Biological suppression of root-lesion nematodes in grain-growing soils

Abstract

Root-lesion nematodes (RLNs) are found on 75% of grain farms in southern Queensland (QLD) and northern New South Wales (NSW) and are significant pests. This project confirmed that biological suppression of RLNs occurs in soils, examined what organisms are involved and how growers might enhance suppressiveness of soils. Field trials, and glasshouse and laboratory bioassays of soils from fields with contrasting management practices, showed suppressiveness is favoured with less tillage, more stubble and continuous intensive cropping, particularly in the top 15cm of soil. Through extensive surveys key organisms, Pasteuria bacteria, nematode-trapping fungi and predatory nematodes were isolated and identified as being present.