Comparing spring wheat cultivar mixtures under conventional and organic management in Alberta

A. Kaut1, A. Navabi¹, J. O’Donovan², and D. Spaner¹

Cultivar mixtures may be promising for use in organic or low-input systems by increasing crop heterogeneity and genetic buffering potential. The objective of the present study was to examine the yield response of various two- and three-way spring wheat cultivar (Superb, Intrepid and 5600HR) mixtures under different competition and management regimes. Seed of three elite hard red spring wheat cultivars were mixed in 1:1, 1:2, 2:1, 1:1:1, 1:2:1, 1:1:2, and 2:1:1 ratios and planted, along with pure cultivars, on organic and conventional land, with and without cross-seeded oriental mustard (Brassica juncea), in 2003, 2004, and 2005.

Superb planted as a sole crop tended to yield the greatest under conventional management, while Superb in mixtures with Intrepid performed very well under organic management. Mixtures of Superb and Intrepid maintained yield as weed pressure increased in the 16 environments studied. Many mixtures yielded more grain than Intrepid or 5600HR pure stands.

Our results suggest that wheat cultivar mixtures have potential for stabilizing yield in organic agroecosystems or under conditions of heightened weed pressure or drought stress.

¹Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB.

²Agriculture and Agri-Food Canada, Beaverlodge, AB

Corresponding Author: Amy Kaut makaut@ualberta.ca