West Prairie grain producers Roger and Lisa Gwynne have hosted trials and field days for more than 40 years. Roger says his father Alex worked closely on nematode research over many years with Queensland Department of Primary Industries officer Nev Douglas, followed by Professor John Thompson, a former government soil biologist and now a University of Southern Queensland emeritus professor.
A part of the huge Jondaryan pastoral station until it was carved off in the 1940s, Roger says their farm, Tangalooma, was on a treeless plain, featured good black cracking clay vertosol soils and grew beautiful crops.
“When we still had cattle on the place, we were growing oats for fodder and seed, and the oats performed fine,” he says. “But an issue developed where we couldn’t grow good wheat crops. In the early years you’d often have an odd plant here and there that looked better, but they didn’t know what the problem was. It took the researchers to discover it was nematodes.”
Long-term trials at Tangalooma have found nematodes caused wheat yield loss in nine years out of 10, and slashed up to 50 per cent of the yield potential from intolerant varieties.
Roger says he has learned a lot from hosting the trials, including the importance of rotating out of wheat and choosing less- susceptible varieties, such as LRPB Reliant and Sunmaster. “We don’t grow a lot of wheat – we’re mainly summer cropping – so it can be many years between wheat crops but that doesn’t mean you eliminate nematodes because they persist in the soil,” he says.
The trials are helpful for giving us insight into new varieties that are coming along, especially those that are tolerant to disease, and rotations.
Roger, wife Lisa and their son Brady produce mostly summer crops of sorghum, corn and cotton, with winter crops of wheat, barley and chickpeas when conditions suit.
They have grown mungbeans in the past; Roger says he had not noticed any impacts from nematodes but that does not mean they were not affected.
Preparation of the trial sites begins with a summer crop – usually sorghum – then long fallow, wheat, and the researchers plant and manage their trials in the following year.
There are four plots totalling about 15ha which cycle through that process.
More information: Testing for nematodes just as important as nutrients