Rape yields – you decide.

I thought I’d go and look at the OSR yield data myself after listening to the spat between the wonderful Matt Shardlow of Buglife and Graeme Taylor, the Public Affairs Director of the European Crop Protection Association yesterday, and then again the umpiring of the spat by a bloke from the BBC’s More Or Less programme this morning (at the end of the programme).

Here are the UK yields (tonne/hectare) of oil seed rape running up to and including 2013, and those of cereal crops too (Defra figures: see here, Figure 6).  After 2013, the use of neonicotinoids was banned by the good old EU despite the UK’s Opatz having another view.

We can see that for the last 12 years (back to 2002) UK OSR yields have fluctuated between 3 and 4 tonnes/ha with the average being below 3.5t/ha (I’m just reading off the graph, nothing more sophisticated than that).

So, if a neonicotinoid ban affected OSR yields we would expect some low values in 2014, 2015 and 2016.  Or would we? Farmers could use neonics up until 1 December 2013 and so they would have been used on autumn sown OSR (the vast majority of the area), although not on spring-sown OSR, which would have been harvested in 2014. So 2104 was a mixed year – though closer to a ‘neonic use’ year than a ‘neonic ban’ year.

The actual yields (see here) were 3.6 t/ha (2014), 3.9 t/ha (2015) and 3.1 t/ha in 2016.

So the mixed year, 2014, was quite a good year for yield (despite some crops not benefitting from neonic use) and according to ADAS data quoted by Pesticides Action Network UK, spring sown OSR did pretty well without neonics in 2014.

2015, no neonics in use, was one of the best harvests in the past decade and a half, whereas 2016 was a poor year. It would be hard on this basis to argue that the neonic ban has had a major impact on OSR yields even though such an impact was predicted by the likes of Matt Ridley and Peter Kendall.  So Peter and the not-so-talented Viscount Ridley (who has previous, see here, here) were wrong – really very wrong. One might say almost completely wrong.  But they were predicting and we all know that is very difficult – it’s much easier to explain things after they happened than to say what will happen.

The man from the ECPA, the pesticides industry representative, was talking about a report which looks across the whole of the EU but which doesn’t seem to use actual yields but uses notional yield losses. This is very odd and a bit perverse when the actual yields are available – perhaps not for all EU countries? The data used by the ECPA report for the UK are not the available DEFRA figures for the UK as a whole (see above and references) but according to the Executive Summary of the ECPA report (page vii – go look!) this study: Alves, L.; Wynn, S.; Stopps, J. (2016): Cabbage stem flea beetle live incidence and severity monitoring. Project report no. 551. Wolverhampton: ADAS UK Ltd, which might be a wonderful study but isn’t the real information on UK OSR yields. So, Alves et al suggested that lots of damage occurred to OSR crops in 2015 but Defra figures demonstrate that this was a near-record, record-high not record-low, year for OSR yields.

And looking at the UK data, I think Matt Shardlow was right to be very firm on the point that yields have not slumped since neonics were banned in the UK. They haven’t! There has been one very good year and one quite bad year and the average yields over those two years are not lower than the average over recent preceding years.

The man from BBC More or Less didn’t do an adequate job for Farming Today. First, he seems to think that cereal yields are a guide to what might affect OSR yields and over the last 15 years or so this doesn’t look particularly true. Second, understandably perhaps, he didn’t realise that he should have counted 2014 as a neonic year (hybrid, but more neonic than not neonic) which favoured Matt’s argument (which didn’t actually need any help) and he didn’t look at any data before 2013 which was just silly of him.

Farming Today should have made a much better effort to look at the data properly and then ought to have said that Matt Shardlow should be listened to rather more than the man from the industry.

But I stand to be corrected. I’ve shown you my workings – tell me where it’s wrong.



Postscript: I certainly don’t see the industry giving Matt a hard time on social media – is that because they think he was right, or because they don’t really care about the data? Only they can say.


