NIAB - National Institute of Agricultural Botany

Orson's Oracle

Blemishes are back

Posted on 29/10/2012 by Jim Orson

It came as a real shock when my wife informed me that the local corner store was selling blemished apples. Perhaps it’s worth mentioning that our local corner store is a Waitrose supermarket and apparently they’ve done it before under the banner of fruit for jam-making.Waitrose blemished apples

However, selling blemished apples is neither a long way from, nor a long time since, when pre-packed fruit had to be without blemish and even in size. In 2009, an EU ban on fresh produce that didn’t match standard shapes and sizes was lifted. Up to that point as much as 20% of farm produce was thrown away or fed to livestock because it didn’t comply. Now pre-packed fruit and vegetables of mixed sizes are commonly on offer.

This year’s late frosts really hammered apple production in Northern Europe and it’s no wonder that more limited supplies mean less wastage by selling fruit that’s blemished. This is all a response to the new reality of more limited food supplies. One way to tackle a shortage of food is to reduce needless waste.

Surveys show that UK consumers are increasingly aware that there is a concern over future food supplies. This is a real turn-around. It wasn’t that long ago that Defra appeared to hold the view that UK food production was not that important. At the time I attended a meeting of researchers on the subject of sustainable land management. There was a significant number in the audience who thought that the last thing that our land should be used for was the production of food because it was far too environmentally damaging. They seemed to have no consideration that food has to be produced somewhere and that it would also inevitably be more damaging to the natural environment of the producing country than letting nature take its course.

There are other issues regarding the threat of food shortages. I’ve just read an article on the pros and cons of trying to bolster EU protein crop production. Much of the enthusiasm for this is based on the fact that non-GM supplies of soya are very limited. There are also strategic and food security reasons for the EU being less reliant on imported soya. The article’s author had calculated that 1.4 hectares of peas would have to be grown in Northern Europe to replace each hectare of soya beans grown in Brazil. In fact wheat produces more crude protein per hectare than peas in much of Northern Europe but of course the concentration of the protein in the harvested product is around half that of peas.

When you consider that land is one of the most limiting resources for food production this fact is of enormous significance. It supports the concept of free world trade in agricultural production where individual farmers only grow what they produce the most efficiently. In the UK we ‘do’ wheat and oilseed rape and in terms of land-use it is best to leave it to others to ‘do’ protein crops such as soya.

However, this bland statement hides other realities, such as the need for break crops. On the other hand, it seems that protein crops in Northern Europe have a long way to go to be competitive with soya, even when taking into account transport costs.

Let’s hope that R&D can deliver protein crops in Europe that can compete with soya or alternatively improve the prospects for home-produced soya. Until that time, financially inducing EU farmers through CAP to grow more crops than they can produce competitively in world markets or that are required to sustain a rotation doesn’t make much sense in the context of getting the best out of the current arable land in the world. It can only increase the possibility of more of the world’s remaining wild areas coming under the plough.

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Not a lot of people know that

Posted on 22/10/2012 by Jim Orson

You can imagine Michael Caine saying ‘not a lot of people know that’ when you hear that more sunlight hits the surface of the earth in one hour than the entire human race uses in a whole year.

Solar panels can generate electricity from solar radiation but it is intermittent and difficult to store. Only plants, algae and some bacteria have the amazing ability to capture and store the sun’s rays as sugars using photosynthesis. Unfortunately, photosynthesis is quite an inefficient process. For instance, in wheat less than 1% of the intercepted solar radiation is converted into plant material over the life of the crop. This can creep up to just over 1% during the grain fill process.

There are three photosynthetic systems - C3, C4 and CAM. The main ones are C3 and C4 with wheat and rice using C3 photosynthesis and maize and sugar cane the C4 system. The C4 system is far more efficient in converting solar radiation than C3, particularly in warm climates; for example, sugar cane can be up to 7% efficient. This means that the C4 systems also tend to be more efficient users of nitrogen and water in terms of crop produced per unit of input.Leaf stomata

So research establishments are taking the first steps in trying to convert both wheat and rice from C3 to C4. There is no guarantee that they can achieve this goal or that the C4 system in these crops will provide the expected increases in productivity. However, it is a breeding goal that is well worth investigating.

One of the reasons for the recent plateau in wheat yields is that we have exhausted many of the technologies that produced the huge steps forward in the 1970s and 1980s. There is little doubt that plant breeding offers the major opportunity to provide the much needed yield improvements.

When you look back, the technologies that can now be used to improve crop performance through plant breeding are amazing. My A-level biology studies were totally disrupted by the teacher’s enthusiasm to discuss the early findings of Crick and Watson, shortly after each paper was published. Now plant researchers are in a good position to say what traits they would like to see in a plant and identify a method to achieve that end. No longer is plant breeding based on serendipity - in just crossing specific varieties and assessing the outcome by eye.

