'Dead heads': a durum danger signal
See p7 for latest research findings on the causes and cures of crown rot
Avoid growing highly susceptible durum where there has been evidence of crown rot in cereal crops. This is one piece of good advice from a recent Adviser Update series supported by growers through the GRDC in southern Australia.
Grant Hollaway of Agriculture Victoria says yield losses were as high as 20 per cent in 1999 in some Victorian paddocks although average losses were about 5 per cent.
"It is seen after flowering as scattered dead whiteheads in the crop and is controlled by lengthening the time between cereals in rotations and including non-hosts such as pulses or canola, or a grass-free fallow," he said.
Meanwhile, Hugh Wallwork of the SA Research and Development Institute (SARDI) has pointed to the link between crown rot and root lesion nematodes.
He says nematodes induce water stress in plants by attacking the root system; crown rot then builds up on plants growing under moisture stress.
"In situations where root lesion nematode populations are high, wheat varieties such as Krichauff, which are resistant to them, may appear to be more resistant to crown rot as well," he says. "However, under controlled test conditions for crown rot, most of the current wheat varieties appear to be equally susceptible."
Contact: Dr Grant Hollaway 03 5362 2111, Dr Hugh Wallwork 08 8303 9382