NIAB - National Institute of Agricultural Botany

Orson's Oracle

They think it’s all over….

Posted on 28/06/2014 by Jim Orson

Until the World Cup it has been a good footballing year for me. As a lifetime supporter of Leicester City, I was over the moon this spring because an amazing unbeaten run culminated in their promotion to the Premiership as champions of the Championship. Not only that, but I watched with a mixture of fear and excitement as the mighty U’s (for the few who do not know – Cambridge United) climbed to the top of the FA Conference Premier League at Christmas and then hung on for second place. A trip to Wembley was necessary to see them grab promotion to the Football League. This was their second Wembley appearance of the season as a few weeks previously, one of my daughters and I also watched them win the FA Vase (the equivalent to the FA Cup for non-league clubs). The photo shows them on their victory parade through the city at the end of the season.

Cambridge United victory parade 2014

Cambridge United victory parade 2014 2








Then came the World Cup; so near and yet so far. Naturally I remember the 1966 World Cup final win over Germany although I did not watch it on TV. Believe it or not, I was playing cricket for the local farmers’ team. However, we did have a radio behind each set of stumps and really lived the drama. In many ways it was perhaps a better experience than watching it on TV.

This got me thinking about how competitive we were in the world wheat yield stakes in 1966. So I looked it up and with increasing excitement found that our average yield that year of 3.86 t/ha was higher than Germany (of course!), Ireland (the current country with the highest average yields), New Zealand and France. At the last moment I thought I should check some other likely candidates and I am afraid that Denmark spoilt the story, with an average yield of 4.27 t/ha. It is sobering that their current yields are being compromised by significant nitrogen restrictions.

There is much current excitement about ‘breaking the yield ceiling’. It’s a bit like the World Cup; we spend hour upon hour planning the strategy and tactics only for the weather to prove too strong an opposition. We get so close but it is either not wet enough in the summer (e.g. 2013) or too wet and dull in the summer (e.g. 2012) for us to claim victory. Sometimes we lose in extra time. 2008 was our record year for average yields and it could have been so much better had it not been for the extremely wet harvest. That year I heard over and over again from farmers who said that they were half-way through harvesting a field when the weather broke and when they recommenced a fortnight later, the yields in the remainder of the field were a tonne/ha less.  As one Essex farmer sagely told me recently, wheat has only to look good once and that is when it is feeding into the combine i.e. it is not over until it is over.

There are some amazingly good looking wheat crops at the moment. With the right combination of sunshine and rain there could possibly be some bumper yields around. The recipe for very high yields is well known, the crop needs to intercept high levels of solar radiation and not run short of moisture. High temperatures during grain fill, particularly around and just after flowering, will reduce the yield potential.

There is a need to maintain a green wheat canopy until the end of grain fill. This is not the same as saying that a green crop canopy should be maintained for as long as possible. There is evidence in scientific literature that clearly shows that the relationship which exists between maintaining a green canopy and yield has a time limit (measured in day degrees) which is around the time of the end of grain fill.  

Extending a significant green canopy beyond that time does not further increase yields. Additionally, it does not have to be a full canopy at the end of grain fill, field experiments carried out at the University of Reading just over ten years ago suggest that by around the end of grain fill the majority of the flag leaf can be senesced and maximum yields can be achieved. Whilst I accept that such a canopy at the end of grain fill could possibly be insufficient for a record yield, it is clear that the canopy needs to be kept green but perhaps the rider ‘for as long as possible’ may be the route to some unnecessary expenditure.

It is interesting to note that whilst barley can be very different to wheat a recent HGCA project report shows that light interception by the canopy of spring barley must only be protected for approximately the first 75% of grain fill in order to maximise yield; a period of three to five weeks from 50% ear emergence depending on the site and year.  After that period, yield is insensitive to major reductions in light interception (e.g. caused by leaf diseases) probably because grain filling can be completed using dry matter from storage reserves.

So please remember, as always, do not get carried away with dogma but look at the results of field experiments and do not try to maintain the green canopy at all costs. Green is not necessarily the new gold.

Leave a comment / View comments


It’s a small world

Posted on 17/06/2014 by Jim Orson

The Cereals Event is held at a time of year when farmers look back over the season and hone plans for the coming season. This year, the change in the EU support arrangements and falling cereal prices prNIAB TAG at the Cereals Event 2014ovide much food for thought. Costs of wheat production have increased significantly over recent seasons and some farmers tell me that they now need £140-150 per tonne to break-even.