Website Pin Facebook Twitter Myspace Friendfeed Technorati del.icio.us Digg Google StumbleUpon Premium Responsive

Get email notifications of new blog posts

Registration confirmation will be emailed to you.

25 Replies to “Rape yields – you decide.”

  1. Well done Mark for picking up on this. I'm not up to listen to Farming Today.
    Well done Matt for being right.
    Shame on the EPCA for for producing false "science".
    It is such a shame that science reports can be abused in this manner to allow governments to use fake reports to excuse their actions.
    It is nothing new however.

  2. I'm not sure that I agree with you about the man from More or Less (another excellent programme I think). He stated:
    "It is very hard to say that this chemical ban has caused any difference at all in the yields of oil seed rape in this short period of time."
    I would totally agree with that, which is totally at odds with the €900M loss quoted by the EPCA, as if it were a hard fact. It's not, and the man from More or Less confirmed it.
    Also, looking at the graphs, the yields do seem to follow one another for some of the different crops over a long period of time, due more probably to weather than anything else, which does seem reasonable.

    1. Alex - yes but he was looking at the wrong years so he got the right answer by the wrong method.

      And you try plotting wheat yield and OSR yield (and include 2014 because one should). But he didn't do that, because he start3ed, for some reason, at 2013.

      1. Thanks for that Mark. I hope that we can also agree that Matt was correct to query the report, as I think we both suspected from the start.
        I don't suppose that your blog or the interjection from Matt will stop the UK government from resuming neonicotinoid pesticide soon, and they and th NFU will make strong reference to this ridiculous report in support of this decision.

  3. When I talked to a local farmer here about neonics he said that it is all very well banning them, but all he does is spray 5 times with something else to maintain his yields.
    Who knows whether his spray is environmentally better or worse than neonics?

    1. Dick - that is an important point and one that worries me. I don't really know what the answer to that is and it is important.

      To tackle that, one needs to know about the impacts of neonics on a range of invertebrates - lots of studies but I don't know their details at all so can't comment on which ones are good or not.

      But it's interesting that the industry chooses to put out a report on how damaging a neonic ban is on yields when the UK data seem to give it poor support. And indeed, where the UK data they use seem (to me, a sceptical brain but admittedly not a farming expert) to be rather unconvincing and an odd choice.

      If the choice is between low yields but lots of insects or high yields and few insects then that is a clear choice. But we seem to being told that neonics are both great for invertebrates and great for farmers - but we are told that mostly by the people selling them to farmers.

      It should be possible to pick away at the data and find the truth. I was tugging on one small thread here - and it seemed to unravel the story a bit.

    2. There have always been some losses of oilseed rape to insects and slugs, including when the crop had a neonic seed treatment.

      Pyrethroid sprays are the standard alternative, they are not good for bees and wildlife, but, unlike neonics, they do not persist for years in the soil, end up in the nectar and pollen of hedgerow plants, or wash into freshwater bodies at toxic levels.

      Flea beetles can cause establishment problems and during that phase farmers can spray to try to reduce beetle levels. Spraying pyrethroids 5 times has apparently happened, but is exceedingly rare. Not only is it uncommon for flea beetles to present a high risk to crop establishment, most farmers would take the hint after the second or third spraying, if these did not work they are wasting their time and money with further sprays of the same pesticide.

      It may seem counter intuitive, but neonic seed treatments can actually reduce yields. A well established cause of this is that the neonics kill the predatory insects and allow unaffected slugs to proliferate (http://www.ask-force.org/web/Bees/Douglas-Neonicotinoid-insecticide-travels-through-soil-food-chain-2015.pdf). This factor is probably why Budge et al 2015 found that in the UK oilseed rape yields were reduced by neonic seed treatments in the wettest year, and showed no overall benefit to yields (http://www.nature.com/articles/srep12574).

