NIAB - National Institute of Agricultural Botany

Orson's Oracle

Weeds are a priority

Posted on 09/03/2012 by Jim Orson

I’ve been speaking at series of meetings in South Australia, New South Wales and Victoria, organised by the GRDC, HGCA’s Australian equivalent. However, the GRDC budget is a little higher at A$110 million (about £75 million). The Government provides GRDC with another A$55 million, so the total budget is A$165 million, which represents about half of the total research spend in grains. This means that researchers are very close to practical issues.

The top research priority is weeds. Annual rye-grass (a different species to UK rye-grasses) has developed resistance to nearly all herbicides, including trifluralin and glyphosate. Hence, their arable systems are near to the edge because of this weed.

This year there is a new pre-emergence herbicide from Bayer called Sakura (ai pyroxasulfone) that currently offers reasonable control; unless seedbeds are dry. Weed scientists say that it’s probably only time before resistance develops to its mode of action. One said that Sakura means cherry blossom and you know how long cherry blossom lasts.

Sakura has a new mode of action to Australian grower. It is being tested in Europe, but not by Bayer; the chance of registration in Europe has to be questioned because of its persistence in the soil. Long persistence also provides a greater opportunity for it to move into water.

In many ways, the rye-grass situation in Australia is very similar to black-grass in the UK. There are no longer any real post-emergence options and it is now all about stacking or sequencing pre-emergence or early post-emergence options. Even then control may be incomplete, so cultural control is being adopted.

One option is to grow more competitive crops, but of course too much crop green matter may put yield at risk if there is a ‘dry finish’. The weed is vulnerable in one respect; about 50% of the seed is still on the plant at harvest. Hence, farmers have adapted combines to collect the seed in a towed trolley or put it through a towed seed crusher. Alternatively,  they have adapted combines to leave a narrow swath called a windrow. These are burnt when the fire risk is low, usually in March or April, three to five months after harvest. The narrow swath creates a higher temperature burn to kill the rye-grass seed harvested with the straw.

Post Office - Australian style

Other problem weeds include the wild radish, the same species as our runch, and fleabanes. Herbicide-resistant wild radish is a major issue in Western Australia and fleabane seems to be increasingly an issue in most arable areas in Southern Australia. Again cultural control measures are being adopted. Some wild radish seed can be collected by the combine and it is vulnerable to burning. However...and keep this to yourselves...some farmers are going back to ploughing to control problem weeds after many years of little or no tillage.

Some of the GRDC meetings I spoke at were held in small country towns. These are in crisis, as witnessed by the number of closed shops. The increased productivity of farming has resulted in a dramatic reduction in employed labour and many farmers have given up sheep because of the poor returns from wool. Frequent droughts over the past ten years have cut down the spend in local shops by farmers, with many smaller settlements now down to a couple of inhabited houses, despite the number of post boxes at the local ‘post office’.

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Solar bliss

Posted on 29/02/2012 by Jim Orson

You can have enough of kookabarras. To be fair, when this iconic bird 'laughs' at 30 minutes after sunset it’s great. But, it can be wearing after several mornings of being woken up 30 minutes before sunrise by the same cry.

I’ve visited a few farms and given a few talks during my visit to Australia so far. When it seems appropriate, I’ve asked ‘what’s the one major introduction that has influenced farming systems in Southern Australia?’.

Initially it was wire fencing to keep in the sheep, and then over time it was corrugated iron, treated fence posts (against termites), hydraulics, bulk handling of grain and the plastic water pipe.

The current generation of arable farmers mostly say ‘Roundup’; it enables summer weed control to help ensure that as much soil moisture as possible is retained for the crops sown in the autumn and avoids the need for cultivations over the summer that could lead to horrific wind and sometimes water erosion.Corrugated Iron

It also enabled the current one-pass establishment techniques. Typically this is a knife point system, but some have adopted direct drilling with disc drills. The most recent farm I visited sows 10,000 acres in 15 days with a 60 foot wide 'drill'.

Perhaps this reliance on glyphosate has resulted in farmers not being totally enthusiastic about the adoption of GM glyphosate tolerant canola (rape). There was already glyphosate resistance in two weeds before the introduction of GM rape a couple of years ago. This made the farmers more aware of the risks of relying further on this herbicide.

So the only situation where this technology is being adopted is where there tends to be a weed species that cannot be controlled by conventional selective herbicides, and the farmer feels that there is the probability of a reasonable crop. The cost of the hybrid seed is deemed to be too high for the more droughty areas so in these areas, triazine tolerant rape in conventionally bred varieties is often the preferred option.

So the rate of uptake of GM herbicide tolerant rape over the last couple of years has been slower in Australia than in other countries where it’s been introduced. In my opinion, this sensible adoption of the technology has to be applauded. GM provides options, but often not the only solution and over-reliance on any pesticide can lead to resistance issues.

I did ask the wife of a sheep station owner what introduction has influenced her life the most over the past 30 years. They farm 50,000 acres on the edge of the outback and communications are not easy. I expected her to say a satellite phone or email. She said battery-stored solar power. It meant that the family could get a good night's sleep without the fridge switching on the generator. They obviously don’t have kookaburras on the farm!

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Sweet smelling stubble

Posted on 23/02/2012 by Jim Orson

Travels across Australia - cont

Farming in South Australia

I visited a farm today near Clare in South Australia.  It’s in a relatively high yielding area; achieving over 6 tonnes/ha of wheat last year.  This year the soil is still dry throughout the profile, so yields are predicted to be lower for 2012, and the grain price has dropped due to the strength of the Australian dollar.  So the financial shutters are coming down and every growing cost is being reviewed.

In neighbouring Victoria grain farmers have seen a doubling of total costs over the past 15 years.  Profit levels have remained roughly the same, but with enormous variations between years linked to rainfall levels.  Overall, growers have made money in around half the years since the early 1990s, but this hasn’t prevented an increase in debt.  Some have suffered a 5-11-year drought that they thought would never end.

Back to this morning’s farm visit.  The farmer was using soil probes to monitor water availability in the soil rather than using computer models.  Neither method appeared to be perfect, but they have a role to play in arriving at a decision where the skill and the intuition of the farmer is paramount.  A researcher recently reviewed the crop models and found them all pretty inaccurate in predicting yield, although some were OK in estimating water use.

The farmer has used ‘controlled traffic’ of sorts for the past seven years.  I say ‘of sorts’ because his combine header isn’t fitted to the system and he makes hay from oats, and many of those operations don’t fit in with the concept.

Despite the ‘of sorts’, the farmer says that water infiltration has improved to such an extent that his dams, which are ponds constructed at the bottom of slopes to catch run-off,  are no longer filling with water.  Obviously, Australian grain growers prefer the rain to be in the soil rather than running off it.

Talking to his consultant, it seems that adopting direct drilling using the knife coulters in the mid-1990s increased water infiltration rates due to soil residues being left on the surface, which reduced run-off, and an improved soil structure.  Controlled traffic may have further increased infiltration rates.

The other advantage he claimed from controlled traffic is a reduction in power required to pull the 11-metre direct drill.  He suggests that there has been a reduction of around one-third since its initial adoption.

Despite these figures, many of his neighbours have not adopted any system of controlled traffic.  This prompted a discussion on soil care.  This farmer, and another one I met later in the day, re-iterated comments I often hear from UK growers; when they take over new land the horsepower needed to establish crops is high, but adoption of measures to improve soil health result in a gradual reduction in power requirement and an improvement in yield.  These measures include working the soil only at appropriate times and using as much organic manure or amendments as possible.

This led me to ask one final question as I got into the Ute: why did the stubble smell so great?  Apparently it had recently received a locally sourced organic amendment - 2 t/ha of grape waste.  We tasted the non-waste portion at lunchtime.

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Boring Brits?

Posted on 16/02/2012 by Jim Orson

We went out for lunch last Saturday. The weather was glorious and all the tables in the garden were occupied, so unfortunately we had to sit inside. The conversation soon got around to managing risk when growing wheat in low rainfall areas of Australia. I was talking to a consultant who has been a major driver in the development of risk management strategies in such situations; we were having lunch in Bendigo, Victoria...in Australia.

Obviously, much of the risk management strategy revolves around water availability. Last year soils were full of moisture at sowing in early May (our October equivalent), but this year they could be bone dry. So how do Victoria’s farmers cope with this extreme variation, when typically rainfall after sowing could be insufficient to meet the full needs of the crop?

When I was first in Australia, around ten years ago, this was done by estimating how much water there was in the soil at the start of the season. Either a steel rod was pushed into the soil or a calculation was made based on the amount of post-harvest rainfall, providing a crude measure of how many mm of water was available at the time of sowing.

The assumption was for 20 kg of grain for each mm of moisture, and as rain fell during the season this was measured and the estimated yield as adjusted accordingly, with nitrogen (N) applied based on yield potential.

The issue with N is that there should be sufficient to achieve the anticipated yield. However, too much will mean excessive green leaf and water loss and as a result, reduction in both yield and grain size.

