NIAB - National Institute of Agricultural Botany

Orson's Oracle

Hazard – EU decision making

Posted on 04/12/2014 by Jim Orson


SprayerThe Pope has had a little dig at the EU institutions suggesting that they have lost their way and that they view the member states “with aloofness, mistrust and even, at times, suspicion.” Pretty tough talk and perhaps the Pope is the only person who could proffer such an opinion without a huge backlash from the bureaucrats in Brussels and Strasbourg. 

I suspect that many in the pesticide industry would endorse the Pope’s analysis. Increasingly, legislation appears to be determined by mistrust and aloofness and has resulted in some key decision-making on pesticides and GMs not being based on science. Perhaps this is best demonstrated by the green blob’s coup of lobbying for the post of EC Chief Scientist to be discontinued. Sure enough, within a month or two Ann Glover was sacked. Could it be that the reason for their hostility was that she supported GMs? Her support was derived from hard evidence and good science. The green blob, knowing that any successor to the post would also be a scientist who would rely on the same sound principles, decided that the post rather than the current incumbent should go. 

The new pesticide legislation will result in active substances being banned solely because they are defined as hazardous. This is a departure from the previous science-based practice where the risk of using a potentially hazardous substance was assessed. This approach was based on the principle that it is only the level of exposure to a hazardous substance that defines the level of risk. Just to give an example of the difference between a risk and a hazard: electricity is hazardous but the risk of using it is very low because we are not directly exposed to it. 

We may lose a lot of pesticides (e.g. the triazole fungicides) because they could be characterised as hazardous as they may be defined as potential endocrine disruptors i.e. they disrupt the hormone systems of animals. Those who support the hazard cut-off for endocrine disruption quote the increase in endocrine diseases (primarily diabetes) in humans and the feminisation of male fish. The link with diabetes seems to have been made with pesticides long banned in Europe and used particularly in parts of the world where pesticides are less regulated ( However, as the definition of what may be an endocrine disruptor has yet to be agreed, it is impossible to assess precisely the likely extent of the damage to the agricultural industry from this hazard based approach. 

I have been taking an interest in the potential level of exposure of humans and wildlife to those pesticides that may be defined as endocrine disruptors. One potential source of endocrine disruptors to humans (and fish!) is surface and ground water. However, less than a handful of those pesticides that may be defined as endocrine disruptors have been found in water in the UK and then at incredibly low levels. A recent Defra pamphlet stated that “research has found small amounts of endocrine disruptors in some of our rivers. However they tend to occur only in immediate proximity to industrial and wastewater discharges” ( I accept that pesticides were probably not counted as endocrine disruptors in this survey but it is important to state that there are other sources of such chemicals. 

The other significant source for humans ingesting endocrine disruptors is through food. However, the surveys of wheat flour carried out under the auspices of the Defra Expert Committee of Pesticide Residues in Food and the European Food Standards Agency have, with one or two exceptions (which were typically well below Maximum Residue Levels), failed to detect traces of those cereal pesticides that may be defined as endocrine disruptors. 

Another potential threat could be to spray operators but, as far as I am aware, surveys on their health have not picked up any problems that can be associated with endocrine disruption except where there has been prolonged exposure to pesticides that were banned in Europe many years ago. Finally, exposure of bystanders to spray drift is a hot topic. I am not sufficiently briefed to comment on the level of risk from this source but the adoption of air induction nozzles and good spray practice should minimise any risk. 

