Efforts to prevent a Himalayan crop disease from running rampant through East Anglia's wheat fields was among the issues discussed by researchers at a farm open day.

Eastern Daily Press: NIAB open day at Morley Farms. Bill Clark, technical director at NIAB. Picture : ANTONY KELLYNIAB open day at Morley Farms. Bill Clark, technical director at NIAB. Picture : ANTONY KELLY (Image: archant 2017)

The event run by NIAB (National Institute of Agricultural Botany) was hosted by Morley Farms near Wymondham, where strips of different wheats have been treated with different fungicide regimes to show visitors how each one performs under typical Norfolk conditions.

By comparison, some untreated plots had become infected with brown rust, a particular problem in East Anglia this year because it thrives in dry, hot conditions.

But Bill Clark, technical director of NIAB, based in Cambridge, said the bigger problem was a yield-killing strain of yellow rust, which had left scientists baffled as to how it could have arrived in Europe from its origins in Asia.

'We have genetically finger-printed this yellow rust, and we know it comes from the Himalayas,' he said. 'But we don't know how it got here. 'Normally these diseases are transferred after they are picked up on people's trousers as they walk through a field and then get on a plane, but we know this didn't come on an aeroplane, as it all came into Europe all at the same time.

Eastern Daily Press: NIAB open day at Morley Farms. Bill Clark, technical director at NIAB. Picture : ANTONY KELLYNIAB open day at Morley Farms. Bill Clark, technical director at NIAB. Picture : ANTONY KELLY (Image: archant 2017)

'You know we can sometimes get Saharan dust storms, but if these spores get into the high atmosphere they would be killed, so it is not spread on the jet stream.

'The reason it is important is that plant breeders have been breeding varieties that are resistant to European rust for the last 20 years, and suddenly there is a new population of rust comes in and two-thirds of a our varieties are susceptible to this. If it is not treated, you will lose half your yield.'

Mr Clark said the appearance of new crop diseases was an extra complication in the battle to increase crop yields without over-reliance on herbicides and pesticides – particularly with many chemicals under threat of EU bans.

'All of this is about food production,' he said. 'It is about producing high yields, but non-farming people always ask why people use all these pesticides.

Eastern Daily Press: NIAB open day at Morley Farms. Bill Clark, technical director at NIAB. Picture : ANTONY KELLYNIAB open day at Morley Farms. Bill Clark, technical director at NIAB. Picture : ANTONY KELLY (Image: archant 2017)

'Some of the high-yielding varieties we have here get a lot of disease and without the crop protection they would lose half of their yield.

'So the farmer is trying to protect the yield potential of this crop, and today is about finding the optimal way of doing that – how little they can spend while still getting the yield. It can sometimes appear easier for them to spend more on fungicides, but this is about managing their risk.'

IDENTIFYING BROME WEEDS

The NIAB Morley Open Day also gave farmers a chance to learn about how to identify and tackle brome weeds.

Eastern Daily Press: NIAB open day at Morley Farms. Bill Clark, technical director at NIAB. Picture : ANTONY KELLYNIAB open day at Morley Farms. Bill Clark, technical director at NIAB. Picture : ANTONY KELLY (Image: archant 2017)

There are five species of brome which occur as weeds in UK arable crops: Sterile or barren, great, soft, meadow, and rye.

But Dr Stephen Moss, a former Rothamsted researcher who is now an independent weed scientist, said it could often be difficult to accurately identify them, and therefore apply the correct treatment.

So he has produced a guide to help farmers distinguish which brome is in their crop, using characteristics including the shape of the spikelets, the length and 'hairiness' of the panicle (the stem carrying the cluster of flowering heads), and the shape of the cross-section of the seeds.

'The identification of these five species of brome is quite difficult, which is why I have produced an identification leaflet to encourage people to identify them more accurately,' he said.

'They tend to be more of a problem in some parts of the country than in others. I think that is partly because where people have got a major problem with black-grass they use herbicides very intensively and control bromes without even thinking about it. In other parts of the country, where black-grass is not so much of a problem, there are more bromes.

'Also, bromes are potentially a bigger risk if you are not ploughing, so the move to minimum-tillage tends to favour bromes – so it is something farmers need to be aware of.'

Dr Moss said great brome, mainly recorded in East Anglia, is one of the species which is not-so-readily controlled with herbicides.

'This is one of the reasons why identification of a brome is important,' he said. 'We have no evidence of herbicide resistance in bromes in the UK, but it has been found in some species in France and Germany. It makes the whole understanding of resistance more complicated, because you have to be sure you are dealing with the right species.'

For more details on brome identification click here.