Transcript

Good morning. My name's Andrew Whitbourne standing in front of a sweet corn crop that I've been involved with for the last probably 30 years, in the East Gippsland region. Started as a field sampler or field officer for Edgells prior to doing university and then coming back and working for E.E. Muir and Sons, which is now Muirs which, basically I’ve been looking at doing sweet corn monitoring, spraying and timings and stuff for the last 20, 25 years. Just with regards to Fall Armyworm it was first into Australia in 2020 through Queensland. Can you remember back to then and see what your initial reaction was of hearing it was in Australia? And potentially coming through. Yeah, the reaction was pretty quick for us because, obviously Muirs being a national company or reseller, that we do have a store that works out of Bowen and Bowen was one of the first areas that was really hit. I remember speaking to the agronomist up there at the time who actually looked after some of Mulgowie’s crops up there and a couple of organic guys and the devastation was really impactful and so I knew that this could become a major factor for us.

Once it was confirmed into Victoria, was there any major changes you needed to make for growers here? We really didn't know what impact it would have because seasonally we do get seasonally, like obviously, Heliothis has been our number one pest for sweet corn for the last 20 years, or 25 years or forever, and that changes on a year to year basis, depending on flights and monitoring and stuff. So, we really didn't know what the Fall Armyworm was going to be like in that respect. So, we immediately started doing monitoring straight away with lures and pheromone traps to find out what sort of beast we were going to be on. We were all very worried at the time because, since that first happened, I'd been to Bowen and spoken to both the QDAF guys, and also being out on farm with the growers and could see that the organic growers, as I said, they were actually growing sweet corn up there, they'd just given up. They just couldn't handle the pressure that they were under. The other guys were really struggling. So I knew what impact it might have, but I just didn't know how it was going to affect the East Gippsland region.

What were some of the reactions from the growers in Victoria? They were concerned! Yeah, definitely concerned because back then there was a lot of press about the actual thing. There was a lot of stuff on ABC radio from the country hour and whatnot about what impact it was having on the vegetable industry. So yeah, they were concerned. And as I said, we just had to start monitoring to start seeing what sort of pest we were going to be dealing with into the future.

So looking back on that early period, what were some of the biggest challenges the growers faced in managing it? Really it was the monitoring side of it and really to this, to even to today we've had it for like three years or so where we've been doing major monitoring. I think the implications of what could happen going forward, we're still not completely sure especially like we are obviously dealing with fresh market sweet corn for myself, but definitely for the maize growers, we've got a lot of fruit fodder crops growing in the area for dairy production and who generally don't normally spray. So, we are still trying to work out what the impact it may have going forward.

What would you say some of the biggest learnings have been out of the last five years? The biggest learnings probably is the impact that it has. Like I think we've got to the stage now where we're wondering what sort of weather patterns are going to occur for us to get big increases in the actual number of moths. So, we've monitored now for ever since we started having it, which is, four or five years ago. And we don't seem to get flare up of moth until in mid to late autumn. So, we start monitoring around October and moth numbers generally aren't starting until about January. And then the big numbers are really hitting really around now (March), which is, which is, different. As I said, Heliothis has been our number one pest in the crop, and we generally get two flights of them between the two species. So, we'll get one flight in the sort of third week of November or the middle of November, and one in about mid-February. So, we know that, and that's been happening for 20 years, but we just don't know where the Fall Armyworm's going to happen and what weather events are going to cause it to migrate from the Queensland area where they're in big numbers down to Victoria.

If we do start to see Fall Armyworm a lot more in Victoria, yep, what are, say three good tips for a grower to consider for fall armyworm control? Realistically, the monitoring is the number one. So, both pheromone lures and monitoring what moth numbers are around and then seeing what impact it has on your actual crop. Because you've got to understand when Heliothis are around, they're generally laying one egg really of a nighttime or whatever, whereas the Fall Armyworm can lay up to 200 eggs in a cluster at a time. So when that all hatches out, you've got 200 grubs against one grub. So even though the Heliothis numbers might be a lot higher, and so that still makes you think, if the Fall Armyworm comes to what I saw in damage in Bowen, and even around Gatten yeah, we're, it's a serious pest that we have to try and thin. So monitoring is the key definitely.

Is there anything that you think the Victorian growers could do now to prepare? Yeah, I just think just having somebody in your fields all the time because you'll see even in young corn that's generally like in a sweet corn crop, we don't really start spraying it until silking stage. So, you know, that's really around 60 days into a hundred-day cycle. Whereas if the Fall Armyworm comes in, we have to spray a lot earlier. So that's probably the major difference because of the damage that they can do, yeah, we have to go earlier.

