NIAB - National Institute of Agricultural Botany

Orson's Oracle

Moving on

Posted on 01/04/2013 by Jim Orson

We recently spent a few days clearing a house of my wife’s mother’s possessions. It was both an emotional and sobering experience. Memories and mementos of a long and eventful life were packed into a few cardboard boxes in the back of a borrowed transit van.

Whilst on the long drive back I thought that the agricultural industry has also had similar experiences over the last few decades. All those research establishments and experimental husbandry farms that have been closed down and much of what remained packed into cardboard boxes. In many ways, those who work in research establishments have to expect such change because fundamentally, change is what research is about. However, it is more complicated than that.

In my opinion change can only really be accepted if there is agreement that the current research is no longer necessary or relevant, the knowledge already gained is retained within the research community and the change reflects the most potentially beneficial direction that current research has opened up.

I was working at, rather than for, the Weed Research Organisation in 1983 when its closure was announced. Whilst having enormous sympathy for the members of staff, I admit to thinking at the time that perhaps its days were over. Established before the widespread availability of herbicides, perhaps the problems it was trying to solve had become solvable. I was also comforted by the fact that the key staff members with unique knowledge were to be transferred to other research establishments. However, this was not a true legacy as some of these disciplines have now disappeared from publicly-funded research in the UK. For instance, when I recently needed crucial information on the behaviour of herbicides in dry soils, I had to consult a specialist in Denmark.

Research budgets are tight and there are other demands on the Government’s purse so difficult decisions have to be taken. I personally agree with the emphasis on genomic research over the last few years but there is a danger of other critically important disciplines dropping by the wayside. Resistance to pesticides means that decisions to close such establishments as the Weed Research Organisation, a decision which may have seemed logical at the time, should not be viewed as the final say on a research discipline. Perhaps more academic research is now required on the behaviour of pesticides in the soil because of the challenge we face from pesticide movement to water.

People still fondly refer back to the role of ADAS during the 1970s and 1980s in transferring publicly-funded research into practice. I was an ADAS field adviser for most of those two decades and I am not so convinced about our achievements. Much of the publicly-funded research in the 1970s and 1980s was applied research, the most relevant of which could easily be adopted. That is no longer the case and so the challenges today are on a different scale.

There are different approaches to packaging and delivering knowledge. In terms of genomics, the packaging is the crop variety that is sold to the farmer. NIAB is playing a central role in packaging the knowledge gained in publically funded genomic research into breeding lines for commercial plant breeders. In the parlance, it is called pre-breeding.    In a similar vein, pesticide products are the simply adopted result of very complex privately-funded research.

It is the bits of publicly-funded and indeed industry (including levy) funded research that do not result in a product but can be used to benefit agriculture that are potentially most difficult to transfer into practice. Where the advantages are so obvious and the cost and risk of adoption is low then there is not really a problem.

The difficulty lies where there is a significant cost and/or risk of adopting something which may give less than stellar returns. In this case, it is up to those in research and its transfer to be honest and open when encountering these potential blocks to adoption rather than to moan that a couple of PowerPoint based talks have not persuaded the industry to adopt their pet project.

By its very nature, not all research is successful and the results of many projects are not at a stage that where they would lead to changes in farm decision making. However, all good relevant research that is honestly interpreted can be a stepping-stone for the industry.


Come along to the NIAB Cambridge Open Day on Tuesday 25 June to see pre-breeding research in action alongside an afternoon of seminars, indoor exhibits, and field demonstrations. Now at our new Park Farm demonstration site at Histon with expertise in plant breeding and pathology, seed testing and variety evaluation, as well as agronomic research, training and farm advice. Members-only variety demonstration tours will be available in the morning.

Three months free

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Can you take the risk of not using it?

Posted on 22/03/2013 by Jim Orson

There were a series of extremely mild winters when I was working as an ADAS field adviser in coastal Essex in the 1970s. Perhaps as a result of these weather conditions, newly emerged peas were often infested with thrips and the debate was whether or not they should be controlled. So I organised a field trial to test a range of different insecticides. Every one of the six or seven insecticides tested gave a 3% yield ‘response’; remarkably consistent results.