      This is not an unusual results, most published studies across a range of crops show little or no yield benefit from neonic seed treatments - see more in this report http://www.centerforfoodsafety.org/files/efficacy-netloss12616_38208.pdf

      Another interesting finding comes from a Natural England and Game and Wildlife Conservation Trust. They found that in Sussex 'winter cereals treated with neonicotinoids were more likely to be treated with foliar insecticides'. In other words having planted a crop with a neonic seed treatment the farmer was then more, not less, likely to spray it with an insecticide

      Back in 2012 a Bayer and Syngenta funded and promoted a study claimed that an EU neonicotinoid ban would result in significant reductions in food production costing €17 Billion and 55,000 jobs over five years, with Oilseed rape yield dropping by between 5% and 20% http://www.hffa.info/files/wp_1_13_1.pdf. In contrast the Centre for Food Safety report shows that in reality in the two years since the partial ban average EU Maize production has been 5.7% higher that the previous four years and oilseed rape has increased by 14.4%.

      The ridiculous ECPA report assumes that before the ban there were no losses of OSR and after the ban all the losses reported by farmers would have been avoided had the crops been treated. There is no baseline on OSR losses to insects and slugs (and often the exact cause of loss is misdiagnosed). This is probably the biggest of many of the flaws in their PR.

      It is also noteworthy, and contrary to the pesticide industry's doom and gloom, that the forecasters are predicting an increase in EU OSR area next year https://cereals.ahdb.org.uk/markets/market-news/2017/january/12/prospects-201718-likely-to-be-another-tight-year-for-uk-rapeseed.aspx

      The ECPA report claims that 500,000 ha of virgin wildlife habitat has been destroyed by arable conversion as a result of the ban. However, people are not going to start planting OSR out of the goodness of their hearts, the price of a cash crop has to justify the cost and with a couple of years of low prices this has not been the case.

      If the ban had reduced supply of OSR (which it hasn't) you might have expected prices to rise, but they have dropped, only this winter has the price started to recover, hence the predictions for more being planted - price is the driver, not pesticide availability.

      Thank you for the support and birthday wishes


  4. Mark et al.,

    There is some evidence, it would seem, that neonics also have a damaging effect on wild birds (see http://news.nationalgeographic.com/news/2014/07/140709-birds-insects-pesticides-insecticides-neonicotinoids-silent-spring/). It would therefore seem reasonable to postulate that neonics might also have a negative impact on spiders too, they being a significant (the most significant?) predator on invertebrate crop pests. If they are being effected by neonics, this may result in a spiraling negative impact - less natural predators, more artificial (pesticide) controls, less predators etc etc. The single piece of evidence (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4284392/) I have quickly found suggests the data is insufficient to have a robust understanding of the issue, but it is likely to be negative.


    1. Richard - there is quite a big literature on the effect of neonics on birds and other vertebrates. A good recent review is Gibbons et al. (2015), which is available free on the internet:

      Just a quick quotation: 'Consequently, ingestion of just 6 and 1.5 [neonic-treated] seeds would have a 50 % chance of killing an individual foraging partridge and sparrow, respectively. Less than a quarter of a seed could have a sub-lethal effect on a house sparrow...'
      The debate has largely been about bees, which are relatively difficult to study. The direct and indirect effects on birds have received much less publicity, but the dangers have been flagged in several independent scientific studies.

    2. Link to American Bird Conservancy report by Mineau & Palmer at this link


  5. "where it’s wrong"

    ... is that there are so many confounding variables that attempts at meaningful comparisons are pretty much a waste of time.

    OSR is afflicted by a plethora of fungal pathogens and insect pests. Varietal use changes. Weather changes. What is being claimed, any road up? Is it that OSR yield increased because neonics were banned, or in spite of the ban? Is it being suggested that neonics somehow suppress OSR yield? That isn't impossible. Was there an increased use in the ban years of organophosphate or pyrethroid use to nobble CSFB? That is entirely possible - as Dick Newell's farmer neighbour points out.

    How reliable and accurate are the yield data? No confidence intervals shown so we don't know whether year to year variations are significant or not and how valid it is to use them in determining policy? Up to a point yield is not relevant but farm-gate price is, as the profitability of OSR is a major driver for its production.

