The efficiency with which crops use captured resources to produce biomass and yield is an important adaptive trait for grain yield improvement. It is underpinned by one of the main plant processes – photosynthesis – drawing significant attention to research photosynthetic improvement. However, leaf photosynthesis is only a subcomponent of the whole-crop growth, development, and yield system. The relationship between leaf photosynthesis and grain yield is non-linear and can be confounded by the interactions between the biology of the plants with their environment. Recent cross-scale crop growth modelling advances have helped formalised the intricate physiological network that connects leaf and canopy photosynthesis[1] with crop growth and yield[2,3]. Here I will describe the cross-scale modelling and showcase findings from our modelling studies:
- In variable water conditions, which encompass most dryland cropping situations globally, yield outcome in crop plants with increased leaf photosynthetic rates is more complex than previously thought, highlighting the importance of photosynthesis-stomatal conductance link[2,4].
- Leaves in crop canopies are mostly exposed to low light levels over the diurnal cycle, revealing that leaf-scale photosynthetic low-light response and its temperature dependency are important targets for improving the potential efficiency with which crop stands use intercepted solar energy to produce biomass[5].
By understanding complex physiological network linking leaf and canopy photosynthesis, crop-scale performance, and environmental interactions via mechanistic crop modelling, this has unlocked the ability for predicting likely crop yield outcomes and is a research avenue for generating testable hypotheses, helping to inform bioengineering strategies for crop yield improvement.