There was no chance that such a low response would be statistically significant, but if the differences were real then it was just about worth spraying the crop, particularly if the insecticide could be tank-mixed with a herbicide being applied at the same time. The ADAS entomologists said that as the treated yields were not statistically higher than the untreated yields there was no yield response.  The trial was repeated the following year because the results were so debatable.Cheap agchem can

The same trial the following year gave the same results, with a 3% yield response to every insecticide tested.  The discussions over the practical implications of the results led to a big falling out between me and the entomologists. My interpretation was that because every insecticide tested had consistently given a small increase in two separate years then there was a response and it might be worth farmers spraying. The entomologists stuck to their guns and said that there was no statistically significant yield response and so infested crops should not be sprayed.

The industry continues to be faced with similar statistical ‘challenges’. When is a possibly cost-effective benefit real if the response to the input is not statistically significant? This question is more likely to be asked where the cost of the input is very low relative to the monetary value of a statistically significant response.

It is a question that is now very pertinent because of the plethora of, let us call them, ‘plant tonics’ that farmers are being encouraged to buy this spring to apply to backward crops. On one hand, they can be expensive in the context of their declared contents. On the other hand, they are very cheap compared to pesticides because they have not gone through a regulatory process. And a worthwhile response from their use is way below the level of that which can be recorded as statistically significant in a trial.  For information, in wheat a yield response of 5% or more is typically required to be statistically significant.

How do we deal with this situation? Some say that the current methods of analysing experiments are not up to the job.  However, eminent statisticians have concurred that there are no alternative techniques that can be adopted to resolve this impasse.

One answer may be to modify the current statistical approach which typically sets the probability of a response being real at 95%. This means that there is a 95% probability that the response is real and a 5% probability that the response has occurred by chance. 

Perhaps these odds can be changed when the cost of the input is very low compared to the monetary value of a statistically significant response. I’m sure that, in this situation, many farmers would accept the lower odds, such as a 75% probability that the response is real and a 25% probability that the response has occurred by chance. This would reduce the size of the response required to get a significant difference. As far as I’m concerned, this is a perfectly valid approach provided that the probability of the analysis is openly declared.

In my opinion, a higher number of trials have to be carried out in situations where possible responses to cheap inputs are difficult to assess with confidence. This can then bring in the common-sense element of judging the consistency of response over a greater number of sites. 

It can also enable a cross-site analysis to be done on a greater number of sites which will improve the chances of getting a statistical difference at the more conventional probability levels. What really is not acceptable is an interpretation that involves cherry-picking the results of one or two trials where there are small cost-effective responses that may be significant at the 75% or even the 95% probability level and ignoring all the other results where there are no responses or ‘negative’ responses. As always, common sense rules.

The cost of such ‘plant tonics’ when multiplied over a few hundred hectares is not inconsiderable. So next time someone tries to sell you something on the basis that ‘it is so cheap why take the risk of not using it?’ you know what questions to ask about the evidence you need to see to be persuaded. Also, dig around for independent sources of information; there may be more around than you think.   

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Posted on 14/03/2013 by Jim Orson

I read a great quote the other day:

Insanity is a perfectly rational adjustment to an insane world
Scottish psychologist R D Laing

Quotes like these have an immediate impression if you can apply them to something you have just experienced. The fact was that I had just previously read that the Serbian Minister of Agriculture had apparently accused pro-GM groups (?) of contaminating a consignment of conventionally grown maize from his country with mycotoxins so that it failed to meet marketing standards.  

This did seem to me to mirror the insanity that is now associated with GM. Rational thought and good common sense has gone out of the window. There are now 170 million hectares of GM crops grown around the world annually and no one has caught even a sneeze from their cultivation. So if you do oppose them what do you do?  Perhaps make statements like those attributed to the Serbian Minister of Agriculture.

As he must have scientific advisers, he would have known that he was on weak ground about possible mycotoxin levels in conventionally grown maize. This may explain such a dramatic statement. GM Bt maize for the control of insect borer pests typically has lower levels of mycotoxins, in particular fumonisin and aflatoxin. This is because the fungi that cause the toxins can grow quickly along the tunnels in the maize plant caused by the borers. The sheer efficiency of control of the modified maize means that there are no, or fewer, tunnels. Not only are these mycotoxins toxic but they also inhibit the ethanol production process from maize. Hence, the ethanol production plants prefer to process Bt maize rather than conventional maize.Forage maize

There is a small part of Europe that grows Bt maize. The area of this GM crop is steadily increasing in Spain where it is grown for animal feed. I met some Spanish agronomists last year and they said that at one time the GM maize had to be segregated from conventional maize along the chain to the animal feed mills. Now, with its increasing dominance, it doesn’t have to be segregated. They also said that the feed mills prefer it because it has significantly lower levels of mycotoxins than conventionally grown maize.