I have come to the conclusion from this rather simplistic analysis that the exposure of humans and animals to those pesticides that may be defined as endocrine disruptors could be negligible or extremely limited. Hence, it seems incredible to me that they may be banned as a matter of course. It is worth noting at this point that some foodstuffs naturally contain potential endocrine disruptors, such as the phyto-oestrogens in soya bean products, the fibre of whole grains, vegetables and flax seed ( 

The European Commission is running a consultation exercise Endocrine Disruption Legislation ( It is essential that farmers and their representatives respond to the consultation and state the likely effect on the yield and quality of the crops grown, the impact on pesticide resistance management, the fact that there is a lack of alternative control methods in some cases, as well as what this means to their businesses. Those not close to the industry will be unaware that it takes only small changes in cropping and/or a reduction in yield to have a devastating impact on the finances of a farm business. A report by Anderson’s for the NFU, AIC and CPA provides much of the background information required ( I think that it is also important to ask if there is a credible reason (i.e. not just the unrealistic invocation of the precautionary principle) to suspect that the pesticides that may be listed as endocrine disruptors are a threat to human health and the environment. The green blob considers that numbers count in terms of response to consultations and so too should the industry.

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How to make money

Posted on 20/11/2014 by Jim Orson

In recent years I have pondered that the easiest way to make money must be to rent a shop in Cambridge and populateCup of coffee it with a few tables and chairs and serve good quality coffee. Pricing a cup of coffee would not be a problem; just think of a ridiculous amount and then treble it would be about right. Even better, have a few tables and chairs outside and there will not be a spare seat whatever the weather.

However, this get rich quick scheme may not be as robust as I thought. There has been a recent report that says that individually owned coffee shops are struggling.

Never mind, I now have a new plan which developed as I walked around the pesticide section of the local garden centre. There are now precious few active ingredients available to gardeners and, partly as a consequence, there is a growing range of ‘natural alternative’ pesticides. I noted one natural insecticide sold in 200 ml bottles. It comprised 160 ml of oilseed rape oil and the remainder, I assume, was an emulsifier in order to keep the oil in solution whilst it is being sprayed. The price was £6.99! Yes, £6.99! That must be the way to make money.

I first heard of oils (in this case mineral oils) being used as insecticides whilst talking a few years back to a French farmer. He was spraying his potato seed crop regularly with them in order to reduce/prevent aphids feeding and spreading virus. This has an advantage over conventional insecticides which tend to kill aphids after they have fed on the plant and consequently have already spread the virus. A report for the British Potato Council endorses the potential for this approach, possibly in combination with conventional insecticides, and now field research is being done to measure the benefits of using oils in order to reduce/prevent the spread of viruses.

Sorry, I have strayed from my theme of making money. It seems at the moment that producing commodity crops is not a way of making money as there is no shortage of supply because of good levels of world production this year. This is a recurring story in our industry. Uniquely there are a countless number of producers in the world whose yields can be profoundly determined by the weather resulting in it being impossible to finely balance supply and demand. So, it is perhaps in everyone’s interest that farmers will continue to produce food even when there is the distinct possibility that they will produce too much, resulting in them losing money. Some say that this is the reason why we need subsidies in order to ensure that, if anything, the world has over- rather than under-production of food.

I realise that some countries do not receive subsidies. New Zealand is an example but their commodity crop production is relatively minor in world terms and they have many alternative cropping opportunities. I am the first to admit that they themselves have created many of these alternative opportunities, such as specialist seed production, and that this may not have occurred had they received subsidies. On the other hand, there is a limited area needed in the world for such specialist crops.

Perhaps subsidies should not generally be viewed as wrong provided that they help to reduce significantly the number of years when there is an insufficient supply of the major commodity crops. The last time there was a price spike because of concern of under-supply, it caused food riots particularly in some poorer parts of the world. However, I would rather be part of an industry that does not require subsidies but this may be unrealistic until world production consistently struggles to meet demand.

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The fuel that refuses to peak

Posted on 13/11/2014 by Jim Orson

The preparations for the wedding were amazingly thorough. We believed that we had thought of every eventuality but I had not thought of the conversation I would have with my youngest daughter on the way to the Church. She was cool and collected and so I did not have to ward off last minute doubts or nerves. So I heard myself say as we passed the nearest petrol station “diesel has gone down 5p a litre this week”. To give my daughter credit, she did not react to this, in the circumstances, rather crass comment! 

That was in 2008 during the height of the financial crisis when the oil price suddenly collapsed. It is now falling again, this time at a steady rate. Diesel prices are now back at wedding day levels. 

