in the Göçmenler field in August, with a count of 1110 individuals per 100 g soil. In contrast, the lowest population was recorded in the Kumluk field in September, with a count of 610 individuals per 100 g soil. The data obtained from this study indicate that the population densities of Rotylenchulus macrosomus and Rotylenchulus parvus were high in Kumluk field during two production seasons. In light of the population densities and population growth of both pests, it can be concluded that these species may have a detrimental impact on maize production. Consequently, it is recommended that the potential damage of these plant-parasitic nematodes be investigated in climate chambers and field conditions. Keywords: Fauna, saprophytic nematodes, cereals, Rotylenchulus macrosomus, R. parvus