Oat varieties for organic systems

Oats are valuable crop in organic rotations owing to their good nutrient use efficiency and weed competitive ability. Although Leaf Area Index is linked to height, varieties with high LAI but short height would confer good weed suppression with less risk of lodging

Oat variety characteristics for suppressing weeds

Oats are a valuable food source and useful in the crop rotation both in organic and conventional farming systems, partly because of their excellent weed suppression ability. Thomas Döring, Louisa Winkler and Nick Fradgley report new results that show how plant breeding can make oats even better

Cereal Populations - Coping With Unpredictable Weather And Climate

Diverse composite cross populations (CCPs) consisting of thousands of segregating lines are created by crossing a number of parent varietes. Populations demonstrate greater resilience in unfavorable conditions at sowing in Autumn 2012 due to poor weather and high levels of Fusarium infection in seed

Competitive oats for integrated weed management and organic rotations

Using a competitive crop like oats is essential for integrated management of weed problems. Oats can compete well with weeds through efficient nutrient uptake, allelopathy and canopy cover shading. Weeds are suppressed by the crops tillering ability and varieties with good canopy cover. Some varieties can tolerate weeds better by having both good canopy cover and height

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

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

Applications of crop competitive ability in winter oats (Avena sativa L.)

Crop competition is a key component of an integrated approach to weed management. Variation in competitive ability and competitive traits have been identified in many other crop species, however little work has been done on oats. Trials were carried out over four years at one organic site with five husked and three naked oat varieties. Mid-season Leaf Area Index (LAI) and tillering ability were identified as weed suppressive traits using path analysis. Differences in weed tolerance were found among varieties. Trade-offs may exist between competitive traits and yield potential which could be optimised by limiting competitive traits later in the season. Selection of competitive traits with high heritability, whilst minimising yield penalties, could be applied in breeding programmes to develop varieties with greater weed competitive ability

Applications of crop competitive ability in winter oats (Avena sativa L.)

Crop competition is a key component of an integrated approach to weed management. Variation in competitive ability and competitive traits have been identified in many other crop species, however little work has been done on oats. Trials were carried out over four years at one organic site with five husked and three naked oat varieties. Mid-season Leaf Area Index (LAI) and tillering ability were identified as weed suppressive traits using path analysis. Differences in weed tolerance were found among varieties. Trade-offs may exist between competitive traits and yield potential which could be optimised by limiting competitive traits later in the season. Selection of competitive traits with high heritability, whilst minimising yield penalties, could be applied in breeding programmes to develop varieties with greater weed competitive ability

Selecting winter wheat lines from a composite cross population

The extremely diverse genetic variation in wheat Composite Cross Populations (CCP) represents a valuable source of breeding material. Such material could be selected as part of a participatory breeding programme with the potential advantage of selecting adaptation targeted for particular environments. For example, selections could be made aimed at producing lines that would thrive under the wide range of management practices conducted as part of organic and low input farming systems. Ears were selected from a CCP mixed stand under organic field conditions in the UK and Hungary. Selected lines were multiplied as single ear rows and 1m2 plots. The best performing five lines from the two selection sites were trialled in Suffolk, UK, in replicated plots including a commercial control variety (Alchemy) and the original population. Alchemy was chosen due to its good disease resistance and consistent performance at the trial site. Assessments included crop and weed cover, foliar and ear diseases, Leaf Area Index (LAI), crop height, as well as grain and straw yield. The first year of trials has been completed with five of the Hungarian selected lines and trials including locally selected lines are on-going. For the first trial year including only the Hungarian selected lines, there were significant differences among varieties (P<0.001) and Alchemy had the highest average yield. Across all trial entries grain yield was correlated negatively with yellow rust infection on the flag leaf at heading (P<0.001) and with reduced green leaf area during grain ripening (P<0.001). In current trials including locally selected lines, some of the selected lines had significantly lower yellow rust infection than the average of the original CCP and of the control variety Alchemy (P<0.001). There was also greater early ground cover (P<0.005) and (LAI) at tillering (P<0.05) in some lines compared to Alchemy and the original population. Crop cover was also correlated negatively with early weed cover (P<0.05). These observations suggest that it is possible to select lines with enhanced resistance to local disease and the ability to compete with weeds at an early stage. However, because average grain yields and percentage protein content are negatively correlated in this study (P<0.01), this trade-off should not be ignored when selecting lines for specific end uses. This can be avoided by developing mixtures of high performing lines with potentially greater stability than pure-line monocultures. Such mixtures may perform better than the original CCP but with the risk of reduced stability over multiple seasons because of their reduced diversity. Acknowledgements: The work reported here is supported by the EU Core Organic II project COBRA

μCT trait analysis reveals morphometric differences between domesticated temperate small grain cereals and their wild relatives

Wheat and barley are two of the founder crops domesticated in the Fertile Crescent, and currently represent crops of major economic importance in temperate regions. Due to impacts on yield, quality and end-use, grain morphometric traits remain an important goal for modern breeding programmes and are believed to have been selected for by human populations. To directly and accurately assess the three-dimensional (3D) characteristics of grains, we combine X-ray microcomputed tomography (μCT) imaging techniques with bespoke image analysis tools and mathematical modelling to investigate how grain size and shape vary across wild and domesticated wheat and barley. We find that grain depth and, to a lesser extent, width are major drivers of shape change and that these traits are still relatively plastic in modern bread wheat varieties. Significant changes in grain depth are also observed to be associated with differences in ploidy. Finally, we present a model that can accurately predict the wild or domesticated status of a grain from a given taxa based on the relationship between three morphometric parameters (length, width and depth) and suggest its general applicability to both archaeological identification studies and breeding programmes.Agências financiadoras: Biotechnology and Biological Sciences Research Council (BBSRC) grant, 'National Capability in Crop Phenotyping' (BB/J004464/1); (BB/CAP1730/1) BBSRC grant, 'MAGIC CARPET' (BB/M011666/1) NERC (NE/M010805/1) ERC (339941)info:eu-repo/semantics/publishedVersio