Is there anything that you think research organizations, government or funding bodies could do next to better support growers?

Really QDAF have done a really good job up in Queensland and we've had Melina down from QDAF and run workshops through Agriculture Victoria, which has been really helpful to the growers because it gave them a perspective of what can happen. So, I think that has been a really good win. So going forward, I really think we really need to keep monitoring, and we’ve got to work out what sort of weather patterns are going to cause an increase in the number of Fall Armyworm we see. Like, you know, do we get a certain weather event that we say, okay, in the next two weeks we should see a real increase? So that's probably where I'd say that the new research needs to come.

We are now monitoring crops that are only 30 days out of the out of the ground, which, normally we wouldn't have to. But we just have to because if you can soon walk through a crop, and with fall armyworm, you'll see the damage within a sort of three metre radius. So, of those 200 potential grubs that actually emerge from the egg lay, they don't go in a big area. So, you'll see a real area and then you might walk 40 metres and not see a grub and some you'll come across another egg layer and more damage. So, you've got to be monitoring from basically very small in the ground, and that's the difference with Fall Armyworm to Heliothis, because once we would not spray that, but we have to with Fall Armyworm. So potentially the growers are going to get another three sprays per crop if we have a big Fall Armyworm season. Yeah, so what we are doing here is, this is obviously, we just put this at the back of the Ute so we can show you what we'd actually do in field when it comes to sweet corn monitoring. So generally, as a rule, we get like a field lens, and we'd checked the actual silk here for any egg lay, and that's normally for Heliothis. We find that the Fall Armyworms are generally on the bottom side of leaves down near the bottom where they actually like to lay. But then we still need to check the cobs for, actually if there's any damage. So, you just peel back the cob, check the silk. You'll soon see if there's a grub because there'll be damage straight from the start right down. So, we just go through check, generally on a rule when it comes to sweet corn monitoring, we generally would check per, say if you had a hectare of sweet corn in, we check up to probably about a hundred cobs during a scout, what we'd call a scout. And that would be a random scout, you'd walk through the paddock, and again you're checking the silk for eggs. I have actually found it pretty hard to find the Fall Armyworm, like we can find Fall Armyworm damage and it's pretty hard to find the egg lays. It can be because as I said, they don't generally unlike Heliothis that generally lay on the silk, they generally are down, further down. You can find them, but they're generally a lot more intense to monitoring, to look for it. So here you can see what I mean by the damage. It's obviously had a grub in it. So, you know, you would mark that out and say, righto, as I said, if you did a hundred and you suddenly got up to over 10. Yeah, that's 10% of the crop that's potentially damaged, then you've got a serious issue, an economic threshold that you know you have to try and spray, and you really want to stop that damage before it actually occurs. So, you're really trying to grab, if the silk is where the egg lay is or Fall Armyworm's underneath or down more, you'd need to attack that stage before they actually hatch and then go into the actual cob. Yeah, that's what we do. So, the emphasis really is on monitoring? On monitoring. Yes. Correct.

The main issue we've got with Fall Armyworm is the fact that we have to spray so early in the crop cycle. So instead of like when we didn't have Fall Armyworm, we only really had to put four, maximum five sprays on to control Heliothis. But with Fall Armyworm, we're going a lot earlier in the crop. So yeah, you might end up doing eight sprays on a particular crop. So obviously resistance becomes a big issue. Reading up on Fall Armyworm information from overseas and stuff, these are a pretty resistant beast once it gets going. So that's our main issue, is how to handle the amount of sprays we have to do to control Fall Armyworm in sweet corn, and what resistance strategies we come up with.

Is there anything a grower could do to help prevent resistances? We’ve really just got to look at the different groups, the insect with what lifecycle we got and the different resistant groups so we can manage our rotations properly. At the moment we do not have a group 30 in the system that whether it be a permit or a proper registration, so it restricts us a little bit on that. We've got group six, which is proclaim. We are having in Victoria, we are having a little bit of issue, so we're getting Syngenta to do some work on that, on resistance and whether we're using the product wrongly or there is resistance to it. So, we're doing some work on that. And other than that, we've got obviously the group 28 and then success. So, I suppose we just have to make sure that we can get as many groups in the rotation as we can and that's the issue we're working through. And regular monitoring to decide whether you're going to,.. Yeah, and that's the issue. We've been very lucky this year. This year the Fall Armyworm hasn't been an issue, so we've only actually put, from my knowledge, we've only actually have put one spray on early, whereas this time last year, we'd probably already done probably two sprays early. So, we're monitoring numbers and monitoring is the key. So, we're monitoring the numbers of Fall Armyworm that we're getting down south in Victoria, and so touch wood, we've been lucky this year, but who knows what's to come in the future.