For the second time this season we’ve asked three agronomists about the current issues of the season and the next management strategy to think about, with insights from Rohan Brill (NSW), Jana Freebairn (SA) and James Bee (WA).
Prefer to listen to the interviews in full instead? Press play below, otherwise keep on reading!
James Bee, Elders, Albany, WA
James Bee said the increase in rainfall has given growers in his region more confidence in the season, where he’s expecting many are aiming for an average one. Also, disease pressure has been quite low.
“So it’s all holding quite well at the moment. But again, we haven’t had conditions that are super conducive to disease progression. It has been quite warm combined with not a lot of rainfall, so not really as humid and wet as we’d normally see,” he said.
James had observed some wheat powdery mildew in Scepter wheat last week, saying now is a good time to look down low in the canopy and have a think about the varietal susceptibility and whether it needs to be controlled or not.
He said there has been a lot of reports of aphids and other insects such as diamond back moth affecting canola, so he suggested growers get in touch with their retailer and make sure they have secured their chemical requirements.
“Because it’s hard to forecast for the seasons, especially if it’s a roller coaster one like this year,” he said.
“So I’d probably just suggest if they require it, then they should have a chat to the people they deal with to make sure that they’re organised for the rest of the season because if we continue getting late rain, it means our yield potential could be really good.
“Rain at the end of the year is much better than rain at the start of the year to maximise yield potential, so if we can crack a soft off finish, I think everyone will be very happy and, in that case, we need to protect that yield potential.”
Jana Freebairn, Pinion Advisory and WeedSmart, Freeling, SA
Jana said the season has been a tricky one, with the region not yet reaching Decile 1 rainfall for the year, with temperatures well about average and windy conditions. Even so, the crops in the Lower North look okay.
“It’s amazing how they look considering when you look at the rainfall numbers,” she said.
“We’ve been on a knife edge for the last month, really. We’ve sort of said, if we just get a bit of rain now we might still be able to get close to average yields. But we’ve been saying that for a while. So, yeah, we’re draining the bucket in terms of moisture.”
Jana said she was very surprised to find stripe rust in Calibre and Sheriff CL Plus wheat last week in the Lower North, and since then hearing about a few other reports of stripe rust from around South Australia too.
“And that was on an unprotected crop. So that hadn’t had any fungicide or flutriafol on the seeding fertiliser. On paddocks that have had flutriafol, I can’t find it. So that’s obviously still offering some protection.”
She said the main strategies for disease right now is to consider canopy closure fungicides on pulses and keeping an eye out for foliar disease as the flag leaf comes out in cereals, particularly if a proactive fungicide or flutriafol hasn’t been applied.
“Even though it is dry and windy, we are still getting dewy mornings and little dribs and drabs of showers, just whether there is sort of enough humidity and cooler temperatures to see some rust hot spots show up,” she said.
“And certainly we want to be protecting the flag leaf, so if you’re not protected, definitely keep an eye out for rust and look for septoria in the canopy while you’re going out there.”
Rohan Brill, Brill Ag, Riverina Region, NSW
Rohan Brill said two major rain events in the second half of August has helped build confidence in the region, with a fair bit of positivity around.
He said he’s seeing a reasonable amount of stripe rust at the moment, mostly in wheat varieties rated as susceptible such as Rockstar and Calibre, while the varieties rated as MRMS are not as infected.
“I’d say most cereal paddocks will at least get one fungicide as well, partly because fungicides are a bit cheaper than what they were, some of the good products,” he said.
Rohan said it had been a particularly warm winter, 1.5 degrees above average, and suggested that now was a good time to be on the lookout for aphids, and be ready to manage them.
“It’s another one of those jobs that doesn’t seem like much of a cost, but it’s another $8 to spray cereal aphids, say,” he said.
“We’ve really got to monitor the paddocks and have a look, and often it’s monitoring by getting into them too – I’ve walked into paddocks in the first 20 metres and often think – spray, spray, spray – but you get 100 or 200 meters out into it, and aphids can drop off a bit.
“Probably checking for those things before, say, a fungicide goes over because you don’t want to have to go and turn around and spray for aphids five days after the fungicide.
“But if it stays warm, it might also limit some of the foliar diseases too. So if we get more aphid pressure, it might actually drop the pressure a little bit on things like septoria that like it sort of cooler.”
And the final word from CCDM Director, Mark Gibberd
Mark Gibberd said it was great to hear regions were experiencing another low disease year.
“I think it’s a good thing. But there is actually a lot of disease out there, it’s just not dominating the situation,” he said.
“We’re finding disease pretty much everywhere we go, but the level of symptomatic display is really quite low.
“But that can get away really quick under these warm and humid conditions, so it’s absolutely critical that people are out there keeping an eye on what’s going on.”
Mark said the high temperatures seen throughout grain growing regions can really push the envelope when it comes to disease development as well as other pests.
“Most biological processes are incredibly temperature dependent. The warmer the temperatures that we have, the faster things will move – it’s one of the reasons why we’ve seen our crops catch up as much as we have this year,” he said.
“But it also means that we’ve just got to be super cautious – things can get away and move very fast if we don’t have the right protection in place.”
Liked this blog? Why not listen to the full interviews on the Crop Disease Podcast
