Community Structure of Soil Nematodes Associated with Solanum Tuberosum

The soil nematode food web structure under a potato crop compared to a forest control treatment was investigated for 10 months. All nematode functional guilds were recovered from both treatments. Higher populations of enrichment nematodes (bacterivores and fungivores) were recovered in the potato plots and this is attributed to possible higher amounts of organic matter in the crop plots as compared to the forest control. For the pest suppression species, higher populations of carnivorous nematodes were recorded in the forest samples, while higher populations of the omnivorous nematodes were recorded in the potato plots. It will therefore seem that while the environmental response of predatory (carnivorous) nematodes is linked to physical perturbation, food sources are a more important factor in the environmental response of the omnivorous nematodes. Whereas the plant-feeding species of the Pl3 class were significantly higher in the crop plots, the Pl5 plant species were significantly higher in the forest control samples. These differences are attributed to host specificity. Overall, the plant-feeding nematodes dominated (9 families, 14 genera, 35.73 % total biomass contribution), followed by the enrichment nematodes (8 families, 12 genera, 33.53% total biomass), and then the pest suppression species (9 families, 19 genera, 30.76% total biomass). Based on these results plant-parasitic nematodes of the Pl3 cp class particularly Helicotylenchus mucronatus, Rotylenchus buxophilus, and Meloidogyne microcephala, are considered a potential threat to potato production in the study area.