A couple or so years before 2008 the green blob was making a great thing about peak oil production and that supplies would soon start to run down. This they argued would mean that the price of nitrogen would inevitably become so high that conventional farming would collapse. I assume that they were aware that this could have disastrous consequences. An adviser to the President of the USA had previously stated that a world without nitrogen fertiliser could sustain a human population of no more than 5 billion. It is now at 7 billion. 

I am not sure why the green blob associated the oil price with the cost of nitrogen. True enough, making nitrogen depends on energy but it can come from any source, oil, gas or (sustainably as well as unsustainably generated) electricity. In fact the first time the Haber-Bosch process was used to produce ‘artificial’ nitrogen it was fuelled by electricity. 

One of the causes of the recent fall in oil prices is fracking in the USA. It has distorted all the previous projections on oil production. Apparently we have good reserves that could be fracked but of course the green blob is instinctively against this. Media coverage has indicated that rather oddly, the main ‘evidence’ they quote against it has been largely generated and promulgated by the oil rich nations who have something to fear from the technique. Also, the NIMBY vote is on their side. During the demonstrations at Balcombe in East Sussex there were placards saying that 82% of the residents were against fracking. I am sure that the same 82% would also be against a wind farm or a solar energy park within their parish boundary. 

I find the green blob’s view on what is considered good evidence intriguing. They constantly criticise politicians for ignoring the “overwhelming evidence” that climate change is occurring but with breathtaking hypocrisy ignore the overwhelming evidence that the currently registered GMs are not harmful and that the technology offers unique future options for crops that will benefit society and the environment. The hypocrisy does not stop there. They now acknowledge that there are vast areas of the world covered by GMs but state that the technology has not delivered what it promised.  We all know why this may be; the unreasonable and ill-informed opposition that has hindered or halted the development of this technology in many parts of the world. 

There is one area where I am on the side of the green blob. Much of their concern is about the companies who own the GM traits having too much influence over the food supply chain. However, that is not the fault of the technology but a challenge to legislators.

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Hard to believe

Posted on 05/11/2014 by Jim Orson

I’m not fond of museums, but I am a nightmare when I actually visit one. I read everything and so make very slow progress. I remember my family hauling me out of the Elvis Presley museum in Las Vegas because I had barely progressed beyond about 20% of the exhibits whilst they had done the whole lot and had had a cup of coffee.

The same slow progress occurred a few days ago. We were invited to a ‘do’ just down the road at the Imperial War Museum at Duxford and were given the freedom to see the exhibits for most of the day. Needless to say, I went round just one of the many hangars. In this there was one of the two prototypes of Concorde. It seems that it did its cold weather testing above the Equator. This really sounded counter-intuitive so I read on. Apparently the coldest temperatures at 50,000 feet are above the Equator and the warmest temperatures at that height are above the North Pole!

Issues that have occurred in my day job have sometimes sounded counter-intuitive but again have been true. The prime example was when NIAB TAG, in its most recent 60 trials, collated the nitrogen response curves for feed wheat and found that the economic optimum nitrogen doses did not appear to decrease with increasing Soil Mineral Nitrogen (SMN) levels in the soil. In fact, the best predictor of the optimum dose for the yield of feed wheat in individual trials was to apply the average optimum dose identified in the 60 trials rather than follow any of the current recommendation systems.

I must admit that this worried my colleagues and I because it seemed cFertiliser spreadingounter-intuitive and so we read published papers which contained the results of similar trials. True enough, the overall conclusions were the same for situations similar to those in our trials. Interestingly, this also included the database used for the current edition of RB209.  It should be noted that all our trials were done on long-term arable soils where there had been no recent history of organic manure use; we did not have sites on true sands or the true silts. None of our sites had SMN levels above 100 kg N/ha. Please note that I am talking about feed wheats where the level of protein is immaterial.

