Realized gains from selection for spring wheat grain yield are different in conventional and organically managed systems

Abstract

Breeding spring wheat (Triticum aestivum L.) specifically for organic production has been suggested by producers and researchers alike. To investigate the effects of management systems on selected spring wheat breeding line performance in multi-location tests in the northern Great Plains, we used a randomly derived population of 79 F6-derived recombinant inbred lines (RILs) from a cross between the Canadian hard red spring wheat cultivar AC Barrie and the CIMMYT derived cultivar Attila. The population, including the parents, was grown on conventionally and organically managed land in 12 environments over 3 years. Direct selection in each management system (10% selection intensity based on grain yield) resulted in three lines being retained in each management system, over the multi-location testing. Gains from 10% selection for grain yield in a 'selection' year were 3.4 times greater in conventional multi-site yield trials than in organically managed trials. Two lines (BA 05 and BA 36) ranked in the top 10% of both the conventional and organic selection trial of 2005, remained ranked 2nd and 1st, respectively, under conventional management in multi-site yield trials. However, these lines ranked 53rd and 21st, respectively, for grain yield in the multi-site organic yield trials. Selected lines were each yield stable within the management system in which they were selected. Following replicated multilocation yield trials, three lines from the population (BA 02, 29 and 58) ranked within the highest 10% yielding lines in both conventional and organic systems. The results of this study suggest that selection differences occur across multi-location tests, and that selection for grain yield in organic systems should be conducted within organic systems. It is evident, however, that data obtained from conventional yield trials also has some relevance towards breeding for organic environments.

Structuring an Efficient Organic Wheat Breeding Program

“…Organic production systems are typically, though not always, different from conventional systems in soil nutrient status (E and M), fertility inputs (M), resilience to drought conditions (E and M), nitrogen mineralization rate (E and M), and timing of key operations such as planting date (M) [4,5]. Hence it is expected that the same genotypes in an organic and conventional cropping system will have different phenotypes even when grown under identical climatic or weather conditions, which has been confirmed by previous research [4,6,7].…”

Genetic Variation and Phenotypic Response of 15 Sweet Corn (Zea mays L.) Hybrids to Population Density

“…This experiment was conducted under conventional agronomic practices, and the results are applicable to both farming systems. However, as has been shown in previous studies, genotype by environment interactions can cause rank changes to occur in the performance of cultivars between conventional and organic systems [28,29]. While this study suggests inbred parents that have the potential to adapt to higher planting densities, lines identified for organic farming systems should be tested under organic conditions to evaluate their performance in the environment of intended use.…”

Review: Redesigning Canadian prairie cropping systems for profitability, sustainability, and resilience

“…Breeders in both Manitoba and Alberta have found that spring wheat (Triticum aestivum L.) lines selected under organic management outyielded conventionally selected lines when all were grown under organic management, and concluded that targeted crop breeding programmes for organic varieties would be beneficial (Reid et al 2011;Kirk et al 2012). Similar effects have been observed in other crops such as lentil (Lens culinaris Medik.…”