Farm Table says:
What is the problem?
Organic farming aims at developing farming systems that do not need unsustainable inputs such as mineral fertilizers 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. This is created by inter-crossing selected parent varieties in all combinations.
What did the research involve?
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.
The research took place in the east of England over four trial seasons.
What were the key findings?
- Diverse CCPs are able to maintain yield in the most adverse (low yielding) environments but their yield potential is limited in high-input (higher yielding) environments.
- CCPs are a useful tool for organic farming or low input farming systems, where biotic and abiotic stresses, such as limited nutrients, weed competition, and crop diseases, are expected.
- Yield stability is a more useful measure of variety performance in organic systems than average yield per se.
- As such, yield stability will be increasingly important in dealing with unpredictable stresses over time, including those caused by global climate change and increasingly limited resources.
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.