Season update December 2024

Welcome to December's season updates. There are quite a few things we need to quickly cover. I'm going to touch on cordon shaving. We'll talk a little bit about fruit development in general and then disease control. But particularly, we're probably going to spend most of our time just looking at the control of Q. fly, Queensland fruit fly, and what we need to do about that. Firstly, just in relation to the cordon shaving, there was some concern expressed when cordon shaving first came about, because it's quite harsh. It does take off a fair amount of wood. The concern was that it was taking off too much potential or cambium, if you like. But we weren't going to get those replacement shoots. So it'll be interesting to see over coming seasons how many replacement canes we get per metre of cordon, of course, and where they actually arise. Sometimes when we suppress some shoots, some latent shoots, hidden shoots, hidden buds, spring back into life. Fruit development-wise, we've gone well past fruit set, obviously, and gone through bunch shatter in the various varieties where this is a problem. We're in the Carina patch here, and these bunches are nice. Well-developed, coming up to size. They're still hard, a good thing, particularly when it comes to Q. fly, and looking pretty good. So the bunch structure's nice and loose. There is a little bit of powdery around. Just about everybody's had it. Just about every vineyard's had it. But just how severe it's going to get from here on is the issue. OK, what we've got here is a mat cup hanging underneath the canopy. Mat cups, as we've probably pointed out a few times, are a male annihilation treatment or technique. And the idea is that it's got a female pheromone in there, so the males think there's a female who's wanting to mate with them. They front up to these things and have a bit of a chew of something and they end up dying because there's insecticide in there. So those cups would have been put out about two months ago, two and a half months ago, maybe, something like that. They will only last about three months, so that's sort of getting us into the January period. Now's the time to be really looking for what the numbers are and mating accordingly, particularly around areas where there was lots of evidence of fruit fly last season. That's a good spot to start. As we've seen, some of the earlier varieties, drying grapes and in the table grape industry, they're starting to be affected now. Be affected will mean you can see where the female has pierced the skin. There'll be a little black mark, and depending on how long they've been in there, if you crack that berry open, you'll find that there's probably going to be maggots in there. So that's why having those traps out there to identify where those chew fly are is important. And then there's the baiting program. On this particular property, baits are being laid out now. So baits are being sprayed, rather. They're sprayed on the post down low, and the idea is to try attract all the flies with a yeast protein. So that's what they're after, protein. And then once they've taken that, had a feed of the yeast protein, the insecticide that's mixed with it will kill them. Once we've started doing that, of course, you start knocking down the number of generations that are happening. So that's why it needs to be more or less ongoing because there are many, many generations in the berries coming through. So it's not just, I'll do it once this season. It's a commitment all the way through. OK, so that pretty well wraps it up. I'll talk to you next month, and Merry Christmas. Take it easy on the road and good things.