Soil nematode population studies of some selected plantation crops and uncultivated coastal thicket

Abstract

The study was conducted on citrus, plantain and pineapple plantations on the Teaching and Research Farm of the School of Agriculture, University of Cape Coast. The survey also covered undisturbed coastal thicket near the site of the study. The aim of the survey was to identify types and population levels of plant parasitic nematodes in soils of the different plantation crops and to find out whether the populations and nematode species differed from those in soils of undisturbed vegetation. The investigations were carried out from April to July 1993. Nematodes were extracted from 100 ml soil samples by an improvised Baerman’s Tray technique and the mean recorded. Nematode counts were determined from 1ml aliquots repeated tree times. Three genera, namely Rotylenchulus, Meloidogyne and Pratylenchus as endo-parasites, Tylenchus (semi-endoparasitic) and eight ecto-parasitics forms which included Xiphimena, a known virus vector, were identified. Meloidogyne, Pratylenchus, Helicotylenchus and Tylenchus occurred in all the plots studied. Hemicyclophora and Xiphimena were the least genera and occurred in low numbers. Plantain supported the greatest number of genera and also the highest nematode populations. There were positive correlations between crop types, soil pH, soil moisture and nematode numbers. Similarly, significant differences were observed between means of initial nematodes numbers at the beginning and end of the season.