Abstract
Sugarcane root systems are poorly studied and understood due to the perennial nature, tall stature, and the long cropping cycle. Whilst some field studies gave insights into sugarcane root traits, there is no detailed description of root and root system traits available. The objectives of our work were to establish a baseline of sugarcane root trait values that will serve for future studies, and to characterize the degree of root system resilience when restricting tiller number. We first conducted an initial screening for root trait diversity on a collection of twenty cultivars representative of sugarcane breeding from 1930 to now. Then we investigated the effect of reduced tillering, via manual de-tillering, on the plant root and root system traits of five varieties grown under optimal conditions in a glasshouse for 1700°Cd. In addition to establishing baseline means and variation for sugarcane root trait values that could serve as a reference for crop models, we demonstrated that the sugarcane root mass fraction was extremely resilient to drastic reduction in tiller number. Restricted plants were effectively maintaining their root system configuration (opening angle) by dramatically increasing the number of nodal roots produced per tiller as well as maximizing total root length by increasing the specific root length. Using this knowledge of sugarcane root traits in combination with the specific agronomic constraints for sugarcane will now underpin the development of a root system ideotype for sugarcane to enable targeted root trait selection for improving crop productivity.
Highlights
Sugarcane is a tall perennial crop planted vegetatively from setts and allowed to regrow over multiple years after harvest (Bonnett, 2013)
In the experiment on the effect of tillering restriction on sugarcane root systems, we demonstrated that root mass fraction (RMF) in each genotype remained unchanged even when tiller number was drastically reduced
The results suggest that it may be difficult overcome the resilience of this trait to increase the allocation of resources and create a larger root system
Summary
Sugarcane is a tall perennial crop planted vegetatively from setts and allowed to regrow over multiple years after harvest (ratoon crop) (Bonnett, 2013). Of the analyses of sugarcane root systems have used a limited number of varieties and samples, relying on small soil samples from the field to determine root length density and root biomass and derive information on sugarcane root distribution over time in the soil From these multiple studies, it has been shown that the maximum rooting depth appears to be between 4.25 m and 4.7 m (Laclau and Laclau, 2009) or even up to 6 m (Evans, 1935) and is little influenced by rainfed or irrigated conditions, which suggests that this trait is under genetic control (Laclau and Laclau, 2009). Given the variability among these observations, it has been noted that bigger scale experiments with larger numbers of varieties and pedoclimatic conditions would be needed to determine a general pattern for sugarcane root biomass distribution
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call