Wheat Variety Trials

Jerry Alford reports on the 2018 wheat variety trials organised by the Organic Research Centre

What wheat variety to grow? That’s the question asked by arable farmers, and a question that leads to more questions about end users, drilling dates, weed profiles, weather and disease risks.

For an organic farmer many of the answers come from conventional sources. In fact, all new varieties are grown for high-input systems and a one-size-fits all attitude means there are not really any regional varieties, despite disease pressures in the West being different from those in the East. Additionally, untreated yields in the recommended list have all inputs except fungicide, so plots are more likely to be compromised by the lushness of a heavily fertilised crop. Only seven of the 27 trial plots record untreated yields, which reduces the value of the list for an organic farmer.

  

Innovative Farmers variety trial

For these reasons, and to give farmers operating low-input systems some assistance with variety choice, Innovative Farmers set up an organic wheat trial at Bradwell Grove near Burford. With research input from the Organic Research Centre, it was aimed at finding varieties suited to organic farming systems.

With initial advice from Bill Angus from Angus Wheat Consultants and David Neale from Agrii, a list of varieties was chosen, including some experimental varieties, European and heritage varieties, plus commercial varieties thought suitable for organic.

On the ground

Drilled in replicated plots on 28 October 2017, the trial was harvested in August 2018. During the season growth, disease levels and plant heights were assessed, plus yield and protein analysis at harvest. Weather at drilling meant that the seed bed wasn’t rolled, while drought on the Cotswold brash meant that the trial was testing for all varieties. Less than ideal germination meant that weed competitiveness was not assessed, although the drought resulted in low weed levels.

Ear density was well below the ideal of 400, due to poor germination and drought, so yield will have been compromised; however, it was consistent. Maris Widgeon, a thatching straw wheat, was expected to be taller. Yellow rust was as expected, with no evidence except in Skyfall, which is known to be high risk. With brown rust, the weather was kind and only Crusoe showed any evidence, again in keeping with its known risk. Septoria infection was present but only at low levels as expected. Yield and protein results were lower than expected due to the germination and weather issues and were lower than the rest of the field of Revelation, which yielded 3.7t/ha.

Frustratingly, Mortimer, the highest yielding variety in the trial, will not be available commercially this year because the breeder has been unable to find a seed company willing to sell it, as it is too similar to all the other varieties. It is interesting that a graph of protein percentage against yield (see below) shows the expected trendline of high yield, low protein, but three varieties do stand out above the line and these may be better suited to organic where it is not easy to manipulate nitrogen and protein levels.

What next?

The trial is being repeated for 2019 harvest with some new varieties, including a Swedish variety and three more experimental varieties. We are growing varieties across a group of farms, run as a balanced incomplete block design, where farmers grow an area of three different varieties, with each variety being grown on one other farm. This trial structure allows comparisons to be made between varieties and regions and is an easy way to assess a variety’s potential without the need for trials to be set up in every region.

As a form of farmer science, everyone can be part of the variety trial.

To find out more about the trials contact Jerry Alford at the Soil Association or visit the Organic Wheat Variety trials field lab page. 

Jerry Alford is Arable and Soils Advisor at the Soil Association.

This article was first published in the Soil Association Organic Farming magazine Winter 2019 Issue 129.

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