Our results have been a continuing fascination to me. Subsequently, I developed an alternative recommendation system and tested it against the results of our trials and also the trials carried out by other organisations. It gave almost the same level of accuracy of prediction for the optimum dose in each trial as applying the average dose identified in our database.

The alternative recommendation system I developed was not very novel because it was the same as that used in RB209 except that SMN was assumed to be used at 50% efficiency rather than the assumption of 100% as used in RB209. This simply resulted in the recommended N dose being reduced by 15 kg/ha between index 1 and 2 and also between 2 and 3 rather than the 30 kg/ha in RB209. There is now so much information to suggest that the efficiency of use of SMN is well below 100% that this evidence can no longer be ignored in the next edition of RB209.

Recently we have re-opened an internal email debate on our results and discussed them with a soil scientist who has penned many peer-reviewed papers on nitrogen application to wheat. This correspondence released the genie of canopy management.

Remember, canopy management in wheat? It was the vogue for many years and much research funding was spent on it. It argued that wheat yield was not related to nitrogen dose but was determined by using the nutrient to build an optimum crop canopy to trap solar energy efficiently. I think it failed because the SMN was assumed to be used at 100% efficiency and because by the time the size of the final dose of N could be calculated, it was often too late in the season for it to be fully exploited by the crop.

Let’s go through the maths of canopy management but assume that SMN is used at 50% rather than 100% efficiency:

  • To trap sunlight efficiently in wheat there needs to be a Green Area Index (ratio of the green surface area of the crop per m2 to one m2 of soil surface) of at least 6 by around ear emergence;
  • Each unit of GAI requires around 30 kg N so the total of N required in the crop by around ear emergence is 180 kg N/ha;
  • There is already some N in the crop by the spring, typically around 30 kg N/ha;
  • There is also some in the soil (SMN), typically around 50 kg N/ha which we now assume is used at 50% efficiency by the crop;
  • This means the N demand to be met by applied bag N is 180 kg N/ha less the 30 kg N/ha already in the crop and the 25 kg N/ha from the soil;
  • Therefore the demand for N from the fertiliser is 125 kg N/ha;
  • RB209 assumes that bag N is used at 60% efficiency and so the dose needed to satisfy the crop requirement of 125 kg N/ha is that number divided by 0.6;
  • This equates to a dose of applied bag N of 208 kg/ha.  

This is extraordinarily close to the average economic optimum dose of 205 kg N/ha in our 60 trials when one kg of N costs the same as 5 kg of wheat. The optimum dose of bag N increases as the price of N gets relatively cheaper. This demonstrates that achieving a more complete canopy, either earlier in the season and/or during grain fill, is worthwhile when the cost of N falls relative to the price of feed wheat.

I recognise that I’ve ignored N from rainfall and from net mineralisation in this calculation. Much of the rainfall that is received by the crop occurs by the early spring (when N availability in the soil and crop is assessed) and net mineralisation is limited in the situation of our trials. In the context of our trials, these are relatively background constants and so do not affect the level of reduction in N recommended between indices 1 and 2 and between indices 2 and 3.

It is comforting that canopy management for a typical situation suggests the same optimum dose as the average of our 60 trials. However, some soil scientists maintain that canopy management should not be considered when predicting the optimum N dose of very high yielding crops. They assume that as yields rise, grain N (protein) gets diluted and there must be a limit to this dilution. All I can say is that our trials have shown that doses of around 205 kg N/ha can support surprisingly high yields of wheat. In fact, our results intimate that only a very slight upward adjustment of N dose is needed for yields of feed wheat above 10–11 t/ha. This is because although the N removed from the field in very high yielding feed wheat can be higher, such crops are much more efficient in taking up and utilising nitrogen than average yielding crops.

I’m sure that there must be logical reasons for the temperatures at 50,000 feet to be at their lowest above the equator. Not to be outdone, we’re slowly developing a better understanding of what drives the optimal doses of N for feed wheat. Whilst this results in the improved predictability of the ‘average’ situation, our database suggests that there is a large and unpredictable variation between sites in the efficiency of use of both SMN and applied nitrogen. Trying to establish reasons for such a variation remains a significant challenge to researchers.      

