Science Into Practice - Crop lighting for ornamentals

The phasing-out of tungsten bulbs led HDC to investigate alternatives (PC 296).

Compact fluorescent bulbs are cheap but their spectrum lacks far red light, which impacts flowering and plant growth. LEDs can supply light at specific wavelengths.

Compact fluorescent bulbs were studied for night break and day-extension treatments for long-day and short-day ornamentals. Then two off-the-shelf LED systems were tested with modules to deliver red, far-red or blue light, or mixtures of red and far-red, and Philips' Green Power lamp in far red only, red and white and a mix of red, far red and white.

The fluorescent bulbs controlled flowering in chrysanthemum, poinsettia and fuchsia as effectively as tungsten but did not control flowering for half of the plants tested, probably because of the lack of far red, important for day-extension lighting. The Green Power lamps emitting red, far red and white elicited an equivalent response to tungsten in all plants bar Christmas cactus.

The far red lamps gave good flowering control for half the species but increased stretching. The red and white lamps were not useful except for chrysanthemum but proved better than tungsten with this species.

With the LED modules, red and far red combinations got a better plant response than red or far red alone. Effective flowering control of most species could be controlled by a mixed module of 25 per cent red and 75 per cent far red. But the high far red increased stretching in many species and using a 75:25 mix would be an improvement in most cases.

Horticultural Development Company

For details on all HDC activity, visit www.hdc.org.uk.


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

How should fruit growers prepare for water abstraction reform?

How should fruit growers prepare for water abstraction reform?

Upcoming reforms to water abstraction licensing will for the first time cap the amount of water that fruit growers can take for trickle irrigation.

Getting a measure of the production labour crisis

Getting a measure of the production labour crisis

At a debate during last week's Fruit Focus trade show in Kent, senior industry figures painted a bleak picture of an increasingly difficult seasonal labour market that is already impacting on investment.

What will post-Brexit pesticides authorisation and capital support for fresh produce look like?

What will post-Brexit pesticides authorisation and capital support for fresh produce look like?

The likely impact on seasonal labour has dominated discussions of the consequences of withdrawal from the EU for UK production horticulture.


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