Soil nematode communities associated with hazelnut orchards in Turkey

The study was conducted to investigate the status of soil nematode communities in hazelnut orchards in Ordu province, Turkey. Nematodes were identified to genus level and allocated to trophic groups. A total of 50 taxa were found from hazelnut growing areas including 19 plant parasites, 12 bacterivorous, 4 fungivorous, 4 predators and 11 omnivorous. Genera Tylenchus (94.5%), Gracilacus (79.1%) and Helicotylenchus (56.4%) as plant parasites, Acrobeloides (68%) as bacterivores and Aphelenchoides (68.2%) as fungivorous were widespread and found in all districts. The highest abundance of plant parasites was in Kabatas (277 individual/ 100 cm3 soil) followed by Golkoy (196.6 ind./ 100 cm3 soil) district. Criconemella, Meloidogyne, Paratylenchus and Pratylenchus were found as important genera by means of the damage potantial on hazelnut as plant parasitic group. The other trophic groups were at desirable level for an healthy soil system. Key words: Hazelnut orchards, hazelnut nematodes, nematode community, nematode abundance, Ordu.