Testing Seasonal Disparity as a Determinant of Phyto-Parasitic Nematode Dynamics in an Agroecosystem

Abstract

Soil inhabiting organisms, including phyto-parasitic nematodes are highly sensitive to abiotic stimuli impacting the conduciveness of the soil ecosystem. Stimuli such as seasonal disparities may favour nematode survival at one point, and pose survival threat at some other point and vice versa. Therefore, this study tested the effects of seasonal disparity as a critical driver of phyto-parasitic nematode dynamics in an Agroecosystem. Soil samples were collected using a modified soil auger and nematode extraction was carried out using the modified Bearman’s technique. Result shows higher occurrence of phyto-parasitic nematodes at wet season when compare with the prevalence during the dry season. However, vertical distribution of nematodes saw higher populations at 16-30 cm core depth when compare with distribution at 0-15 cm depth at dry season. However, results on the vertical distribution of nematodes during the wet season was contrary as seen in dry season. The study revealed that nematode dynamics and species distribution across core depth are influenced by edaphic parameters, which are directly regulated by seasonal disparity. The study established that disparity in season constitute a significant force predicting nematode dynamics in agroecosystems. Wet season raises survival chances of juvenile, ensure adequate water content in soil and increases nematode populations. The dry season post some level of stress on phyto-parasitic nematodes, which could restrain motility, compel down ward migration, prompt anhydrobiosis and intensifies root tissue penetration. Seasonal disparity can prompt a shift in microbial associations to the survival advantage of certain species of phyto-parasitic nematodes and inhibits the populations of other species in the ecosystem.