Research Matters - Chlorophyll and nitrogen status

As nitrogen is essential for plant growth and can also determine plant quality, it is important that it is supplied in adequate quantity to meet the needs of crops. The best approach is to monitor the nitrogen content of plant tissues and then adjust the nitrogen supply accordingly. Plant tissues can be analysed chemically to determine their nitrogen content, but it is a time-consuming procedure.

An alternative, indirect but quicker approach might be to measure leaf greenness because chlorophyll content is usually related to nitrogen content. The Soil-Plant Analyses Development (SPAD) chlorophyll meter estimates chlorophyll content, as does the Normalised Difference Vegetation Index (NDVI).

In the present experiments, seeds of two geranium cultivars ('Horizon Deep Red' and 'Horizon Tangerine') were grown in pots and watered with solutions containing 0mg, 50mg, 100mg and 200mg per litre of nitrogen. The SPAD meter was used to scan four mature leaves per plant and an NDVI pocket sensor was used to scan whole plants. Leaves were then removed from each plant and analysed chemically for nitrogen content.

Although SPAD values for the two cultivars differed, NDVI and SPAD values were related to leaf nitrogen content. The SPAD meter would evidently have to be calibrated for each cultivar but then either sensor could be used to monitor the nitrogen content of geranium leaves.

Dr Ken Cockshull, Associate Fellow, Warwick Crop Centre, University of Warwick

Use of An Active Canopy Sensor & SPAD Chlorophyll Meter to Quantify Geranium Nitrogen Status by Wang, Dunn, Arnall and Mao (2012). HortScience 47 (1): 45-50. The author's abstract can now be seen in full at http://hortsci.ashspublications.org but ISHS members can view HortScience online at www.ishs.org.


Have you registered with us yet?

Register now to enjoy more articles and free email bulletins

Sign up now
Already registered?
Sign in

Before commenting please read our rules for commenting on articles.

If you see a comment you find offensive, you can flag it as inappropriate. In the top right-hand corner of an individual comment, you will see 'flag as inappropriate'. Clicking this prompts us to review the comment. For further information see our rules for commenting on articles.

comments powered by Disqus

Read These Next

What is being done to develop biocontrols against orchard pests?

What is being done to develop biocontrols against orchard pests?

The SIVAL horticultural trade show in Angers, France, this week (16-18 January) heard about several initiatives to promote more environmentally sustainable orchard growing.

What does the 25-year plan mean for growers?

What does the 25-year plan mean for growers?

Published on 11 January, the Government's long-awaited 'A Green Future: Our 25 Year Plan to Improve the Environment' brings together a number of policy strands into a single framework that will impact many sectors, not least fresh produce, over the coming decades.

What will 'embracing change' mean for horticulture?

What will 'embracing change' mean for horticulture?

At the Oxford Farming Conference, whose theme was "embracing change", Defra secretary Michael Gove expanded on what a post-Brexit UK agriculture and land-use policy will look like and how it will impact farmers and growers.


Follow us on:
  • Facebook
  • LinkedIn
  • Twitter
  • Google +
Horticulture Jobs
More Horticulture Jobs

Pest & Disease Tracker bulletin 

The latest pest and disease alerts, how to treat them, plus EAMU updates, sent direct to your inbox.

Sign up here

Professor Geoffrey Dixon

GreenGene International chair Geoff Dixon on the business of fresh produce production
 

Read Professor Geoffrey Dixon