Abstract

Quantification of root lesion nematodes (Pratylenchus thornei and P. neglectus) was evaluated using three different methods; the Whitehead tray method, the mister method and the commercially available quantitative DNA assay. These methods were compared to determine the effect of soil water content, sampling method and soil storage conditions on estimates of pre-sowing densities of nematodes. The Whitehead tray method, which is reliant on extraction of live nematodes, recovered fewer nematodes from dry soil than from moist soil and fewer from soil dried before storage. By contrast, the DNA assay was not influenced by soil water content at the time of sampling or drying of the soil after sampling.