Thank you for getting everyone excited Ollie, and thank you for the opportunity to come and share with you some of the research that we've been doing looking at some early applications of Mepiquat or Pix, and some of the case studies that we've been doing across cotton regions.

So in cotton it's very exciting to focus on the reproductive growth and yield because that's what's giving us our money in our pocket but it's also really important to consider the support structure of stem and leaf.

Because cotton is a perennial plant and it does require a little bit of manipulation of the resources that we have and managing the vegetative and reproductive growth we need to know that if the balance of vegetative to reproductive growth becomes out of out of balance, excess resources above the needs of the reproductive growth the plant can start putting that into lush vegetative growth and we can start getting the plant growing bigger and leading to self- shading and fruit loss - which is similarly to what we see in these photos.

We know that we can if we get that excessive vegetative growth we can have plants growing really tall putting on lots of leaves and not much fruit. We also know that we can control that with application of Mepiquat chloride, which is also commonly referred to as Pix.

So Mepiquat chloride or Pix, is a gibberellic acid inhibitor. It inhibits the formation of gibberellic acid. The gibberellic acid are hormones that stimulate the growth of the cotton and contribute to the cell elongation and expansion.

So if we inhibit the production of gibberellic, those hormones, the gibberellic acids and we apply mepiquat chloride to cotton, we can start to see those effects in the form of smaller and darker leaves, shorter internodes and a smaller and more compact plant.

We can also use mepiquat to achieve a greater uniformity across the the crop and and facilitate cut out and encourage maturity.

We know that some of these things are really important, particularly in some of the shorter growing seasons/regions.

Mepiquat chloride we can also use to reduce the canopy and the leaf that we're trying to get rid of and lead to a more deficient sorry a more efficient defoliation and picking and making that end of the season a little bit easier.

So the use of mepiquat chloride in cotton systems is not new and there's been lots of research done, but a lot of the recommendations are around early flowering and applications at early flowering and later towards cutout. But we know that there's a growing interest in applying mepiquat earlier in the season and trying to manipulate those vegetative and reproductive balances earlier on.

So this is the ADAMA RX-380 label for mepiquat and we can see highlighted that there's that interest that we can apply mepiquat as early as early squaring and we've got a couple of options in terms of rate. So 25 to 60 milliletres per hectare.

But there hasn't been a lot of research in looking at these rates of application and how early we should be applying mepiquat across lots of different regions. We had the opportunity to collaborate on a one-year project with CSD and CRDC where we were able on a project where we were able to go out to growers and consultants and get a feel for what questions people had in terms of early season mepiquat applications.

We saw a common theme start to emerge. The questions that we that we were coming up against was well how early should I be applying mepiquat and of these rates how hard should I be applying early on. And then there was also a number of people questioning are there any differences in how we should be managing different varieties.

So we were collaborating with growers and consultants across different regions and we were able to set up experiments at Cecil Plains, Wee Waa, Aberdeen and Griffith, so four experiments across the regions.

When we think about that sort of first, I guess they're two questions, but those first couple of questions: how early and how hard do we go. I'm going to show you some yield results.

We're looking here we're going to look at yield in bales per hectare but it's relative to unsprayed cotton at each of the locations. The zero is the unsprayed cotton and as we follow that arrow up that is improved yield relative to the unsprayed cotton. And then our application rates, we're looking at sort of a high and low strategy with the low being in the lighter gray and then the high rate being a dark.

So at Cecil Plains we can see we saw that relative to the unsprayed cotton we're seeing some small/some increases with using mepiquat early. At Wee Waa we didn't really see a lot of difference with our early season in terms of yield with our early season mepiquat strategies. It's not actually very different to not spraying mepiquat at all. And in Griffith we managed by some of our early season mepiquat strategies we were able to achieve a 1.2 to 1.8 bale per hectare increase compared with unsprayed cotton.

So if we think about this first part of the question, how early should we be applying mepiquat: what our results are showing is that although we may be able to achieve some advantages in yield with applying mepiquat early in the season, it's not really a one size fit all. It does vary across locations. And if we think about Griffith as has already been mentioned it's a shorter season that we have to contend with in those shorter season environments and so you've got that limited time to grow the crop and manipulate that vegetative and reproductive growth.

So then if we think about well how hard do we apply mepiquat? If we compare that low rate to the high rate we can see that at Griffith we're losing by applying that high rate high rate of mepiquat we're losing about half a bale per hectare compared with that low rate application. So if we're thinking yeah how hard can we go we can go too hard and I guess if we think about the reasons why, we're restricting vegetative growth early on and we're not enabling the plant enough resources to be able to put that into yield.

So this is some of our Aberdeen, our data from Aberdeen, and similarly we're looking at yield but relative to unsprayed cotton. And similarly we see that compared with the unsprayed cotton by using the mepiquat we're achieving an extra bale per hectare. However if we're asking the question is there a difference between varieties, these two varieties that we that we compared there was there was no difference in how we should be using mepiquat.

If we think about what it is that we have learned and everybody loves the answer oh well there's no hard and fast rules, that sort of stands but we can sort of gain some insights from these studies. So while we've been able to/with the early season application of mepiquat while we've been able to manipulate the canopy it really depends as to the season and sorry the region and what we're trying to achieve. So we saw that at Griffith being a shorter season that managing mepiquat early did have an effect but we also found that if we went too hard then we could limit the yield compared with applying it a little bit/a lower rate earlier.

So the the take home message is that we probably shouldn't be applying it in a prescriptive manner. We also found that with varieties that we shouldn't be basing those decisions based on variety alone. So like in this this picture we need to be monitoring the crop growth and we need to be taking a holistic approach. We need to be also considering factors such as the nutrition, irrigation, environmental conditions as well as understanding our plant growth rate when we're making those early season mepiquat decisions.

So I would like to acknowledge the funding from CRDC and CSD through the Richard Williams Initiative. I'd also like to thank each of our growers and consultants that we were working with. And thank you to our CSIRO colleagues as well that have enabled this study. Thank you.