Cotton Seed Distributors - Web on Wednesday

Sandra Deutscher, Experimental Scientist - CSIRO and Simon Struss, Cotton Consultant Services – Theodore, explain the use of the Early Season Diagnostic Tool (ESD).

Firstly Sandra, can you say a little bit about what the ESD tool is for and then we will into more detail on how to use it?

The ESD tool is to help a grower monitor his crop vigour. It is especially important for high retention crops, when the crop is using its resources a little bit differently to conventional crops, so you can pick up problems that might be occurring in crop vigour and correct those problems early before they turn into a yield problem.

The tool is a graphical tool that compares Day Degrees (DD) accumulated with the number of Squaring Nodes (SN) per plant or the number of Nodes Above White Flower (NAWF) per plant and it compares that to a target or potential line so you know where your crop is at against the optimal potential.

It sounds like it is a good way of working out where your crop sits relative to where it should be. Could we go into more detail on how to use the system, I suppose it begins in the field with sampling, could you describe numbers and how you sample?

At the moment the crops are, or just starting to square, so that’s the time when to count the squaring nodes per plant, its around 9 to 10 nodes or to be exact, should be about 500 DD after sowing. A lot of questions I get asked are “what do I count” or “what is a squaring node”. It’s not the pinhead square in the terminal and it’s not the small ones where the sub tending leaf beside the square is still all furled up. You can call it a SN when the sub tending leaf next to the square is fully unfurled, you can see all the central veins quite clearly.

You are counting the number of those per plant, you start at the top of the plant and count down till you find the first ones at that size and then keep going until you have counted all on that plant?

Either start from the top or from the first fruiting branch. Usually I will two three lots of ten consecutive plants within a metre, that gives a rough idea and I would usually do that once a week and collect that data.

You are doing groups of 10 plants and you are doing that at three sites, would that be a field size of about 50 hectares, 30 to 40 plants. Does it matter where you sample, should you go back to the same place each time or should you try and sample in a different area in the field?

A lot of crops are variable in their crop growth, pick a part of the crop that is representative of the management area of the whole crop, usually you go back to the similar area each week.

Would there be any merit in pegging an area out or is that not going to give a representative sampling?

You can peg it out but you have to be careful not to damage the plants, it is quit difficult during the whole season not to knock a few branches off as you are walking past.

How to you get to the ESD tool on the Australian Cotton website http://www.mv.pi.csiro.au/tools/esd.cgi? Once you get to the ESD tool, the first thing is to enter the sowing date of the crop, eg 10/10/2004 (format dd/mm/yyyy). You need to find your latest weather station, there are hundreds to choose from.

You take the one that is closest to your field/farm?

That’s right, next enter your observation date, the first may have been 15/11/2004 and you found one SN, next observation date 26/11/2004 with two SN. Click the analyse button and that data will be graphed against the potential line. You can see on this example that the crop development is above the line.

Determining a SN, it is not necessarily a pinhead square, can you show us on your computer how people can look at and see whether they are collecting the data the correct way?

One of the features we developed we released the ESD tool at the start of last season is a tool called ‘What is a Squaring Node’ http://www.cotton.crc.org.au/tools/squaring.html and you will find that at the bottom of the ESD tool. As you move your mouse cursor over the terms, the picture changes. The first one is a terminal, no SN in there. Then work down the theoretical plant until you get to the SN.

Can you explain again why that is the first SN?

It is the first one where the sub tending leaf is fully unfurled and you can see all the main veins within the leaf.

Using the ESD tool to come up with figures for a particular crop, most farms have multiple fields and crops, how would you use the tool to record data for each field or farm?

Most people want to record their data, a lot of web tools you can’t record data for multiple fields. So you need to set up your own system. What I have here is an Excel spreadsheet, which replicates the ESD tool, however it does not access you DD for you. You have to go to the DD calculator (http://www.cotton.crc.org.au/Tools/Agronomy/SILODayDegCalc.htm) and retrieve your DD.

Can you show us how to download that form?

Double click on the link “Download ESD spreadsheet” once you get to the file download detail screen, right click on the download link and file ‘Save As’ and save it on your computer. It is automatically saved as ‘ESD graph’.
    
You have saved that file on your computer, would you like to open and update that file?

Open the file in Microsoft Excel. If you look down in the bottom tab it says ‘Crop 1’ you need to rename that a field/farm, right click on the tab/rename/ and type in the correct field/farm name. For multiple fields, go to edit in the main menu, go down to move or copy sheet, click on ‘create a copy’ and OK and the is our next field. Rename this field, and so on.

You could put all of the fields on a particular field on one sheet?

That’s right. It is a good idea to set your fields up before you enter any DD or SN data.

Then you could save that file as a particular farm name?

Go to ‘file’ on the main menu and ‘Save As’ and call it ‘ACRI’ for example.

How do we actually enter the data into this sheet?

You need to go to the DD calculator on the CRC website, once you have found those DD you need to enter those figures into the yellow boxes and your actual SN counts and obviously NAWF counts once the crop starts flowering. As you progress through and enter your DD and SN counts the graph will automatically update the line for you. This way you get to keep the result, and it is a little more flexible than the website.

If you are experiencing problems, you can contact Sandra Deutscher or Dave Larsen - Phone (02) 6799 1500

Simon Struss, Cotton Consultant Services – Theodore

To a large extent we are successfully using the ESD tool to monitor SN production. Most of the crops, because we have had such a good run this season with rainfall, we have had no crops go into stress. So we would normally assume that all our crops would be running above that line in any case so far as SN production relative to DD accumulation.

A lot of your crops are approaching the section where you are looking at NAWF?

In this particular year, obviously the SN production and NAWF are of equal importance, because we have had the rain this year, it was always going to be above the line right up until flowering, occurring next week. We are hoping to get most of our crops to slip into flowering with at least 8 if not 9 NAWF. This is where I think the critical stage of the crop will be and that’s the critical stage for accessing that. We can use the ESD graph to maintain or verify that the crops have crossed the line at the 9 NAWF point. It is our intention to keep them revving at that pace for certainly the first couple of weeks and then we will start to tighten up at the water end and/or Pix and hopefully set most of the crop during this period.

Further Information:  Robert Eveleigh, John Marshall, Craig McDonald or David Kelly