Now, computerised systems are used that require information at the start of the season based on a soil core analysis. Available moisture and N are measured and where prospects are good for yield and some additional N is justified this is applied in the combine drill.

As the season progresses the computer programme predicts N uptake and, based on any rainfall after sowing, expected yield. Additional N is applied if a shortage is predicted.

Water availability, along with plagues of mice and locusts, are not the only risks to take into account.

Sow too early and the risk of frost damage increases. Crops are grown through the winter and harvested in November (equivalent to our April) with the threat of wipeout due to frost at flowering. Sow too late and there is an increased prospect of yield damage from high temperatures during flowering.

Variables impacting Australian wheat production (specific variety) These risks can also be assessed by a computer programme based on weather records over the last 100 years. The image shows a printout for a specific variety at a specific location:

  • potential yield according to sowing date is the thick line;
  • the falling lines on the left are the decreasing risk of frost damage as sowing is delayed; and
  • the increasing lines on the right are the increasing risk of heat damage as sowing is delayed. 

The optimum date for sowing, assuming sufficient moisture for germination, is early May.

Doesn’t this make British wheat production sound boring?


Jim is on a study trip to Australia so expect further Oz-blogs over the coming weeks

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That 70s nostalgia...

Posted on 09/02/2012 by Jim Orson

I went badly off-course in last week’s blog. It started with a suggestion that I was going to discuss some aspects of the contents of the 1970 edition of Approved Products for Farmers and Growers. Perhaps this objective will be met this week.

First of all, it wasn’t a very thick book - this was still the early days of pesticide development – and there were no really effective ‘approved’ grass-weed herbicides in cereals.

Tri-allate (Avadex) had an entry, but this didn’t fit the ‘very effective’ description. I think that chlorotoluron may have been in the following year’s edition and isoproturon in the year after that.

[By the way, chlorotoluron was for a few years known as chlortoluron before the extra ‘o’ was adopted. Nobody seemed to know where the extra ‘o’ came from, but most seemed to blame the Americans. It was fashionable to blame the Americans for anything unwelcome.]Blackgrass

I actually remember the first time I saw the results of isoproturon on black-grass. It was a March application to very large black-grass plants and they were all scythed down to the ground. At that time, both chlor(o)toluron and isoproturon averaged 99% control in trials. I will pause whilst a few nostalgic tears are shed.

In my opinion, it was these two pesticides that started the revolution in wheat growing and yields. Up to their introduction, farmers on clay soils couldn’t grow winter wheat very regularly because of black-grass. Spring cropping often resulted in low yields and, with the equipment and understanding of that time, terrible soil compaction. Those farmers who tried to grow winter wheat more regularly had to resort to late drilling to avoid black-grass, which also resulted in damaged soil structure. No wonder that the UK Government commissioned a report in the late 1960s on the poor state of soils.

Just think what high levels of control of black-grass offered. Farmers on potentially high yielding clays could grow wheat more often or continuously, and soil structure improved because of earlier wheat sowing and no spring cropping.

The pace to higher yields was accelerated by the introduction of semi-dwarf varieties in the mid-1970s. These placed more of their above ground growth into grain rather than straw. Then the triazoles were introduced in the late 1970s and as yields grew so did the use of nitrogen.

The strange thing is that during the 1970s we didn’t think we were in the middle of a revolution in crop management. We came to expect new products and techniques to be produced on a regular basis. It was only when we looked back a few years later that there was a recognition of what was achieved during those few years.

The sad reality is that we seem to have about exhausted those technologies. The battle is now on maintaining their benefits from the challenges of resistance and legislation.

We now need a new fledgling technology that could be developed within the industry over time. Perhaps GM technology is currently at a similar stage of development worldwide that pesticides were in 1970. With a market, albeit initially for simple traits, it could bloom and be the foundation for the next step forward in yields. Unfortunately, the technology is being held back by a public that have been fed misconceptions peddled by those who go to bed every night with a full stomach.

Worldwide the technology is racing ahead and we have recently heard that the BASF biotech operation is being moved from Europe to the US where the technology has an immediate future.

There is much talk of the rest of the world moving ahead of Europe in the press. The anti-GM movement is perhaps just one example of a wider malaise in the EU. Many of our citizens still harbour the attitude that unwelcome technologies, such as GM, emanate from America.

Well, having got that off my chest, I realise that I have still not fully reviewed much of the content of the 1970 book of Approved Products. Perhaps I will have another go next week – as I am sitting on the plane on the way to Australia. Then again...

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