One of the reasons for the increase in costs of wheat production is pesticide resistance. Black-grass control is now very expensive with herbicide programmes often costing in excess of £140/ha in addition to the costs or income forgone that are a consequence of cultural measures. Septoria resistance has resulted in fungicide control programmes costing in excess of £100/ha. These two issues, along with the control of yellow rust, dominate many technical discussions.

I met the chief executive of a major Australian farmers’ research group at Cereals and he told me that they share the same technical challenges in wheat; herbicide resistance in grass weeds and rust and septoria control. It is indeed a small world. The last item may surprise you but the members of his group farm on the relatively wet coastal strip of Victoria. New Zealander visitors were telling me that septoria, typically less important than the rusts, has been a major problem for the last two wet seasons and that they now have, almost out of the blue, high levels of fungicide resistance.

It is interesting to read and hear that many believe that black-grass resistance is a failure of research and knowledge transfer. I agree that the issue has historically and frustratingly been under-researched. It has been obvious to weed scientists for the last two to three decades that it has always been a key issue and that the effective herbicide control required in order to support the rotations and businesses of many farmers would eventually be difficult or impossible to achieve. However, research funders could not be convinced. Perhaps, like many farmers, they believed that a new herbicide would appear and save the day.

However, we are where we are. The accusation that black-grass resistance is a failure of knowledge transfer is a little unfair. My weed research colleagues have in talks, scientific papers, press articles and leaflets, been banging on about the dangers. However, in most cases, farmers have chosen not to listen. I can understand this because we could not predict precisely the rate of development of resistance and asking farmers to forego income during hard times in the light of such uncertainty is, to say the least, challenging.

The case of Atlantis (iodosulfuron and mesosulfuron) provides a typical example of what has happened. It was introduced during the 2004 cropping season. By that time Lexus (flupyrsulfuron) and the ‘fops’ and ‘dims’ were fading fast. It was clear to weed scientists, even before it was commercially released, that resistance to it would develop quickly and warnings and label statements were issued. However, these were lean times for wheat and perhaps it is understandable that farmers over-relied on it to ensure that they could minimise the costs of production.

At Cereals there was also a strong interest in increasing yields bearing in mind the rising costs of wheat production. I have been lucky enough to have been invited to many parts of the world to observe and to speak on the subject. In particular, there tended to be a belief in many countries (with the exception of New Zealand!) that if they use inputs in the same way as we have done then they will automatically increase yields. I am afraid that typically my response to their hopes has been rather brutal; ‘it is the weather what does it’.

All we can do is to ensure that input and crop management enables the crop to make maximum use of solar energy and rainfall. In addition, in some climates cruelly cold or hot conditions can severely limit yields. It is rather naïve to believe still that there is a magic formula of input management which will dramatically increase UK wheat yields. On the other hand, we should never cease to look for marginal increases and to hope that our increasing knowledge of the genetics of wheat will lead eventually to a breakthrough.

Leave a comment / View comments


Losing flexibility

Posted on 06/06/2014 by Jim Orson

The level of risk management in arable cropping in many parts of Australia is awe-inspiring. Choosing the correct crop to grow and the level of inputs that will be required in relation to current (and future) weather conditions is critical. There are severe penalties for getting it wrong. Applying nitrogen in a dry year will reduce yields whilst there are enormous benefits from its use in a ‘wet’ year. Our decision-making over the last few decades has been by comparison straight-forward as witnessed by our relatively stable year-to-year yields.NIAB TAG Blackgrass Research Centre

However, things are changing for many UK farmers and the catalyst is black-grass resistance. No longer can herbicides be used to negate the risks involved with a totally autumn-sown rotation. This year many September sowings of wheat are severely infested with black-grass despite the huge use of herbicides. As every farmer knows, delaying sowings significantly increases the risks to crop establishment and yields.  

I gave a paper to the 1995 BCPC Brighton Conference entitled ‘crop technology; a flexible friend for the farmer and the environment’. In it I argued that the challenges of future food production whilst still protecting the environment would be best served by having technology that would give us the flexibility to manage crop production effectively. I did mention the possibility of pesticide resistance reducing this flexibility but the paper was written before the birth of another threat namely the EU Drinking Water Directive. This is putting the growing of oilseed rape at risk because the key herbicides can move to water in quantities that exceed the 0.1 parts per billion specified in the Directive.

