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  1. Consider the role that fungicides play in reducing the impact of weather and variety on yields says Dr David Ellerton, Hutchinsons Technical Development Director.

    “One of the key challenges that yields face is the impact of weather - solar radiation, temperature and rainfall - and the effects of disease when weather conditions are conducive to disease development.”

    Whilst there is nothing that can be done about the weather, it is possible to reduce the impact of disease when conditions are challenging by using an appropriate fungicide programme, thereby reducing any further yield losses, he says.

    “We know that wheat yields have plateaued since the late 1990’s – if this had not happened we would be looking at average yields of 9 -10t/ha however in 2011/2012 we saw yields drop down to less than 7t/ha, and this was largely the effect of a dull, wet summer. “

    “The dull wet conditions gave rise to high disease levels, and we saw some of the highest levels of septoria since the mid 1980’s, whilst fusarium hit an all-time high with almost 96% infection of samples. Yellow rust bubbled away in the background affecting more susceptible varieties such as Oakley and Torch, and there was also a massive explosion of brown rust later on in the season.”
     
    However, Dr Ellerton points out that during 2011/2102 across all of the 16 Hutchinsons Regional Technology sites, the average response to fungicides was 2.77t/ha or 44%, despite a low mean treated yield of 9.02 t/ha, so even in a low potential year, the positive effect from fungicides on yield was significant.

    take a protectant approach to keeping diseases such as septoria tritici und

    “Looking more recently at the summer of 2013/2014, conditions could not have been more different to those in 2011/12; sunshine levels were well above the 30 year mean at the important times in the yield forming cycle, April and June/July. It was also wet and mild so crops had good growth but conditions were also ripe for disease. Recorded septoria levels in 2014 were the highest in 15 years according to the Defra winter wheat disease survey,” he adds.

    The mean varietal response to fungicides over all the HLH Regional Technology Centres sites in 2013/14 was 3.28t/ha, a 36.9% benefit, with a mean treated yield of 12.18t/ha, showing that crops made good use of the sunshine. At our Ludlow site, which is on fertile soils but had severe disease challenges, this response was particularly high; the average response to fungicides was 6.77t/ha a 95.2% positive response and an exceptional treated yield of 13.88 t/ha – showing that where there was good control of disease, plants could make yield.

    Dr Ellerton believes the best way to help crops make the most of the available sunshine this coming season is to adopt a protectant approach when planning fungicide programmes. This means that the early sprays are very important.

    “We have seen a drop away in the curativity of the triazoles over the last decade, and although the SDHI fungicides offer some eradication of Septoria they do not have the level of curative action that the triazoles did 15 years ago, so it is important to adopt a protectant approach with the aim of keeping the septoria levels down from the very beginning at T0 and T1 - this means that come the flag leaf spray you are not trying to beat back disease.”
     
    “In fact, the results of some recent trials that we have carried out have shown septoria activity and good yield responses from an autumn/early winter protectant spray, so keeping septoria at bay even this early can have positive effects, and this is something we will be looking closely at again this year.”

    Fungicides not only protect the leaves from disease but also have physiological effects on the plant that also impact on the final yield, even when disease levels are low, he points out.
    “Whilst strobilurin use waned when they lost their efficacy against septoria several years ago, they still do a good job against rust and offer positive physiological effects on rooting and greening - and a combination of SDHI’s and strobilurins have been shown to have a direct impact on size, persistence and levels of chlorophyll in the leaves resulting in greater efficiency of light uptake.”
    Early application is key to maximising these benefits though he adds.

    Choosing the right variety in the first place is also important continues Dr Ellerton. He believes that variety choice needs to be broadened from a tendency to concentrate on the highest yielding varieties on the AHDB Recommended List, to those with better disease resistance.

    “This means that a spread of varieties can be drilled as a risk management strategy; those with lower resistance ratings can be prioritised at spraying leaving some leeway for the varieties with higher disease ratings thereby optimising spray timings to get the most benefit from your fungicides.”

  2. ‘More science more yield’ was the take home message to the 350 farmers in attendance at this year’s Hutchinsons winter technical conference, in Peterborough.

    In recognition of 2015 being the International Year of Soils and also the excellent results achieved in this year’s Yield Enhancement Network (YEN) project, the conference focussed on how soils and yields are intrinsically linked.

    Prof Achim Dobermann, Director of Rothamsted Research, explored the status of yield increases in different crops across the world, and presented his conclusion that climate change is only responsible for 10% of the yield stagnation in wheat in the UK.
    On the contrary, Prof Dobermann highlighted the correlation between yield plateaus and the reductions in the use of nitrogen and phosphorus, noting that the long term work on cereal yields at Rothamsted since 1843 has identified the importance of soil management, and this combined with genetics, are the keys to unlocking the yield barriers.  Prof Dobermann underlined the need to forget the quick fixes and move back to the basics of good agronomy.

    Prof Achim Dobermann of rothamsted speaking at the hutchinsons conference

    Dick Neale, Hutchinsons technical manager, looked at some of the impacts of cultivation techniques on soil health. “Many farmers prepare their seedbeds to accommodate the type of drill that they use, rather than the specific requirements of different crops. It’s key to really look at your soils and understand what issues exist,” he said. Mr Neale raised his concerns that many soil inspections are carried out in the summer when soils are dry and hard, inducing potentially wrong conclusions, in particular regarding soil compaction. He suggested that many of the answers to these problems can be solved by reduced tillage, as a way to increase soil strength, and that the power of plant roots to maintain soil conditions was under-estimated.

    The role of solar energy in the creation of yield
    Farming is about energy conversion and its success depends on capturing and measuring this, was the message from Roger Sylvester Bradley of ADAS. He insisted that with regards to light capture, the choice of varieties plays a major role through the leaf size and leaf angle, and that growers and agronomists must then optimise the development phase of the plant, and secure the protection of the plant through the maturation phase. He identified the key role of the root structure in this process to ensure the maximum capture of water and nutrients in the soil.

    Dr David Ellerton, technical director with Hutchinsons, presented clear evidence of the role in rooting structure of some of the SDHI fungicides, and also of the correlation between a bigger green leaf area with increased photosynthesis.  However, the battle for disease control is being complicated by the development of disease resistance, especially with septoria, yellow rust and fusarium he noted, highlighting that work last year by Hutchinsons and ADAS showed that triazole mixtures gave a better control of disease as different products can have different levels of control of the different strains of septoria.  The work also highlighted the efficacy of SDHIs, and the importance to UK farming of preserving their efficacy through applications in mixtures with other chemical families.

    soil and water were the main themes at this years hutchinsons conference

    Predictable water in unpredictable weather
    Drawing on many years of observations, and using sophisticated weather models, Prof Tim Osborne of the University of East Anglia, led the audience to realise that the future will bring heavy winter rainfall followed by hot and dry summers.  “This will lead to changes in practice for the production of wheat, across the UK and Europe,” he said.  Andy Brown from Anglian Water followed on, explaining the general water requirements in the future caused by the increased population in East Anglia. “Whilst the time deadline looks far away, to get involved in the local consultations over the next 2 years, as these will determine key issues surrounding water storage and availability.”

    Hutchinsons Dr Bob Bulmer closed the presentations by describing some of the growing practices which growers will need to adopt if they want to continue to increase yields. “Essentially farmers and agronomists will need to work together to manage the soil in ways which will permit enhanced water storage and increased root depth for their crops,” he said.