It’s a small world

17 Jun 2014

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.