January 15, 2012
Winter crop growers are being advised to take immediate steps to prevent significant yield losses caused by root lesion nematodes, which are microscopic worms that live inside the roots of crops.
NSW Department of Primary Industries (NSW DPI) Tamworth based plant pathologist, Steven Simpfendorfer, said yield losses of up to 35% were recorded in nematode intolerant winter crop varieties in 2011.
“A random paddock survey in northern and central NSW last year, funded by the Grains Research and Development Corporation, revealed that 82% of surveyed cropping paddocks had root lesion nematodes,” he said.
“In some districts these nematodes were detected in all paddocks sampled.
“Populations in some paddocks were 25 times the critical threshold where significant yield loss occurs in intolerant varieties.
“These results suggest that many growers are losing significant crop yield in their farming system and may be confusing nematodes with other causes of poor crop performance.”
NSW DPI Dubbo district agronomist, Kathi Hertel, said most growers need to find out if nematodes are present in their paddocks before selecting crop varieties.
“Soil tests should be conducted to test for the presence of nematodes, to identify which species are present and in what populations,” she said.
“With this soil test information, growers should choose crops and varieties that will reduce or maintain root lesion nematode numbers to less than 2000 per kilogram of soil.”
NSW DPI has produced a series of video clips to help growers better understand root lesion nematodes that can be viewed at http://www.dpi.nsw.gov.au/videos/nematodes
“One clip provides an understanding of the hidden problem of root lesion nematodes and another examines their impact and management through a case study,” Ms Hertel said.
“Steven Simpfendorfer also presents a three part series explaining what root lesion nematodes are, where they are found, why they matter and what growers can do.”