Sandra Deutscher, CSIRO/ Cotton CRC introduced new features of the Crop Diagnostic Tool. David Kelly (CSD, E&D Agronomist) and Tony Taylor (Border Rivers Consulting) discuss their experiences with the Early Season Diagnostic Tool in the 2004-05 Season.

Sandra, there has been a change to the Early Season Diagnostic tool. It is now the Crop Development Tool. Can you tell us what are the changes and how do we use this tool this season?

The main change to the Early Season Diagnostic Tool is that you can now set up multiple crops whereas before you could only look at one crop, so it is a fantastic improvement to the old system.

It’s now called the Crop Development Tool, and the reason for this is because we have added a fruit development curve to the node development graph. So now you are not only tracking your node development progress but you are also tracking the fruit development as well, which is quite important.

Sandra, take us through the use of the Crop Development Tool?

A grower or consultant may like to set up their crops or several crops and then they would go and monitor their crop early squaring right through to when its flowering. They would enter that data into the Crop Development Tool and the analysis of that data will appear in two graphs.

The first graph will be their fruit data compared to a potential fruit curve and the second graph will show their node development data compared to a potential node development curve.

How can they use that in the management of the crop?

With the node development graph, if their crop isn’t tracking along the line then they might like to look at whether the crop is water stressed, whether the crop has nitrogen stress and look at other things other than just node development. With the fruit development, it’s a very similar story although they might want to look at whether there is high pest pressure and look at their retention rates as well.

David Kelly, CSD Extension & Development Agronomist, Border Rivers

Why we used the ESD Tool:
Last season we used the Early Season Diagnostic Tool to monitor a lot of our large scale replicated variety trials. We did that to try and gain a better understanding of how the different varieties react to different situations in terms of their determinacy and their maturity. It also enabled us to provide a running commentary on how those variety trials were progressing and we reported that on the ‘Trials on Line’ on the CSD web site.

The Benefits of the ESD Tool:
The benefits we got out of the Early Season Diagnostic Tool last year was that it provided a lot more value to our large scale replicated variety trials. Not only did we get yield and quality data at the end of the season but we also had some good information about how the different varieties reacted to different situations during the season, whether that be irrigation, application of plant growth regulators or climate. From that we were able to develop some management guidelines for each of these varieties.

The benefits really came down to four key things:

The first thing was a one off measurement using the ESD Tool provides a reasonably accurate indication on how the crops progressing compared to your ‘ideal line’.

The value of the data really increases however if you start doing regular, weekly monitoring where your able to get an indication on how the crops are progressing using that the shape of the development curve. It indicated whether the crop was becoming more vegetative or whether the crop was slowing down. We were able to pick up really subtle differences in the way the crop was growing.

The third key benefit is as the end of the season you end up with your completed early season diagnostic tool graph and that really provides a good post mortem of how that crop performed. It is very interesting when you overlay some of the management decisions and the climatic conditions over the top of the timing on the early season diagnostic tool. It is a really good learning experience to look at how the crop reacted to different situations and maybe you can do things differently in the coming season.

The fourth thing is a secondary benefit. Collecting the data for the ESD Tool really makes you get in and have a good look at the crop. The process of counting the squaring nodes and the nodes above white flower really makes you consciously get in and have a look at that crop. There was a number of instances last year where after doing the ESD measurements we were able to identify some other things that we needed to be monitoring, and one example was the propensity of some varieties to put out vegetative branches and the timing when this happened.

Considerations in using the ESD Tool:
First and foremost, the value of the information that you get out of the ESD Tool really comes out of the quality and the quantity of the data that goes in.

Firstly, Quantity of the data. As I said before, a one-off measurement gives a relatively good indication of how the crop is progressing at any particular moment in time but the value really increases when you start getting regular dots on that graph. You can start to see what the slope of those lines are.
I think a lot of the people that said the tool was of little value probably only did irregular or very infrequent sampling and so you don’t get a lot of value out of it when you don’t sample regularly. So first thing is sample regularly, you will get a lot more value out of it.

