Yesterday we lost the use of neonicotinoid insecticides for almost all agricultural uses in the EU. It’s been coming for quite some time, looking more and more likely since their use as a seed treatment for flowering plants was banned back in 2014. This had an immediate effect on oilseed rape growers, almost all of whom (ourselves included) used this seed treatment on just about all of our crops. The main pest we all wanted to control was Cabbage Stem Flea Beetle, a little shit of an insect which eats the small plants in the autumn, and then lays its eggs in the stem. This means that if the plant isn’t finished by September, the larvae can hatch and complete the job in the spring.

Some areas of the country are more heavily affected than others – we happen to live in one of the hot spots. The autumns of 2015 and 2016 were particularly bad for CSFB, and so to make up for the loss of neonics, everyone went around spraying foliar insecticides to try and control the problem. Now, I have written about this sort of stuff before, and I don’t intend to rehash it at the moment, but generally my feeling is that these foliar sprays are fairly useless. We don’t use them any more. What has made me write this again is hearing so many farmers taking to the internet now that neonics have been banned on all crops, not just flowering ones. That means no more Deter seed dressing for cereals, which contained a neonic designed to control aphids (which can spread a disease known as BYDV). The farmers’ refrain is predictable: “now we can’t use neonics, we will use loads more harmful foliar sprays, which aren’t targeted, so will kill everything. And our yields will suffer as we get more BYDV”.

This is almost identical to what we heard in 2014: We’ll have to use more insecticide. Yields will suffer. No one will grow OSR any more. Well, that was 4 years ago, what has happened? Let’s take a look.

Stats on how many hectares of each crop, and what they yield, is collected and published each year by DEFRA. They are freely available, and for the last few years ADAS & the AHDB have produced a nice report with all the numbers in it as well. So, I spent a little bit of time collating, and here are the results. Firstly, let’s examine the claim that fewer people would grow OSR after the ban.

Total area of OSR grown in the UK

Total area of OSR grown in the UK

That actually looks like it’s probably true. The red line shows when the ban came into effect, and 2017’s area is some 26% lower than the peak in 2012. Next, let’s look at yields.

Average OSR yield (t/ha)

Average OSR yield (t/ha)

Hmmm, OK, this one is a bit different. Far from having a negative effect, the yield in the year following the ban was higher than the year before, as was 2017. I don’t think anyone would claim the yields are consistently going to be higher, but saying they fell off a cliff is clearly wrong. They look about the same to me. [I should also mention that Thriplow Farm’s yields probably knocked about 0.5t/ha off the national average in 2016 & 2017].

Next we can move on to more detailed data. Every two years FERA carry out a pesticide survey, which shows which pesticides were used on which crops, and how often. This is interesting stuff, and it allows me to see if the prophecies from 2014 have come true. Firstly, let’s take a look at the amount of foliar insecticides used on OSR since 2012.

Average number of foliar insecticide applications on OSR per season

Average number of foliar insecticide applications on OSR per season

Here we can see that immediately after than ban, the number of foliar insecticide applications per crop did indeed go up. However, it was still lower than in 2012, when neonics were widely used. Hmmm, maybe there is still more insecticide used per tonne of OSR produced?

Total grams of foliar insecticide used per tonne of OSR produced

Total grams of foliar insecticide used per tonne of OSR produced

Uh oh! This is a killer. Again, the number has gone up a little bit since the ban was introduced, but it is still lower than in 2012.

Let’s think about this again now we see the data. Area grown has gone down. Yield has stayed similar. Foliar insecticide applications have stayed similar, as has the total amount of foliar insecticide per tonne of OSR. But, and this is critical, remember that in that time we have stopped used neonics. Looking back on it, how can anyone really say this was a bad thing? We have reduced our spend on growing the crop, reduced the amount of insecticide going into our soils, and maintained yields.

Farming has a terrible, terrible history of crying wolf. Will the same happen again when everyone stops using the other neonics next year? 100% guaranteed there will be a mega-whinge, but odds are the apocalypse, once again, will be avoided. We’ll just have to wait another 5 years to see the data.

[Below is the data in spreadsheet format]5


4 thoughts on “Paleonicotinoids

  1. Very well written, seeing the data like that was extremely useful and telling.
    I 100% agree with you.

    All the best

    W Wombwell

  2. If you live in an area where Bydv is quite a threat and spraying insecticide is tricky then deter is quite a help. You probably dont have the bydv pressure others might but we will evolve im sure!

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