I know that the so-called green groups in Spain have thrown everything, including the kitchen sink, at Bt maize. Each accusation has been patiently followed up by scientific study and found to be groundless.

In my (insane?) opinion, the history of the anti-GM movement is littered with ‘ill-judged’ statements. Some of these have been mere mischief-making and some may be the cause of avoidable human misery. The prime example of this is the apparent hatred of golden rice (genetically modified to have a high Vitamin D content) that offers so much in reducing the occurrence of blindness in hundreds of thousands of children in some parts of the world. I have written about this before but it is so important that it is worth another reference.  The anti-GM movement says that this is a cynical exercise to achieve acceptability of GMs. I have to ask who the cynical ones in this story are; those non-profit making organisations that developed it and are trying to get it introduced or those (often) multi-million pound/dollar international so-called green groups who rely on a good scare or two to keep the subscriptions coming through the letterbox?

Institutional amnesia or downright rejection of uncomfortable truths is a major concern in today’s society as the issues around Stafford Hospital clearly demonstrate. It may have always been thus. However, you must ignore everything I say: I may be completely bonkers.

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Foundation of the horsemeat scandal

Posted on 07/03/2013 by Jim Orson

Did you know that the recent horsemeat scandal was a result of the wet summer of 1845? Well, there is a link but you may find it rather tenuous.

The weather in the summer of 1845 was awful; cold and extremely wet. It all sounds horribly familiar. Not only was the weather bad in Britain but also in the rest of Northern Europe, which at that time was our main trading area for food. The Irish had their potato famine caused by blight and there were general food shortages across Europe. In Britain, the high price of food led to the repeal of the Corn Laws in 1846 and eventually opened us up to inter-continental competition.

The Corn Laws, in various forms, had been in place for centuries. The aim was to regulate movements of wheat to avoid the huge price volatility that occurred between seasons of plenty and seasons of shortage. They changed over time to adjust for improving transport systems between various parts of Britain and with Northern Europe and at one stage included storage of grain in years of plenty. So intervention stores are an old idea!Corn Laws

The Corn Laws were also open to abuse, and monarchs and parliaments tried to use them to raise money to fund their wars. From 1815 onwards they were used mainly to protect British agriculture by means of import duties. There was support for this, even from the free marketeers of the time, who thought it inconceivable that we should not be self-reliant in food production. However, the Government had to repeal them after the food shortages and high prices of 1845. As was reported at the time - “the rain rained away the Corn Laws”.

Their repeal did not have an immediate negative impact on British agriculture. A rapidly expanding non-rural population meant that prices remained relatively high and the age of science began to impact on production, particularly the use of fertilisers and machinery. In addition, the ability to mass-produce drainage tiles resulted in an enormous investment in land drainage. Between 1850 and 1880 the banks lent British farmers £12 million for land drainage, worth about £12 billion in today’s money.

However, some of the technology that aided this ‘Golden Age’ of farming presented new challenges. Steam power, which was beginning to help us to till the land, was also used in opening up the prairies. Perhaps more importantly, it resulted in faster, more efficient and more economic transport. The opening up of the prairies coupled with better transport systems resulted in a huge increase in cheap imports of wheat from the late 1870s onwards. In Britain during the 1880s wheat imports doubled and prices halved. Our high cost systems that were dependent on fertilisers to maintain fertility could not compete with large-scale farming that relied on the residual fertility from ploughing out the prairies. The so-called ‘Golden Age of English Farming’ was over and prices remained depressed until the First World War.

It was not only ‘corn’ that was down; ‘horn’ also suffered from competition. What prompted me to write this blog was that I read in The Times the other day that the first refrigerated cargo of lamb left New Zealand on the 15th February 1882, arriving in London on the 24th May. Up until then the New Zealand sheep industry had a problem.  After years of building up stock and achieving self-sufficiency their isolation meant that they had no real means to exploit their potential for lamb production. They had tried canning lamb but this was not a success. However, refrigerated steam ships provided them with an opportunity, which they took with both hands.

