Impacts of vegetative and reproductive plasticity associated with tillering in maize crops in low-yielding environments: A physiological framework

•Modern maize hybrids sown at low densities tiller in non-restrictive environments.•Light quality and plant growth rate at early stages govern tiller emission.•Tiller fertility would be determined by shoot growth rate around flowering.•Reproductive plasticity is needed to stabilize yields in ultra-low density settings.•The impact of tillering on crop water and nitrogen economies is hypothesized.