Research matters ... control of raspberry flowering

Dr Ken Cockshull, Emeritus Fellow at Warwick HRI, highlights the latest findings from horticultural research.

Raspberries can be produced out-of-season today mainly because past research established the environmental factors that controlled growth and flowering.

Most of that research was done almost 50 years ago and so it was necessary to ensure that the cultivars grown today responded similarly. In the research described here, 'Glen Ample', a modern cultivar widely used for out-of-season production, was raised in pots of compost in naturally lit controlled-environment chambers.

When grown at different temperatures in the natural day-lengths of autumn, growth stopped soon after the plants were transferred to temperatures of 12 degsC or less and flower formation began at the same time. Flowers were formed later at 15 degsC, but none were found at 18 degsC. When grown at 15 degsC but in different day-lengths, flower-bud initiation occurred in day-lengths of 15 hours or less. Thus flower initiation and the cessation of growth require low temperatures together with relatively short days. The plants then require to be exposed to cold for many more weeks before their dormancy is broken.

Finally, canes failed to form flowers if they had 10 or fewer leaves at the start of treatment. This research should allow better out-of-season fruiting schedules to be produced.

Environmental Control of Growth and Flowering of Rubus Idaeus L. Glen Ample by Sonsteby and Heide (2008). Scientia Horticulturae 117: 240-256. The contents of issues of Scientia Horticulturae and abstracts of papers are provided at www.elsevier.com/locate/scihorti.


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