Will you use the Crop Development Tool This Season?
We will certainly be using the Crop Diagnostic Tool this year in monitoring a lot of our large scale replicated trials. The value we got out of the Early Season Diagnostic Tool last year was great and I think the introduction of the fruit development component of the new Crop Diagnostic Tool will really add another dimension to it.

Some of the things we are going to be thinking about is the regular monitoring again, which is very important. I think one-off dots on the graph are going to be of marginal value but once you start seeing a curve take shape as the fruit accumulates, that’s where you are really going to start getting a lot of value out of it. All of the data from our large scale replicated variety trials will be put on the ‘Trials on Line’ page on the CSD web site so it will be an interesting way to track the progress of those trials and those varieties.

Tony Taylor, Border Rivers Consulting, Goondiwindi.

Tony, how did you use the Early Season Diagnostic Tool last year?

We used the tool in all the Bollgard® II cotton. We grouped the Bollgard fields into management units of a similar soil type, similar plant dates, similar variety so you might have two or three fields grouped as one management unit. We then set up an ESD table for that group of management units, sampled those fields weekly and recorded plant mapping data, fruit retention, plant height and we were able to get some growth rate data out of that.

So you did that for all your clients?

We did on every farm that had Bollgard. We grouped all the fields into management units and just ran the ESD Tool for every management unit. So the farm with ten Bollgard fields might end up with four or five ESD summaries of the fields grouped together.

What sort of value do you think you got out of doing this?

I think it helped. Any data that helps you manage the crops is going to be valuable. We are on the farms two or three times a week checking the crops and scouting the crops. The ESD Tool just allowed us to use the plant mapping data to graphically represent the crop growth rate which I think was valuable. You could see whether you were behind or in front of the model crop growth curve. We also added fruit load into another box on the ESD so it was a combination of fruit load as well. We did fruit counts at the end of the season, so we had them on as well. It was just a good way to summarise the crop growth on the physiological development through the season so if we were rapidly above the line we would look at putting on Pix, if we were below the line, we had some farms at Mungindi last year got some really big rain events, and the graphs dropped below the line. The fruit retention dropped down and you could see it on the ESD Tool. In those fields we ended up doing a bit more fertigation, we water ran some more Nitrogen and looked at a few foliar applications to try and pick them up and get them moving and get above that model crop growth and development line.

You have obviously used it to tweak your management during the year. What about the completed graph, do you think that is a good post mortem of the crop?

It is I think. Annually we do a farm report for each farmer and part of the farm report this year was using the final ESD and a culmination of all the final data presented on one page and I think it was. You could look back at that crop and insert little arrows where we put PIX into the system and you can see we had a comment box where we made comments on how the crop grew and developed and whether it dropped down below the line and you could see, you could correlate the day degrees with a massive rainfall or any stress on the system and it was reflected in the graph so it was a good post mortem. You got the farm yield or the field yield, go back over and look at the ESD data and draw some sort of conclusions if there was a problem.

With your years experience of using this, what sort of advice would you have for other people and what sort of changes would you make on how you use it in the coming seasons?

We are keen to use it again. Garbage in and garbage out. You get bad data if you have someone collecting the data that walks into a spot that is not representative of the field or fields, so I would teach the people collecting the data to accurately plant map and pick a representative spot.

This year we are moving to have permanent plant mapping spots that we can get good data from but it is a little bit time consuming. I think however the value of the data and the end of year reporting ability of it is worth doing.

Just looking at some of your graphs. You have taken the data fairly regularly. Do you think there is more value in very regular checking than just the sporadic or irregular checking?

We have got a weekly plant mapping or fruiting factor program in the consulting business already that we were doing in previous years. The ESD Tool just becomes a bit more accurate if we sample regularly and the crops changing so much. It is a pretty dynamic system so the more that we can sample the better the data and more consistent the data I think.

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