A thorough attention to agronomic detail and a solid grasp of integrated pest management (IPM) should be at the heart of a thriving arable business, delegates learned at the 2014 HGCA Agronomists’ Conference.

Over 350 agronomists, growers and other members of the arable industry attended the conference on 9 December 2014 in Peterborough.

A series of thought-provoking presentations saw leading experts discuss three IPM areas: performance of plant protection products, rethinking rotations and using monitoring techniques to best effect.

The key point cutting through the diverse topics was that a delicate balance needs to be struck if the short- and long-term requirements of the cereals and oilseeds sector are to be met. This balance requires a firm understanding of agronomic information so the range of resources at farmers’ fingertips can be deployed to best effect and protected for the longer term.

The conference was opened by Jonathan Tipples, arable farmer and Chairman of the HGCA Board, who said that the answer to crop protection challenges “is less likely to come out of a can”, with the solutions now coming from using “all the tools in the toolbox”.

Conference chair, Clare Bend, HGCA Research and Knowledge Transfer Committee member and Head of Technology and Services, Agrii, echoed these thoughts, adding that the agricultural advisory network in the UK is populated with thousands of people translating agronomic information. She said what unites this diverse group is the commitment to do the best for their customers and to give advice based on robust science, such as that provided by HGCA.

Strengths and weaknesses of fungicides

The conference kicked off with an in-depth analysis of the strengths and weaknesses of a range of cereal fungicides, with a presentation delivered by Stuart Knight, Director of Crops & Agronomy, NIAB.

The relatively high disease pressures in 2014 had tested the mettle of the products trialled, leading to good protectant and eradicant data. However, delegates were reminded of the importance of looking at several years’ data to iron out the influence of seasonal variation.

For septoria tritici control in wheat, the continued decline in azole activity meant straight azoles remained somewhat off the pace set by the other products/active ingredients tested.

The SDHI/azole mixtures trialled were closely matched and largely superior to solo SDHIs – showing azoles can still play a useful role.

The multi-site products tested also remained valuable as protectants, with an important role in resistance management.

Solo SDHIs tested in trials were also highly active but delegates were reminded that SDHIs should always be mixed with at least one fungicide with an alternative mode of action that has efficacy against the target pathogen.

For brown rust control in wheat, the strobilurin fungicide Comet was considered to be the star of 2014. For yellow rust control in wheat, SDHI/azoles mixtures, Comet and straight azoles gave good control, while the straight SDHIs were weaker.

For barley, the trials in 2014 saw greater differentiation between the solo SDHIs tested, with Imtrex performing relatively well, especially on rhynchosporium and net blotch. The SDHI/azole mixtures trialled also performed relatively well against the target diseases, Siltra Xpro and Adexar were consistent, whereas Vertisan plus Proline was slightly weaker on rhynchosporium protection in 2014.

Mr Knight concluded with a statement on the importance on not relying on straight actives. Where trials were challenged by more than one disease, there was a yield benefit from the SHDH/azole mixtures compared to straights in addition to the important role of mixtures in resistance management.

Sustaining fungicide performance

Neil Paveley, Crop Protection Lead, ADAS, looked at the evolution of cereal spray timings. Using the example of septoria control, he said that there has been a trend towards more fungicide applications. He considered this a very risky strategy due to the propensity of cereal pathogens to develop resistance to agrochemicals.

Delegates were urged not to focus on growing pristine crops, as this tactic only tends to wipe out the susceptible individuals in any particular pathogen population adding to the resistance pressure, “a crop should be as clean as it needs to be and no cleaner,” he added.

A lack of control was felt unlikely to be at the heart of the decision to add sprays beyond T1 and T2, indeed, evidence was presented suggesting there is better control now for septoria than in the early 90s. The reason was felt to be more likely due to other drivers, such as increases in crop value making the decision to spray easier, the quicker sporulation of yellow rust and the increased value placed on using a T3 ear wash spray.

Delegates were warned that the increase in the number of sprays is putting pressure on the system and more needed to be done to protect precious chemistry. Based on a global review of all crop pathogens, the overwhelming conclusion was that adding a mixture partner with a different mode of action can significantly slow down the development of resistance.

The important role of varietal disease resistance genes was also highlighted. The incentive for growers to select Recommended List varieties with good disease resistance was considered low as these varieties tend to be from the lower end of the yield spectrum. However, early trials results are showing that combining resistant varieties with a low/moderate fungicide input programme could be economically more worthwhile than many people currently think.

