Distribution of plant-parasitic nematodes and comparative effects of fadama (hydromorphic) fields and upland fields on plant-parasitic nematodes and free-living nematodes on three indigenous vegetables commonly grown in Osun State Nigeria

Abstract

Surveys were conducted in 2016 and 2017 to investigate the distribution of plant-parasitic nematodes and the effects of fadama fields and upland fields on plant-parasitic and free-living nematodes. A total of 84 soil samples were collected from seven Local Government Areas visited in Osun State. Soil samples were collected from two fadama fields and two upland fields in all the LGAs visited. Nematodes were extracted, counted and identified under a compound microscope according to the morphological characteristics of the nematodes. The results showed that sixteen genera of plant-parasitic nematodes were found associated with Solanum macrocarpon, Amaranthus cruentus and Telfairia occidentalis. Meloidogyne\\ Helicotylenchus and Rotylenchulus were the most abundant nematodes associated with the vegetables. Fadama fields significantly had lower populations of plant-parasitic nematodes and higher populations of free-living nematodes in comparison with upland fields in fields sown to the vegetables. Farmers are advised to take full advantage of fadama fields in vegetable production.