Within-crop genetic diversity increases temporal yield stability in organic winter wheat

Summary

Organic farming aims at developing farming systems that do not need unsustainable inputs such as mineral fertilisers and pesticides to regulate the cropping environment. Such systems need crop varieties that are resilient against multiple and variable biotic and abiotic stresses and that make efficient use of the nutrients and resources that are available. Highly genetically diverse cereal Composite Cross Populations (CCPs) have been proposed as an approach to dealing with these stresses (Döring et al., 2011).
Field trials investigated the yield stability of two winter wheat CCPs compared to two respective mixtures of their parental varieties as well as high yielding (c.v. Alchemy) and high quality (c.v. Solstice) elite pure-line control varieties at an organic and a non-organic site in the east of England over four trial seasons.
The more diverse CCPs demonstrated more favourable static and dynamic yield stability (Annicchiarico, 2002) over the four trial seasons than the respective variety mixtures and the two pure-line varieties at both the organic and non-organic sites. However, an advantage of this stability was found only at the organic site where both the CCPs were higher yielding than the mixtures in the year with the lowest average yields.
These results indicate that although the yield potential of CCPs is limited in optimal environments, they are more advantageous at maintaining yield in more adverse environments, such as on organic farms. This supports evidence that diverse crops are able to make efficient use of resources through mechanisms of resilience including compensation, complementation and facilitation (Creissen et al., 2013). These approaches will become increasingly important with increasing challenges from climate change and reduced fossil fuel availability.
We acknowledge funding from the European Community’s 7th Framework Programme (FP7/ 2007-2013) under grant agreement no. 245058 SOLIBAM.