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Basic Technical IVT Commonly tested

stomatal conductance threshold

noun

Pronunciation: /ˈstɒmətəl kənˈdʌktəns ˈθreʃoʊld/

The critical value of stomatal aperture opening at which stomatal closure is triggered in response to water deficit or other environmental stressors. Below this threshold, stomata close to prevent excessive water loss through transpiration.

Plain English

The minimum level of stomatal opening that plants allow before closing their pores to save water during stress.

Etymology & History

Origin languageGreek, Latin
Rootstoma (mouth) + conducere (to lead) + threshold (doorway)
First recorded use1980s
Usage frequencyCommon

Usage

"The stomatal conductance threshold of drought-resistant cultivars is lower than susceptible varieties, enabling earlier stress avoidance."

Style guide notes: Specify measurement units (mol m⁻² s⁻¹) when citing numerical thresholds for consistency across publications.

Also known as

stomatal closure point critical stomatal conductance

Contrasted with

maximum stomatal aperture

Related Terms

Frequently Asked Questions

Why is stomatal conductance threshold important in crop breeding?

Lower thresholds indicate earlier stress avoidance, improving water-use efficiency and yield stability under water scarcity.

How is stomatal conductance threshold measured in research?

Measured using porometers or gas exchange systems that track stomatal opening as soil water stress increases.

Why Test Candidates on This?

Critical in crop physiology and plant breeding assessments for evaluating drought tolerance and stress adaptation strategies.

Required skill level: Mid

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