Identification of sugarcane stages prone to root and stem lodging and the role of nitrogen management in enhancing resilience

Abstract

Contexts or problem

Sugarcane is by far the most extensively grown sugar-producing crop worldwide. Unfortunately, its lengthy life cycle and erect stature have rendered it notoriously vulnerable to lodging. Whilst some studies have provided insights into the overall lodging of sugarcane, there is a lack of a detailed description that simultaneously considers both stem and root lodgings throughout the entire growth period of sugarcane and under different N rates.

Objective or research question

The aim of this study was to identify the most sensitive stage of sugarcane towards lodging and determine traits that can confer tolerance, particularly under higher levels of nitrogen (N) application.

Methods

Here, we explored the stem and root lodging resistance of field-grown susceptible (Zhongtang 1) and resistant (Zhongtang 3) sugarcane varieties using “safety factor” technique under different levels of N for three consecutive years.

Results

The most sensitive stages for stem lodging and root lodgings were identified as 180 and 210 days after planting, respectively. An N rate of 300 kg ha^–1 was found to be appropriate, balancing the trade-off between sugar yield and crop lodging resistance while ensuring the maximum achievable yield under current condition. Key traits that contributed towards lodging tolerance such as enhanced stem bending strength and root anchorage strength, flexural rigidity, and diameter and mass density of the lower stem, were also identified.

Conclusions and implications

Root lodging was relatively more prevalent than stem lodging throughout the entire growth period. Future breeding programs should prioritize sugarcane varieties with rigid root systems by increasing biomass allocation to the roots, which can strengthen their mechanical properties and ultimately enhance lodging resistance.