The power shift in rotations

Jack Watts, Lead Analyst, AHDB Market Intelligence, described the current “power shift” in rotations. In particular, the big shift in the production of winter oilseed rape was cited – in 2012 the crop was a strong performer but lower prices and other agronomic pressures were now forcing growers to look at other break crop options.

Estimates show beans have taken some of the land but the decision to try something new must make business sense. Mr Watts said that growers must consider the premium associated with any crop before planting and then grow it well to meet the quality specifications to secure that premium.

Mr Watts also said the UK is becoming a “world producer of barley” as, unlike wheat and maize, global production is not on an upward trend, providing a great opportunity for the UK to compete on the global stage.

Handle on costs

Mr Watts concluded with a warning that the industry is going to have to get a better handle on production costs, including more tricky ones – such as organic matter values – if it is to fully capitalise on rotational opportunities.

Pulses were the subject of discussion by Stephen Belcher, Principal Technical Officer, PGRO. He outlined the numerous benefits to the arable rotation from incorporating pulses, including not only the agronomic benefits associated with nitrogen residues and weed control but also the ability to satisfy the requirements of the Basic Payment Scheme. Economic benefits were also covered. Pulses have a strong global market demand, with beans trading at a premium of at least £30 over wheat, with a further £15-30 premium for beans destined for human consumption.

Attention to detail

Echoing Mr Watts’ statement, Mr Belcher reemphasised that quality is critical for reaching the top premiums and growers should not be tempted to skimp on inputs where they are required. If attention is paid to the agronomic detail, then gross margins associated with peas and beans are good compared to other crops in the arable rotation, he concluded.

Rethinking inputs in winter barley

With the current winter barley area estimated to be significantly higher this year compared to last, Pete Berry, Head of Crop Physiology at ADAS, discussed how average yields are well below varietal yield potential – even after accounting for lower nitrogen (N) specifications associated with some markets.

As there is a strong relationship in barley between grain number and final yield, delegates heard how the key to yield is to maximise crucial early light interception between emergence and grain set.

Optimising N

New HGCA project results, based on a review of 25 N timing experiments to optimise N timings/rate in winter barley, were presented. The results showed a 0.5t/ha yield increase from applying more than 50% N before early stem extension, compared with less than 30% N as recommended in RB209.

Delegates were also informed that winter barley with yield potential of more than 8t/ha is hungry and benefited from an additional 27kg N/ha for each tonne above 8t/ha.

On average, the earlier N strategy was found to reduce grain N by 0.1%, which needs to be considered for a variety of market specifications. Due to increases in lodging risk, the importance of selecting appropriate plant growth regulators was deemed important – in particular, growers were reminded not to rely on chlormequat, where strong lodging was sought.

Learning from IPM pioneers

Denmark has had a long history of pressure from government and authorities to reduce the use of pesticides over the last 30 years – including the highest pesticide taxes in the world. As a consequence, Danish growers have fewer chemical tools in the toolbox than UK growers.

Jens Erik Jensen, Senior Adviser, Knowledge Centre for Agriculture, Denmark, explained how this pressure has led to the motto in the country being, ‘as little as possible, but as much as necessary’ and has driven a whole raft of innovations in IPM.

Millions of pounds are being invested in IPM demonstration farms, advisory packages and pest and disease monitoring services, to make IPM realistic and beneficial to Danish growers. Emphasis is also being placed on benchmarking current IPM practices so improvement can be measured.

Giant vacuum cleaners

The conference concluded with a celebration of a long-serving example of IPM. Richard Harrington, Head of Rothamsted Insect Survey, Rothamsted Research, discussed the data collected from the ‘giant upside down vacuum cleaners’ in the insect suction trap network.

The network celebrated its 50th birthday on 29 April this year and has played a key part in understanding the behaviour of aphid populations in the UK, including the resistance mechanisms and crop viruses they carry.

Delegates were told that the high level of resistance to pirimicarb and pyrethroids in peach-potato aphids is still a worrying feature in aphid samples trapped in 2014, with the stark warning that it is only a matter of time before neonicotinoid (nAChR) resistance, already present in France, hits the UK population. Resistance in grain aphid also appears to have levelled off and it looks like the resistance arose from a single individual aphid that now dominates the UK arable area.

Information from the conference, including conference papers with results from a voting session on neonicotinoids, is available from www.hgca.com/agconf

Save the date

The HGCA Agronomists Conference 2015 takes place on Tuesday 8 December 2015