Organic Winter Wheat Variety Trial Results

Whenever I read about variety trials in organic systems the sage words of Prof. Martin Woolfe come to mind.  His view is “The most important aspect of yield organically is the fertility of the soil the crop is grown in, the second most important thing is the growing season and a long way third is the variety”.  That said prior to planting there is little that can be done to significantly improve soil fertility and there is nothing that can be done about the growing season and so varietal choice becomes important as it is a factor of the production cycle that is within the producer’s control which is possibly why farmers place a lot of importance on varietal choice.

A further comment is that it is worth looking at the statistics behind the trial results.  Seed merchants always focus on top yield.  However, the trials are designed and analysed to provide robust information to support decision making.  It is worth noting that the results will show whether the yield figures provided for a variety are significantly different from other varieties in the trial.  If the yields of two varieties are not significantly different from each other then you can conclude that were the trial to be repeated the same ranking would not be expected.  Just because one variety has a higher yield DOES NOT mean it will have a higher yield if the trial were repeated unless the yield is shown to be significantly different from the second variety.  Make use of all the information supplied to make management decisions not just some of it.

With these provisos ringing in your ears below are the results from the trials run by Organic Seed Producers at both Shimpling Park Farm,  Suffolk and Rectory Farm, Buckinghamshire (where the National Organic Cereals 2014 was held).  The results seem to largely confirm Martyn Woolfe’s hypothesis that variety makes little difference whilst the system does.

The vast majority of the variety’s do not show any statistically significant difference in yield at either site.  How can this be when the yield for Revelation at Shimpling Park is 1 t /ha greater than Croft?  Indeed it does but the results also show this is not significant.  This means that were the trial repeated the same results would not be predicted and so Croft could just as easily outyield Revelation.

 

OSP Winter Wheat Variety Trials at Rectory Farm and Shimpling Park

OSP Winter Wheat Variety Trials at Rectory Farm and Shimpling Park

 

On another note.  I have a  soft spot for Claire.  In  ORC trials in the early Noughties it was a reliable performer and looking up the data in ORC Bulletin 64 Dec 2002. A yield of 4.35 t /ha was achieved with Claire topping the yield chart.  The trials then were held at Chadacre Farms a neighbour of Shimpling Park and so a reasonable comparison.  So 12 years later on the same variety yielded 4.2 t /ha.  -quite consistent performance.