So the question must be how do we react to the current situation? We discussed this when my colleagues in TAG Consultants visited the NIAB TAG Black-grass Research Centre last week. The bulk of the time was spent on the current difficulties in controlling black-grass and its impact on farming systems. All the alternative strategies put forward would result in a lower bottom line.NIAB TAG's John Cussans at the Blackgrass Research Centre Open Day

There are a few different approaches that may be taken but all of them must take into account the need to reduce background black-grass numbers. Lower background numbers would ensure greater flexibility because one would be further away from the cliff-edge of disaster.

Everyone is aware of the relative benefits of the different cultural control measures and the days are gone when many considered a mere tinkering with crop management was the solution. A major problem is that the full economic impact of the different approaches is almost impossible to predict accurately. There are not many heavy land farmers who have had a disaster from growing spring barley over the last few years, despite their own sometimes severe misgivings before they re-adopted the crop in order to reduce black-grass numbers. However, they may have a bad year or two in the future. On the other hand, there are many farmers who have regretted adopting later autumn sowing. One possible response to this is to choose varieties of wheat and barley that can be either late-autumn or spring sown.

A variation of this approach, straight out of the Australian ‘rule-book’, is to store home-grown undressed but tested seed of autumn and spring crops and/or varieties and to take advantage of any weather window that presents itself. Perhaps it is not necessary to look to the other side of the world for an example of this option. In parts of France farmers will grow sunflowers when the previous autumn has been too dry to establish oilseed rape.

An attractive option for many is to set out a rotation that contains sufficient spring sown crops in order that when winter wheat is grown it can be sown sufficiently early to optimise yields whilst reducing the risk of wet weather delaying or affecting the quality of establishment. The issue of winter oilseed rape is perhaps another debate; it is not easy to design an effective weed control programme that does not risk pesticide movement to water at a level that exceeds that specified by the Drinking Water Directive. Water Companies can generally deal with small exceedances but not the major peaks of concentrations that can occur.

This is the time of year to look at the level of black-grass infestations and to mull over the future. One thing is certain, there are no immediate prospects of miracle herbicides and so things will not get any easier.

Leave a comment / View comments


Ex-ministers have their say

Posted on 22/05/2014 by Jim Orson

Last week I was lucky enough to be invited to a panel discussion at the Crop Protection Association’s Annual Convention between three ex-Defra Under-Secretaries of State for Farming. It was fascinating to hear their comments now that they are largely unfettered from the responsibilities of Government.

One thing that they all agreed upon was that Defra is perhaps the government department that is most likely to have to react to issues that come ‘out of the blue’, such as animal diseases, floods and food scares. They were all concerned that the very significant cuts in the department make it less able to cope with such issues, particularly if two come along at the same time.

I suppose that the biggest unforeseen issue that Defra has had to deal with in recent years was the Foot-and-Mouth disease outbreak in 2001. Defra (then MAFF) had more resources available at that time but even then staff from its various agencies were called to the front-line. Indirectly, this prolonged the commercial availability of isoproturon in the UK. This was because the CRD (then PSD) review of the herbicide was at a critical stage when the staff involved were diverted to fight the disease. It took a few years before the review got back on track.

Another interesting aspect debated was the issue of self-sufficiency and I was delighted to find myself agreeing with the former ministers. Self-sufficiency is rather an empty term. One has only to walk around a supermarket to see the vast range of foods that we cannot economically or technically produce in this country. It reminds me of the whole life cycle analysis that was carried out a few years ago on buying out-of-season cut flowers, either shipped in from Holland or flown in from Kenya. The conclusion was that cut flowers from Holland resulted in 17 times more carbon emissions to produce and deliver to the UK customer. Repatriating that production to glasshouses in the UK would, if we were as efficient as the Dutch, close that carbon gap slightly but not by 17 fold.


I read a letter in the Farmers Weekly from Guy Smith saying that the USA is 123% self-sufficient. Again, Im not sure what this means but the geographic area of the USA and hence the different climatic zones make it easier for them to produce a wider range of foods for their citizens than we could ever achieve. For instance, in November two or three years ago, I saw the sowing and harvesting of huge areas of lettuce on the border between Arizona and Mexico. This is a winter-only activity because in the summer it is almost too hot to grow any crop successfully, particularly lettuce. The irony is that in almost every American restaurant and diner, lettuce is always served but hardly ever eaten.

