Root-to-shoot ratio
nounPronunciation: /ˈruːt tə ʃuːt ˈreɪʃəʊ/
The biomass proportion of a plant's root system relative to its above-ground shoot tissue, used as an indicator of resource allocation patterns under stress. Plants typically increase this ratio under drought or nutrient-limited conditions to enhance water and nutrient acquisition.
Plain English
A measure comparing the amount of plant biomass below ground to above ground, reflecting stress adaptation strategies.
Etymology & History
Usage
"The root-to-shoot ratio increased significantly in drought-treated maize compared to well-watered controls."
Style guide notes: Write as 'root-to-shoot ratio' with hyphens; abbreviate as R:S or R/S only in figures and tables.
Also known as
Contrasted with
Related Terms
Frequently Asked Questions
Why do plants increase root-to-shoot ratio under drought?
Greater root biomass enhances water absorption capacity from progressively deeper, drier soil layers.
How is root-to-shoot ratio calculated?
Divide total root dry biomass by total shoot dry biomass; expressed as a decimal or percentage.
Why Test Candidates on This?
Commonly assessed in field trials and greenhouse studies evaluating stress tolerance and growth allocation strategies.
Required skill level: Junior