Refining breeding methods for organic and low-input agriculture: analysis of an international winter wheat ring test

Abstract

International audienceAn increasing interest in sustainable forms of agriculture exists worldwide and the demand for varieties specifically adapted to organic and low-input agriculture is rising. As a consequence, breeding methods need to be refined accordingly. In order to get better insight into needs and possibilities with this regard, a comprehensive ring test was performed from 2006 to 2008 with 14 winter wheat varieties in 36 environments in major cropping regions of Austria, France, Romania and Switzerland. Environments were grouped into 9 different subsets according to input systems, years, and countries. Input system N0 consisted of 13 organic and 6 no-input trials; 17 trials in input system N received various levels of synthetic nitrogen. For grain yield (YLD) and protein yield (PYLD), significant G x E was detected. Countries had a stronger effect on both traits than systems. Overall, it was more efficient to select YLD and PYLD in N, for targeting both systems N and N0. For PYLD, direct testing within a given country was always more efficient than indirect selection. Many traits could be scored equally well in both systems, N and N0, but for some traits particularly important for organic agriculture, such as soil coverage, better differentiation was observed under organic conditions. Therefore, we agree with other authors that a commercially sustainable breeding program for organic and low-input agriculture should combine information from high and low-input levels and from diverse regions. Local testing of varieties, however, remains indispensabl

Plant breeding for organic agriculture: something new?

“…This can be seen as one of the elements under which the Green Revolution took place [59]: shuttle breeding, which consists in exchanging segregating generations between different environments to achieve wide adaptation or broad disease resistance. Alternation of germplasm between CF and OF at later segregating generations is considered an important component of commercially sustainable OPB programs by some authors [60][61][62]. A modality of this shuttle breeding scheme, is to only carry out selections of advanced generation progenies, developed by conventional breeding procedures, under optimum organic environments to determine their value for cultivation and use in further testing; this is advantageous, particularly when there is limitation of financial, human, and institutional resources in OPB.…”

Conventional versus organic farming systems: dissecting comparisons to improve cereal organic breeding strategies

“…Such strong environmental pressure under organic conditions is highlighted in breeding programs by yield heritability estimates in organic multi-environment trials. Indeed, the mean yield heritability estimated under organic conditions is generally reduced compared to that estimated under high-and low-input conditions (Ceccarelli 1994;Kokare et al 2014;Le Campion et al 2014;Messmer et al 2012;Muellner et al 2014;Reid et al 2009). However, it is difficult to precisely characterize the components involved in such heterogeneity due to multiple limiting factors.…”

Wheat cultivar yield response to some organic and conventional farming conditions and the yield potential of mixtures

“…High N trial conditions alone gave poor prediction of yield performance under organic conditions, whilst low N trials were better (Le Campion et al 2014). However, a combination of low input, organic and conventional conditions, and multiple environments was identified as desirable to enable robust selection (Muellner et al 2014). Different traits show different responses to selection environment so, in practice, a combination of environments is needed for selection of balanced new cultivars (Mikó et al 2014).…”