Mechanical failure, known as lodging, negatively impacts yield and grain quality in crops. Limiting crop loss from lodging requires an understanding of the plant traits that contribute to lodging-resistance. In maize, specialized aerial brace roots are reported to reduce root lodging. However, their direct contribution to plant biomechanics has not been measured. In this manuscript, we find that brace roots establish a rigid base (i.e. stalk anchorage) to limit plant deflection in maize. The more brace root whorls that contact the soil, the greater the contribution of brace roots to anchorage. Previous studies have linked the number of brace root whorls to flowering time in maize. To determine if flowering time selection alters the brace root contribution to anchorage, a subset of the Hallauer’s Tusón tropical population was analyzed. Despite a significant change in flowering time, selection neither altered the number of brace root whorls in the soil nor the overall contribution of brace roots to anchorage. These results demonstrate that brace roots provide a rigid base in maize, but the contribution to anchorage is not linearly related to flowering time.

The failure of crop plants to maintain a vertical position is referred to as lodging and can affect both crop yield and grain quality (Berry

Plant mechanical failure (lodging) causes global yield losses of 7%−66% in cereal crops. We have previously shown that the above-ground nodal roots (brace roots) in maize are critical for anchorage. However, it is unknown how brace root phenotypes vary across genotypes and the functional consequence of this variation. This study quantifies the contribution of brace roots to anchorage, brace root traits, plant height, and root lodging susceptibility in 52 maize inbred lines. We show that the contribution of brace roots to anchorage and root lodging susceptibility varies among genotypes and this contribution can be explained by plant architectural variation. Additionally, supervised machine learning models were developed and show that multiple plant architectural phenotypes can predict the contribution of brace roots to anchorage and root lodging susceptibility. Together these data define the plant architectures that are important in lodging resistance and show that the contribution of brace roots to anchorage is a good proxy for root lodging susceptibility.