For the second time this season we’ve asked four agronomists/advisors about the current issues of the season and the next management strategy to think about, with insights from Tessa Dimond (QLD), Fred Broughton (NSW), Mick Faulkner (SA) and Monica Field (WA).
Tessa Dimond, AGnVET Rural, St George, Queensland
Tessa Dimond said they’re experiencing a below average season for winter cropping and so they haven’t had the big disease events that were seen in the last few years.
“It’s been interesting because this time last year it was raining and then in a few months’ time we had flooding events and wheat that was under water and we couldn’t get on to harvest, so it’s a bit of a juxtaposition this year,” she said.
Tessa said even though they’ve had low disease risk so far with few fungicides going out, it’s still important they don’t become complacent.
“There are a lot of strategies to think about right now, but probably our main one is that we’ll still have rain events over summer this year, which is our predominant rainfall time. So we will have green bridges with volunteer cereals, chickpeas and pulses, so we’ve got to just make sure we keep on top of that so we don’t have disease coming from one season to the next.
“I suppose we’ve just got to ride this year out. It is a drier and hotter year than probably the last few years, but just remember to keep up the good agronomic practise to make sure we’re keeping everything clean and that we’re still a productive grains industry.”
Fred Broughton, Rural Management Strategies, Cootamundra, NSW
On the other hand, Fred Broughton says the season is going very well for the vast majority of growers in his region, with really good yield potentials, and the disease load hasn’t been too bad either.
“In the wheat crops, the majority of what we’re seeing is yellow leaf spot, septoria and very sporadic incursions of stripe rust. At this point in the barley, it’s mostly spot form net blotch and in the canola as yet, haven’t seen much sclerotinia or upper canopy black leg, but time will tell, I suppose,” he said.
“At this point, we’re at a bit of a knife edge at the moment, the crops are just coming to full flag, so it’s a very critical timing to be spraying at the moment. We’ll definitely be putting out more fungicide if they believe they’re going to be getting rain in the next few weeks.”
Fred said at the moment aphids have also been getting around, and so was something to keep in mind as the season starts to warm up, particularly if crops were stressed.
Mick Faulkner, Agrilink Agricultural Consultants, Penwortham, SA
Mick Faulkner said in his region everyone is on a bit of a knife’s edge, with substantially below average rainfall for nearly two months and a lot of nervousness around.
He said there are disease issues around, including low ascochyta blight levels in lentils and faba beans, some septoria tritici blotch in the lower canopy of wheat, isolated and severe reports of wheat powdery mildew, and some reports of stripe rust in the southeast.
“But speaking to a couple of consultants earlier, we were just realising that there was a lot more flutriafol used this year than perhaps we would have in the past because of that fear, especially of stripe rust, knowing that there was a green bridge over much of southern Australia,” Mick said.
“Barley’s unusual, in that I think this is probably our third year in a row that in a lot of the barley growing areas, the barley crops are remarkably clean, where we don’t quite expect them to be as clean as they are.
“There’s been a lot of protective sprays for sclerotinia, as I guess last year was probably South Australia’s more devastating year for sclerotinia than we’ve seen for a while, but this year, with the return of dry weather, the jury is still out, I think, on whether we’re going to get a response to those sprays.”
Monica Field, Farm and General, Esperance, WA
Monica Field said as people get ready for harvest, the season has been a mixed bag with the western side of Esperance a bit drier than the eastern side, and with that, lower than expected disease levels.
“I would say honestly, as a general comment, disease levels have been low this year, and I think that’s put down to weather. We’ve just had wet-dry-wet-dry, just depending where you are. And I think those weather parameters have played a pretty big part in where the disease levels are in your crop, essentially,” she said.
Monica said she’s seen some powdery mildew in the wheat crops, and barley disease levels of both net form and spot form have also been low, which could be due to the switch to more resistant varieties in the region.
“There’s definitely sclerotinia in canola, I don’t know that it’s developed as much as it could have if we’d had a wetter August,” she said.
“And then there’s a little bit of leaf rust kicking around in some wheat in the Mallee, which I guess is a little bit concerning because it’s probably not something we’ve seen develop much before, so that’s something that is a little bit different this year that we’re keeping an eye on.”
And the final word from CCDM
CCDM Director Mark Gibberd said as many regions watch the weather for the right timing for a final fungicide application, it’s important to make sure the return on investment is likely to be there.
“Every spray application has a potential to contribute to fungicide resistance across many of our pathosystems and, of course, fungicides are an expensive additive at this time of the year too,” he said.
“Support for these kinds of decisions in disease management is crucial. The reality is that we need much better disease models, we need much better sensing information, and we need to find better ways to utilise existing data sets from farmers in terms of paddock history and the potential for return on investment, in combination with within-season decision support.
“Those two things together that combine those data sets are going to lead to a much greater capacity to consider return on investment for fungicides at this time of the year and this year personifies exactly that kind of difficult decision making as to whether it is or isn’t worth putting out those late season fungicides.
“Through the global connections we’re generating, this is something that we intend to work on over the next couple of years.”
Liked this blog? Why not listen to the full interviews on the Crop Disease Podcast
