Biodiversity as a creator of productivity and interspecific competitiveness of winter cereal species in mixed cropping

- Productivity of rye and triticale depends on the share of the species in the mixture.
- Wheat was always dominated by other species in a two- or three-species canopy.
- The high competitiveness of rye translates to increased grain yield per spike.
- Strong competitiveness of triticale towards wheat does not increase grain yield per spike.
- Wheat can be recommended for cultivation in a mixture with triticale.

The study evaluated the productivity of three species of winter cereals - wheat, rye, and triticale - in sole cropping and in mixtures of two and three species. Asymmetrical interspecific competition was noted during generative growth stages. The greatest competitive strength was observed for triticale in the mixture with wheat during the heading stage. In the two-species mixtures with equal proportions (50:50), triticale produced greater biomass. In the three-species mixture, the productivity of rye and triticale depended mainly on their initial high share in the crop (50%). Wheat, despite having a high share in the mixture, did not display high productivity, because the yield per spike and harvest index decreased. Rye in the mixed cropping with wheat produced significantly higher spike weight and culm weight in comparison with sole cropping. Triticale, despite being strongly competitive in the canopy during the generative growth phase, attained high grain yield per spike. The low competition coefficients for triticale relative to rye suggest that these two species have a similar competitive pressure during the period of harvests.