Hi everyone it's really great to be here to talk to you about seed quality testing. CSD has a very comprehensive quality assurance program. All seed undergoes about 50 tests before being sold, that includes numerous individual tests as well as many of those tests being conducted at multiple points in the production cycle. I'd really like to go through the entire quality assurance program but we'd never get to the bar, so today I'm just going to focus on the information in the statement of seed analysis.

So firstly where do we get our seed quality information. There are two main options so for the 20 kilo bags you can use the QR Code system. You simply scan the code on the front of the bag this will take you to the CSD website. If you follow the link this will then provide you with the specific statement of seed analysis for that bag of seed. Alternatively you can go to the CSD website and look up the statement of seed analysis by providing the variety the treatment and the AUSLOT number. This is an example of one of the AUSLOTs produced this season: I'll use this as an example to go through how the information is presented.

It's starting with the overview. Now this is pretty straightforward at this point you've already placed your order so you're familiar with the variety and the treatments. The AUSLOT number is simply the code for that seed lot, represents a treating run with a maximum lot size of 24 tonnes. The test date is the date that refers to the germination results which are provided within the report.

Moving on to the Purity. So in this case purity refers to physical purity as opposed to varietal purity or transgenic purity which are other aspects of seed quality. The physical purity incorporates the pure seed percentage in this case obviously that's cotton seed, the percentage of other seeds and the percentage of inert material (which is seed coat fragments and other plant material). This is simply shown to demonstrate that the seed lot is within the minimum 98% for physical purity and the 0.2% of other seeds which is the maximum. Since cotton seed is highly processed we don't really ever see any other seeds coming through the finished product, so this isn't really something growers need to be too concerned about.

Also presented with the purities is the mechanical damage. Unlike physical purity there's not actually a specific threshold for mechanical damage but as Ian spoke about earlier we are trying to minimize the levels of damage. At CSD we assess mechanical damage using a microscope and any seeds which have damage which penetrates right through the seed coat to the embryo is considered damaged. This can this can include everything from a pinhole damage which you might not even be able to see with the naked eye, right through to the major damage so you can see the example of that range of damage in the photos there.

So moving on to arguably the most important aspect of seed quality the germination. CSD provides results for both the warm germination and the cool germination percentages, so I'll just go through how these tests are conducted and how you can use utilize this information.

All germination testing conducted by CSD follows the standards for germination and seed vigor testing set out by the International Seed Testing Association and the Association of Official Seed Analysts. It's important to note that these are all conducted under lab conditions using the rolled towel method so they are not expected to predict field establishment.

If we compare the two test methods, have a look the warm germination test is conducted at a cyclic 20/30 temperature regime and it's assessed at four and again after seven days. Whereas the cool germination test is assessed at constant 18 degrees and it's assessed only after seven days. But for both tests to be considered normally germinated the seedling needs to be free from abnormalities, free from primary infection and have a minimum seedling length of 40 mm.

If you have a look at this information you can see that the tests and the manner that they're conducted is quite similar, however the information that they provide and how that information should be utilized is actually quite different.

If we start looking at the warm germination test this tests the seed viability or the maximum germination potential, therefore it's conducted under ideal conditions and it's designed to give the seed every opportunity to germinate. So in these favorable conditions you can see there's a really large distinction between those that are germinated and those that haven't. On the left uh it's typical example of four day germination and as you can see they're actually four times the minimum length after four days and they're actually given till seven days to reach this length requirement. In these favorable conditions really what it's telling us are the seeds capable of germinating or not. Not really testing how well they are germinating. Now this viability is still really important information: this is the standard test for quantifying the quality of planting seed and it's obviously important for adjusting your planting rates, you need to know how many you're capable of germinating. But when you look at this it's setting the bar pretty low isn't it.