    Alves et al doesn't cover yield at all and the assessments were on crops not seed-treated with neonics, up to the 3-4 leaf stage, but did not exclude crops that were treated with pyrethroid foliar sprays to limit damage. The 1% total crop loss they report also involved slug damage so not all the losses were attributable to CSFB: 1% failed crop area was extrapolated to 6,000ha. That would be 6,000ha of cultivation and drilling and wasted seed production that must be added to the GHG emissions, with a yield of zero t.ha. Did anyone include those 6K ha of failures in the calculation of average yield? My guess would be - not.

    And then there's the knock-on effect on biodiesel production and the compensatory palm oil substitution that results. Some genius made this Law. What could possibly go wrong?

  6. I received an email from the Farmers Guardian this afternoon which carries on these nonsensical claims:

    'A recent EU report found the ban on neonicotinoid use in seed dressings has cost the industry a staggering £500 million. The impact of the ban on yield and quality of oilseed rape means increasing product is being imported from countries where no ban is in place - a deeply unfair situation'

    I'm not sure what rate of exchange (or even calculator) the FG uses but £500 million is very different to the 900 million Euro's claimed by the ECPA. I would also be very surprised if, given the weak price of Stirling if UK OSR imports have markedly increased.

    The independent agronomists (that's agronomists - not commission driven sales reps) I regularly deal with don't seem to think the ban on neonics is particularly problematic, yield loss isn't mentioned as a problem - just a slight increase in growing costs.

    Lincolnshire Rape Grower Peter Lundgren wrote an interesting blog on this very subject two years ago which debunks the myth that the alternatives to neonics are uneconomic - it's well worth a read, especially the analysis of the comparative costs: http://www.peterlundgren.co.uk/2014/01/27/is-there-a-future-without-neonicotinoids/

  7. According to the Farmers Weekly Oct 2016 "Poor weather was the key reason behind the fall in yield" of OSR referring to "the dismal yields of last summer" I think "last summer" must refer to 2016 summer if the 2015 yield was good.

  8. hard to know where to start with all these comments but will give it a go..

    Firstly yield loss is not the same as crop loss, i.e. Planted area does to equate to the harvested area and a comparison of yield per ha for each season does not show yield lost through crop failures. The areas lost in 2016 and 2015 were considerable especially in the csfb hot spots including Essex (Matt you know this but again you are choosing to ignore this AGAIN) . Secondly yield loss through csfb is not linear in that, as in most yield factors, there are multiple factors which increase or decrease yield. Csfb will severely effect the early growth stages in oilseed rape as the adults cause severe leaf damage restricting growth, this then places the plant under pressure from subsequent factors such as pigeon damage or frost lift which can cause crop failures. Thirdly adult csfb damage is only part of the picture as when the larvae hatch out in the leaf ligules they burrow into the main stem and ultimately into the tap root over the winter and spring period until they fall out, pupate and start the life cycle over again.. this larvae damage can be the worst effect of csfb causeing in extreme cases 60-80% reduction in yield. Our rape yielded less than 2tn/ha this year even though it showed very little damage in the autumn from adult grazing. The normal threshold for larvae per plant is 3-5 per stem, we were finding up to 30 per stem which was a disaster for us. However it's unlikely that neonics would have had any effect on the larvae had we used them and i spoke to agronomist who had clients the previous season who had access under derogation to neonic dressings and they confirmed this. I think the big issue was and is pyrethrum resistance in csfb combined with a run of mild winters. Needless to say we have dropped oilseed rape from our rotation and it's unlikely that we will grow it again in the near future. We were actually the first growers of rape in the U.K in seventies so big decisions for us given our cropped area.

    Whatever the causes there has been a massive reduction in the Uk rape area this autumn as farmers, especially in the Eastern counties have abandoned it. The price of rape for crushing ex farm as increased far beyond the effect caused by currency and now is approaching £370 per tn up from £230 at it's latest low point...whatever statistics you look up the market will always tell you supply versus demand.