I may be doing pesticide discovery a disservice by saying that they still rely on serendipity by just testing a range of chemicals and seeing if they work. I realise that it has become more sophisticated over recent years with high throughput screening. However, I have yet to hear of a pesticide that has been discovered using the reverse process of getting an end point and working back to a pesticide that will achieve the result required.

Plant researchers are entering into new areas of opportunity. They now have the tools to design and make complicated biological molecules. The discipline is called synthetic biology and offers great opportunities. For instance they are trying to create an artificial system to mirror photosynthesis by stripping it back to a level of basic reactions where much higher levels of energy conversion are possible. In a world concerned about the implications of the current reliance on fossil fuels, the rewards for such an achievement would be huge.

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Posted on 15/10/2012 by Jim Orson

As you may have heard, NIAB TAG have set up a task-force to investigate the 2012 yield performance issues in winter wheat, with the aim of understanding and explaining the drop in yield across much of the country as well as significant local yield variations.

I was doing a bit of background work for the task-force when I realised that I’d made a bit of a misjudgment in a previous blog (Exceptional! 6 August 2012). I commented on the output of a model at Rothamsted Research. For their farm the major loss of nitrogen in winter wheat during this year’s exceptionally wet late spring and early summer was due to denitrification and not leaching. The model also showed that the roots of the crop during this period were largely starved of air due to waterlogging and it was this aspect that I rather brushed aside in my blog. However, this issue may have had a large impact on yields this year.

So, a couple of weeks ago I found myself in the library in Rothamsted looking up references on the impact of timing of waterlogging on wheat yields. There aren’t many studies on the impact of waterlogging during stem extension and grain fill of wheat and some of these have been done in very large containers (lysimeters) rather than in field trials.

Rothamsted LibraryHowever, they all show the same thing...

The conclusion, based on my reading of the literature, is that waterlogging alone in May and June this year must have had a significant impact on yield. As a rough guide, one day’s waterlogging in mid-May has the same impact on yield as five days waterlogging in the winter. Waterlogging during grain fill can reduce grain set and reduce grain size.

So this must be part of the explanation to the variation in yields we saw this year. There are other aspects that also need to be considered and these are being tackled by the task-force.

It was the visit to the Rothamsted library that also highlighted how the communication of science is changing. There were stacks and stacks of books and a lot of desks on which to read them but I was the only person there. The reason is that scientists now access and read papers on-line.

This will also change in the near future. Publishers have been charging non-subscribers to scientific periodicals a fairly substantial fee to access a single paper. There are now firm proposals that there should be open access in 2014 to all papers based on scientific research funded by the British taxpayer. There are similar proposals throughout Europe. This will inevitably impact on learned societies, some of which generate as much as 90% of their income from publishing papers in their periodicals. They are being offered alternative funding arrangements to peer review papers. I hope that these proposals will be realistic and allow them to continue.

These learned societies provide a structure to science and facilitate like-minded scientists to get together and debate relevant issues in an academic setting. Let us hope that the move to open access of the papers that these societies publish (a move which I wholeheartedly support) does not reduce their effectiveness in sharing and advancing knowledge.

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Is arable farming going to hit the buffers?

Posted on 04/10/2012 by Jim Orson

We now have a few new registrations coming through that have been completed since the HSE’s Chemicals Regulation Directorate (CRD) introduced its interim arrangements on assessing aquatic buffer zones.

The new product Teridox (dimethachlor) has a buffer zone requirement of 10-metres and the new Hurricane (diflufenican) labels will have a buffer zone requirement of 12-metres. Dow claims that Dursban (chlorpyrifos) would require a 72-metre buffer zone according to the method of assessment that’s being used under the interim measures. Under the interim arrangements buffer zones wider than 5-metres cannot be reduced under any circumstances, but they are only necessary when there is water in the ditch.

These are worrying buffer zone widths and all kinds of issues arise from this situation.

First of all, are the new widths based on good science? I know that the basic drift model used to develop the original LERAPs scheme was based on a narrow boom width sprayer travelling slowly. Drift from sprayers travelling at 12-14 kph is undoubtedly higher. So there may be some logic in the wider buffer zones from that point of view. But the question has to be, has something been identified that suggests that current buffer zones and application techniques are causing a problem?

The only information I can find on the likely scale of any problem is dated 2010 and says that only 1% of surface water bodies monitored by The Environment Agency are failing their Environmental Quality Standards for pesticides. This is a low level of failure, but of course any failure has to be regretted. However, a failure may have been due to pesticides moving to water through the soil or on the soil surface rather than spray drift.

Buffer stripsMonitored water-bodies tend to be lakes and rivers and not small ditches on farms. So the question is whether farm ditches, which may have water in them from time to time during the year, contain a viable aquatic ecosystem that requires an aquatic buffer zone to protect them? The French authorities appear to be of the opinion that this is only seen with larger on-farm streams and water-bodies.

