Root lesion nematodes (RLN) are microscopic, worm-like organisms that feed within and damage plant roots, thus reducing crop yield. The key to managing RLNs is to identify  paddocks with yield-limiting numbers present, then incorporate resistant crops and varieties into rotations to reduce their number.

Key Points

• Root lesion nematodes are species of Pratylenchus that feed on the roots of crops and can cause yield loss
• The yield loss caused by RLN is related to their number in the soil at planting
• Losses are more likely to occur when September and October maximum daily temperatures are above average and moisture is limited
• RLN have a wide host range and can multiply on cereals, oilseeds, pulses and pastures as well as on broadleaf and grass weeds
• The main RLN species in the southern region are Pratylenchus neglectus and P. thornei
• When RLN species are present in a paddock, this affects management practices, particularly the selection of rotational crops. This is because crops and varieties can vary in their resistance or susceptibility to each nematode species
• A PREDICTA® B test conducted prior to sowing can identify the number and species of nematodes present in the soil and thereby inform management practices
• Crop rotations using resistant crops/varieties are ecommended to reduce RLN population densities and minimise yield losses in subsequent crops.