Root interactions and biomass allocation

Evolution in nature is driven by individual fitness, but the goal in agriculture is to optimize population performance. There is evidence that higher yields achieved by the breeding of new crop cultivars over recent decades have been due in part to reductions in “selfish” traits and behaviours, which increase fitness but reduce population performance. To test this hypothesis, we conducted a greenhouse experiment with a traditional landrace and a modern cultivar of spring wheat (Triticum aestivum), gown (1) in mixture and monoculture, (2) at four densities, (3) two watering levels, and (4) with permeable vs. non-permeable soil dividers. We supplemented the greenhouse experiment with a field competition experiment within and between the two cultivars.