So, it can be argued that the wet summer of 1845 resulted in Northern European countries finally accepting that their burgeoning populations could not be fed from their own resources. In the UK the protection offered by the Corn Laws was dropped and the large scale inter-continental food trade started. And you know what that meant; complicated food chains that are obviously open to abuse. I rest my case!

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Making water wetter

Posted on 01/03/2013 by Jim Orson

When the wax finish on your car is still good, rain droplets will ‘bead-up’ and not really wet the surface as they are repelled by the wax. The impermeability of the wax on the car’s body and the surface tension in the rain droplets keep the water from ‘wetting’ the surface. Surface tension can be described as the contractive tendency of the surface of a liquid.

The same can be said for pesticides, particularly those that are water based such as glyphosate and the hormone herbicides.  Water has a higher water surface tension than the oily/waxy layers of the plant surface. Hence, it seems logical that any surfactant (surface acting agents) that reduces surface tension and so enables the spray droplet to spread will improve herbicide performance. Sadly it isn’t as simple as that.  

Reducing surface tension to as low as possible can result in droplets running off the leaf as the droplets coalesce (due to very low surface tension). Some surfactants may reduce surface tension to the point where the spray droplet is spread over such a large area that it dries too quickly, reducing uptake of an active ingredient that may need to be in the semi-liquid state to be absorbed.

So, there is a great danger in the assumption that the better the spread of droplets the better the activity of the pesticide. An additional issue is that having too much surfactant in the sprayed liquid can lead to damage to the plant surface, inhibiting herbicide uptake.

As I said last week (Have we got it?), in experiments the really big benefits of adding the surfactant ethoxylated tallow amine are only recorded at doses that are so low as to give unsatisfactory control, even after its addition. 

Research in France suggests that, even when sprayed in water that is typically marginally harder than anything we get from the tap, the benefits of adding this surfactant for the control of volunteer barley are not really apparent until the doses of the glyphosate 360 g/l formulations tested were reduced to 2.0 l/ha applied in a spray volume of 200 l/ha. The same concentration of surfactants from the formulation would be present in 1.0 l/ha product in a spray volume of 100 l/ha but crucially the actual dose/ha is still halved.

Other French research suggests that the addition of ethoxylated tallow amine surfactants to 1.0 l/ha of a 360 g/l product significantly increases spray retention when applied in a total volume of 150 l/ha.

The issue has moved on over recent years. There are some concerns over the use of ethoxylated tallow amines and many of the most recent formulations contain other surfactants. Alternative surfactants to ethoxylated tallow amine include the ethoxylated rapeseed oil surfactants.

However, some recent German, French and American research suggests that great care needs to be taken to get the right form of these surfactants. This research clearly demonstrates the danger of having a spray solution with too low a surface tension i.e. the droplets spreading too much.  

A German laboratory study identified the most biologically effective spray solution produced from mixing the unformulated glyphosate salt (the active substance) with individual ethoxylated rapeseed oil surfactants chosen from a range that differed in their impact on the surface tension of the spray droplet i.e. their level of ethoxylation. The most biologically effective surfactant was one that only marginally increased the spread of the droplet (when compared to the unformulated glyphosate salt) on easy to wet plants (e.g. chickweed and pansy) but did not increase the droplet spread on difficult to wet plants (e.g. fat-hen).   

rapeseed oil

The improved weed control resulted from minimising the glyphosate ‘footprint’ on the plant surface. This created very small but highly concentrated areas covered by glyphosate. The better biological activity may be attributed to a higher concentration gradient between the drying deposit on the outside of the plant and the xylem and phloem inside the plant.

In this German study, the droplets were applied individually and all were retained by the target plant. However, there have been field trials in France and the US which confirm that rapeseed oils with the same level of ethoxylation as those identified in the German study can be effective formulants or spray additives to some existing glyphosate formulations. The key is that the level of ethoxylation of these rapeseed oils has to be high.  The most effective ethoxylated tallow amine additives are also those with a high level of ethoxylation.

So, the assumption that the most effective pesticide formulations are those that result in the maximum spread or coverage of the plant surface is truly blown by this research on glyphosate. I’m sure that the same must apply to some other pesticides, but of course not all pesticides. It’s the same old message; no one adjuvant is a good partner to all pesticides and certainly, in some cases, at least it’s not worth making water much wetter.    

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