The other issue is whether mitigation will eventually be introduced so that these newly introduced buffer zones that are wider than 5-metres can be reduced in the future. Let us hope so. The great thing about the original LERAPs scheme was that it rewarded good practice by allowing a reduction in buffer zone width due to the adoption of lower doses and/or reduced drift spraying techniques. This resulted in many farmers using the lower drift air induction nozzles for nearly all spraying operations and there are now other engineering solutions that could further reduce drift, including improved control of boom height. Let us hope that good practice will eventually be rewarded when the arrangements are finalised.

There are other mitigation methods that also need to be investigated. Drift studies are carried out where there is very short vegetation, but there is some evidence that taller vegetation in the buffer will trap a very significant amount of drift. This also offers the opportunity for a bit of joined-up thinking because such vegetation, correctly managed, may also be a large step forward for biodiversity.

Some farmers think that one way forward would be to use adjuvants to reduce drift. This is a minefield as an adjuvant may reduce the drift for one product but may increase it for another; the ultimate minefield would be when tank-mixes are used.

The graph shows the impact on land availability for food production of wider buffer zones. Paradoxically, it is those farmers who have ‘done the right thing’ for biodiversity who are the ones that will be most penalised because they haven’t created large fields by ‘piping-in’ ditches and removing hedges.Impact of buffer zones on arable land availability

I recognise that this is the worst case scenario because I’ve assumed a buffer zone on every side of the field but you get the ‘drift’ (sorry about the pun). It is sobering fact to mention that our high yields mean that for every hectare of cereals not produced in this country a few hectares will have to be grown elsewhere in the world. It is beholden on us not to export environmental impacts to other countries.

There are other implications as well. Farmers, where they can, will avoid those products with wide buffer zones, and not just on the fields that have ditches that may have water in them at the time of application. This is because of the way that arable farming now has to work - spray operations are pre-planned and appropriate to not just one but a number of fields. Hence, there could be more reliance on fewer modes of action and an increase in the risk of pesticide resistance.

So, there’s a lot to play for and we look to the regulators to consult widely and to develop a simple but scientifically robust solution that meets the concerns of the farmer and the conservationist as well as the consumer who is reeling from higher food prices.

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A non-event

Posted on 28/09/2012 by Jim Orson

Last week something did not happen. Let me explain what I’m talking about and why it’s heartening news.

In the middle of last week I suddenly started to receive emails suggesting that there was going to be a major announcement the following morning on a refereed paper that suggested that rats fed on GM maize were more likely to develop tumours than those fed on conventional maize.

The press conference was timed in order that it could feature on the lunchtime news broadcasts. So the next day I sat down to listen to the lunchtime news and there was no mention of the paper. Similarly, there was no mention in the evening broadcasts. The next day this refereed paper was only given some credence in the Daily Mail, but not so on their website.

Now if this scientific paper was published a few years ago there would be widespread coverage in the press about the dangers of GM. So why didn’t it get the coverage last week? There may be a few reasons, including a changing press and public opinion on GM. However, there is also, in my opinion, a gradual recuperation in the reputation of and respect for good science.

In March 1996, the British Health Minister announced that a committee of scientists set up to advise the government on spongiform encephalopathy issues had linked an unusual outbreak of a human degenerative neurological disease to BSE. The politicians had said that such a link was impossible. They stated that this was based on scientific opinion but of course no scientist had said categorically that this could not occur. So science and scientists, unjustifiably, got it in the neck both from the media and the general public. There then followed a long period when there was a high level of distrust of scientists, something that was latched upon by the anti-GM movement.

The start of the recovery of the reputation of science was, in my opinion, as a result of the Lancet article in 1998 in which Andrew Wakefield claimed that there was a link between the MMR vaccine and autism. These findings were based on unsound evidence and in 2004, fellow authors of the Lancet article issued a retraction. In-between the two dates there was considerable media support of Wakefield. He was seen by the press to be a whistle-blower standing up to the state machine. However, in 2010 the General Medical Council concluded after a two and a half year hearing that Wakefield had acted unethically, dishonestly and irresponsibly. Shortly afterwards the Lancet fully retracted the article from its online version.

Science reporters now deeply regret their coverage of the MMR issue and seek to listen to other views before jumping to lurid headlines. This is what happened last week. At the news conference reporters even quoted the comments and concerns of other scientists on the paper. Their access to other views did not occur by chance but through the good offices of the Science Media Centre who circulated the paper, at very short notice, before the press conference to the relevant scientists for theirinformation and comments. It turns out that there were real concerns about the science and these were expressed at the press conference and were obviously not well defended by the speakers. Subsequently, the French author of the paper has refused to release the raw data of the study to the European Food Standards Agency, which is not a position that instils confidence in his findings.

So I think science is now in a much healthier place than a few years ago when any bit of questionable science could unjustifiably grab the headlines. The press conference was arranged by a leading figure in the anti-GM movement and now perhaps that movement will have to accept that questionable science does not lead to a progression in public debate. It only devalues their reputation. Many thanks to the Science Media Centre for ensuring such a balanced debate.

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