We can grow some crops very competitively and the self-sufficiency argument is a distraction from us focusing on what we do and doing it even better. This does not reflect a lack of ambition but harsh economic realities. However, we should never stop looking for new and realistic opportunities such as the longer season of production that has been magnificently achieved by the UK strawberry industry. Such developments need to have a market and often require research as well as investment.

Amongst the panel there was total support for science being a key foundation in determining the future health and competitiveness of our industry. There was also recognition that science is a long-term process and not a matter of a succession of three year research contracts. However, whilst all EU governments agree that decisions should be science-based, there was a warning that political self-interest can conflict with this principle and also, that individual or small groups of MEPs can be susceptible to the pseudo-science presented by single issue groups. This raised a debate on the neonicitinoids, more on which later.

Leave a comment / View comments


50 years on

Posted on 13/05/2014 by Jim Orson

1965 was my first year at university during which I had quite an intensive course on geology. It’s a fascinating subject once you’ve remembered the sequence and dates of the different geological periods. On the course we were told about how our landscapes were formed. Over the last couple of days I’ve finally seen at first-hand a couple of the major coastal features that were used as prime examples in the lectures and which we were told we should visit. It took me 49 years to get round to seeing them! However I’m partly comforted by the fact that this, in terms of geological time, is a very rapid response.

The reason I was ‘down south’ is that I am part of a team which is trying to develop a conventional farming system in a mini-catchment that supplies a potable water pumping station. Typically, water works have carbon filters that adsorb some of the pesticides in water and also an ozone treatment in order to oxidise the remainder. Together, these two processes will significantly reduce the levels of most pesticides. However, as you may well know, metaldehyde and clopyralid (e.g. Shield SG) can survive these treatments largely unscathed. Unfortunately, at this particular pumping station they cannot treat the raw water in order to reduce pesticides. Therefore, at the input, every pesticide has to be below the Drinking Water Directive level of 0.1 parts per billion (ppb) and the total content has to be below 0.5 ppb.

Hence, there is a need to take immense care over pesticide management in this particular small catchment. There has been significant investment in farmyard facilities to ensure that where the sprayer is filled and where the pesticides and sprayer are stored are not sources of pesticides in the raw water. The next step is to ensure that pesticide use on the fields meets similar high standards.

This objective touches many farm activities; the choice of crops, the rotation, the crop protection programmes, the spraying operation, the placement of entry points to the fields and the establishment of buffer zones.

The first step has been to define which pesticides have acceptable physical/chemical properties and doses that should mean that they can be used with little concern of them exceeding their content in the water, as specified in the Drinking Water Directive. This is a very complex and challenging issue as computer modelling for each individual pesticide is impractical because of a lack of knowledge on the actual ‘leaching’ routes through the subsoil to water. An additional challenge is that there must be a readily available and cheap analysis to identify them in water at levels at or below the standards set in the Drinking Water Directive. However, we’re getting there.Drinking water

It’s clear that we cannot, at this stage, afford to have black-grass as an issue in this catchment. Its control would almost certainly mean that the standards pertaining to pesticides in water could not be met. Also, even without black-grass as a target, it is clear that robust weed control in oilseed rape is going to be at the least difficult and perhaps impossible.

It appears possible to have a robust crop protection programme in spring barley and probably in winter wheat. There are other alternative crops that might be grown but with some limitations to crop protection. A system is slowly being devised which may result in profitable conventional farming whilst meeting the Drinking Water Directive standards.

In this situation it’s easy to rely on the sulfonylurea herbicides which are used at a few g/ha. This may prove to be a short-term palliative but the threat of resistance occurring in broad-leaved weeds means that other groups of herbicides will have to be considered. There are one or two crops where only the sulfonylureas can be used. Hence, there has to be a rotational plan with non-sulfonylurea herbicides as the major means of weed control in other crops in the rotation.

The idea of the project is to start with a very precautionary approach and perhaps introduce more pesticide and cropping options if all goes well. It will be intriguing to see how this develops.

Leave a comment / View comments


Page: ‹ First  < 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 >  Last ›