    Getting back to the fight on Farming today it reflects the fact that farmers are under attack from greens and environmentalists on quite an unprecedented scale at the moment, some justifiable such as the neonics which are undoubtedly harmfully, through to the other end of the scale on say Roundup which is purely motivated by the anti GM lobby, backed up by some very flaky evidence that it's any way harmful, and with the potential of any ban to have catastrophic effects on U.K. Farming unlike this neonics issue which is actually a bid of a side show I hope. The worry is for farmers is it just a starter issue?

    1. Julian - thank you, as always, for your comment.

      Farmers were not attacked (even if you think you were) - the conversation was about a pesticides industry report which seemed to have little relation to government published figures. Farmers appear to want to be seen to be allied with grouse moors and the pesticides industry rather than the public and the environment. Not a very clever move in my opinion.

    2. Julian is right I believe that the Government yield figures do not account for the area of OSR that failed and were replanted with a different crop or left uncropped. However, the calculation methodology is consistent before and after the ban (2009-13 = 3.4t/ha v.s 2015-16 = 3.5t/ha). There is unfortunately no data on area of OSR lost before the ban, although we can be certain that it was not 0% as assumed by the pesticide industry reports. Even if we assumed that loss was 2% higher after the ban than before the ban (for which there is no evidence, and which is frankly unlikely) this would not be sufficient to reverse either the UK or EU data showing that OSR yields have on average been higher since the ban.

  9. "the fight on Farming today"

    Won on points without a blow being landed. The loser lost it, started shouting, went off at tangents in an effort to misdirect, and then loudly huffed and puffed into his mike. Next day you could hear the toes of the numbers bloke curling with embarrassment at having to comment on the debacle. The post-truth will out!

    Good comments on CSFB Julian

  10. Hi Mark, Not saying that farmers were attacked during the interview or that they are being attacked generally in fact there is some understanding that the industry faces some difficult challenges and that the demands placed on us are severe given societies expectations. What I am saying however that there is an attack on us from the green lobby based on ideology primarily and that issues like Neonics can become multifaceted. Buglife and Matt have a very good case on Neonics and I'd say the evidence is overwhelming but the issue becomes part of the general noise surrounding pesticides and organics with some Ngo's such as FOE, Greenpeace and the SA using them to cover their ideological agenda. As I said the Roundup issue is a case in point where these groups are determined to see it withdrawn due solely because of its links with GM which they are ideologically opposed.

    I come back to my often repeated point which is the technical agricultural knowledge base within these groups is very poor as is there engagement with food production. Often it is based on no more than a cursory extrapolation of organics with no understanding of the wider agricultural structures. Agriculture is a highly complex industry which is vertically integrated through out the supply chain; you kick out bits of that chain, be they pesticides, crops, suppliers or subsidies, at your peril and most if not all Ngo's have comprehensively misunderstood this. Neonics are a case in point; the speed of the withdrawal took the industry by surprise with absolutely no regard shown for the complexities of the supply chain. Agriculture has proved itself very capable at adapting to change, more so I would argue than most industries, and has a small (very small) pool of highly innovative and skilled mangers. I would suggest if you want change you start to listen to what they are saying ?

    Sorry I don't get that bit about farmers being allied to Grouse moors; (come on Mark not everything in life revolves round Grouse !) and actually being allied to the pesticide industry not so sure about that anymore; I think some of us privately are quite anti at the moment....

    p.s sent you an e-mail about an invitation which which might be interesting for both of us.

    1. Julian - thank you.

      I appreciate your comments but sometimes feel that our comment s to each other passeach other by, somehow. I think we probably have such different experience and ways of thinking that it's difficult to get on the same track. Probably my fault.

      For example, I took 'it reflects the fact that farmers are under attack from greens and environmentalists on quite an unprecedented scale at the moment' as farmers being attacked generally?

      Got your email and have replied - yes, please.

  11. I do wish we would call this crop something else. I can never get over the name enough to look at the data, that is just a personal... thing, with me.


Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.