Please remember that milling wheats are a different kettle of fish because additional nitrogen, above that required for yield, is necessary in order to meet the specified grain N (protein) content for higher yielding crops.

Apologies for the length of this blog being as tortuous as my progress round Duxford....

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Precautionary principle cuts both ways

Posted on 17/10/2014 by Jim Orson

I had a flu jab recently. The vaccine is to protect against the strains of flu mostly likely to occur this coming winter. It got me thinking about the long standing debate over the last few decades about prophylactic versus rational decision-making for pesticide use. Nobody now supports prophylaxis, but there is an issue regarding the definition of rational and responsible decision-making.Flu jab

About fifteen years ago, a Government Committee on Pesticides visited Morley Farm, the home of NIAB TAG in Norfolk. I described the approach to pesticide use on the farm and mayhem literally broke out when I described weed control in sugar beet. The adopted FAR approach meant that every week, for at least three weeks after crop emergence, the crop was sprayed with a tank-mix of herbicides, all at very low doses. Weeds typically had a maximum size of not much bigger than early cotyledon when they were sprayed. After three applications the intensity of treatment was eased according to observations on weed emergence.

The committee was horrified by such an approach because there was no opportunity for us to identify both the species and number of weeds emerging in order that we could take a more ‘rational’ decision on whether or not to spray. This, they claimed, was an essential requirement for responsible pesticide use. I tried and tried to get them to realise that all our trials had shown that, overall, FAR involved significantly lower levels of herbicide use than in the more conventional programmes but their minds were closed. My horror of such an attitude was further reinforced a few months later when at a conference I gave a paper mentioning the FAR approach and the level of pesticide savings involved. In the audience a high ranking scientist in MAFF was vehemently shaking his head in disagreement.

Hence, at around the turn of the millennium it was obvious that in official circles, rational decision-making necessarily involved thresholds. This was despite a large multi-site field trial project in the 1990s investigating the role of weed thresholds for broad-leaved weed control in winter cereals. The results showed that the annual use of lower-than-recommended doses of herbicides used less herbicide over time than the use of thresholds to decide whether or not to treat. In addition, there were high costs associated with doing the necessary field surveys to assess weed numbers for the threshold approach. On a more theoretical level, modellers had also reached the same conclusion for wild-oat control.Sugar beet

It’s now clear to all in the industry that thresholds (including those based on forecasting) are not the universal approach to rational decision-making on pesticide use. This may be because once a threshold has been exceeded, effective and timely control may not be achieved, either because of weaknesses in the pesticides to be employed or because of weather delays. The FAR approach initially seemed wrong to many but was the right solution bearing in mind the limitation of the selective herbicides available.

Very effective pesticides will increase the prospect of thresholds being adopted.  For instance, those who prefer a situation where weed numbers and species are assessed before making a herbicide application in sugar beet should really be on the side of GM glyphosate tolerant beet which currently offers the only hope for the practical adoption of such an approach.

The precautionary principle is clearly behind the widespread inoculation against flu. By the time an epidemic has started and the specific strain identified it is too late to make the vaccine and inoculate the most vulnerable. Those who argue against the registration of some pesticides and GM crops also invoke the precautionary principle to support their arguments. However, the very same people fail to see that farmers may also have to invoke the precautionary principle rather than thresholds when taking carefully assessed risk-based decisions on pesticide use.

The important thing to bear in mind is that there are various approaches that farmers must take when assessing the need for pesticide application. Thresholds are the right approach in some circumstances, particularly for insecticide application. In others, thresholds are both impractical and unwise and alternative precautionary, but risk-based strategies have to be adopted. Unfortunately, such risk assessments are now heavily influenced by the reality of pesticide resistance which results in farmers having to take a more precautionary approach. It should be noted that risk assessments are also necessary for the applicability of adopting cultural measures that may reduce a farm’s reliance on pesticides.

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