When CSD quantifies their seed quality they want to have a higher standard because we understand that you're not actually planting into ideal lab conditions. To have that higher standard for quantifying seed quality this is where the cool germination test comes in. The cool germination test measures seed vigour. If warm germination tells you are they capable of germinating, the cool germination test tells you how vigorous is that germination. The cool germination test is not actually a requirement, CSD doesn't need to conduct the test but we feel that the information it provides is so valuable we do conduct it on all seed lots and we choose to provide that information to growers.

As a stress test it's conducted in less than ideal conditions but why specifically is it 18°? If you have a look at the example we've got here this is the same seed lot and it's been germinated for seven days at a range of different constant temperatures. At 12 degrees there's no development at all. Fourteen to 16 there's radical emergence but there's not sufficient germination for us to assess the germination. If you have a look at down the bottom we've got the 20 degrees where there's quite a bit more development but there's insufficient stress at this point for us to differentiate between seed lots for vigour. So that leaves the 18 degrees as being the optimal temperature for differentiating between seed lots.

Just to explain what I mean there by differentiating between seed lots I've got an example. We've got seed lot A on the top, seed lot B on the bottom. This is after they've had their germination test. Both of these seed lots had the exact same warm germination you can see they also have the same percentage which have started to develop after the seven days. But when we incorporate the 18 degrees, the seven days and the 40 mm radical length we can then differentiate that the top seed lot has 40% cool germ and the bottom seed lot has 60% cool germ. This then allows us to know seed lot B has higher vigour, and we know the relative vigour of the two seed lots and that can help us to make decisions.

How this would actually be applied in the field, we have Sarah Parkes who will be speaking after me and she's going to give her insights as to how they they've utilized this information for planting, so I won't go into that too much.

Everything that I've been speaking to so far has been looking at quantifying seed quality, but the relationship between germination and temperature isn't just a reflection on seed quality. It's actually an inherent trait of the species. We've done a lot of lab based trials looking at this and we've also validated that in the field but it's hard to draw direct comparisons in the field because we can't control temperature.

To demonstrate the influence on temperature on emergence we've used an intermediate process which is our thermogradient table - so this acts as an intermediate between lab based tests in rolled towel and emergence in the field in soil, but it allows us to have control of the the temperature parameters. This is the thermogradient table and this is Pille who is our lovely technician that has assisted with these trials. If you can see there are soil filled troughs that are running vertically in the photo, so each of these have been sown with seeds right across. Underneath the troughs there is a temperature controlled surface. For this example we've got an increasing temperature gradient from 11 degrees (the trough on the left) across to 20° (the trough on the right). I'm just going to start the video now you will see that at these temperatures emergence is very slow. For this trial we used Sicot 619B3XF as it has very high seedling vigour. We also used a seed lot with very high germination and seed vigour so this is this demonstration is supposed to represent the best case scenario. We're about at seven days now and you can see the first emergence in the 20 degrees trough. Each of these seedlings emerged soon after but when you have a look across to the lower temperatures each of the lower temperatures had slower development, lower final establishment and they were generally less healthy seedlings. If you have a look at the trough labeled 16 this was the 16 degrees, there was some movement at the surface but there was no emergence at 16 or lower. We took this trial all the way out to four weeks at which point there was definitely no further development and so this picture shows that the maximum establishment that we had for each of those temperatures. As you can see more than half of those actually had no emergence whatsoever, so we've dug them up so that we can demonstrate the level of development for each of those temperatures. Similarly to the lab based tests, the 11 and 12 degrees where there is no development whatsoever. Thirteen and 14 we had radical emergence and then the the seed has died there was no further development. Fifteen in 16 there was quite a bit develop of development but there was no emergence whatsoever. And from 17 through to 20 there was emergence but the the closer you get to the 20 degrees the more rapid the development was, the healthier the seedlings, the higher the establishment. So this is a good demonstration for the thresholds for the soil temperature I won't go into that any further as we'll have John and Whitey covering on that project soon. That's all for me, thank you very much.