Skip to main content Accessibility help
×
Home

What are the effects of nitrogen deficiency on growth components of lettuce?

  • M. R. BROADLEY (a1), A. J. ESCOBAR-GUTIÉRREZ (a1), A. BURNS (a1) and I. G. BURNS (a1)

Abstract

Relationships between nitrogen (N) content and growth are routinely measured in plants. This study determined the effects of N on the separate morphological and physiological components of plant growth, to assess how N-limited growth is effected through these components. Lettuce (Lactuca sativa) plants were grown hydroponically under contrasting N-supply regimes, with the external N supply either maintained continuously throughout the period of study, or withdrawn for up to 14 d. Richards' growth functions, selected using an objective curve-fitting technique, accounted for 99.0 and 99.1% of the variation in plant dry weight for control and N-limited plants respectively. Sublinear relationships occurred between N and relative growth rates under restricted N-supply conditions, consistent with previous observations. There were effects of treatment on morphological and physiological components of growth. Leaf weight ratio increased over time in control plants and decreased in N- limited plants. Shoot:root ratio followed a similar pattern. On a whole-plant basis, assimilation of carbon decreased in N-limited plants, a response paralleled by differences in stomatal conductance between treatments. Changes in C assimilation, expressed as a function of stomatal conductance to water vapour, suggest that the effects of N limitation on growth did not result directly from a lack of photosynthetic enzymes. Relationships between plant N content and components of growth will depend on the availability of different N pools for remobilization and use within the plant.

Copyright

Corresponding author

Author for correspondence (fax +44 1789 470 552; e-mail martin.broadley@hri.ac.uk).

Keywords

What are the effects of nitrogen deficiency on growth components of lettuce?

  • M. R. BROADLEY (a1), A. J. ESCOBAR-GUTIÉRREZ (a1), A. BURNS (a1) and I. G. BURNS (a1)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed