Science Into Practice - Understanding downy mildew on impatiens

Seed and cutting-raised impatiens are important crops for the bedding plant industry, with an estimated retail value of £40m. Impatiens downy mildew has been an intermittent problem since 2003, with severe outbreaks recorded in 2008 and 2011. Research was urgently required to understand the pathogen, where it originated from, how it spread and how to control it.

Seed transmission has not been proven, so the most likely route of any outbreak is infected cutting material. Spore production in infected crops is sometimes noted on nurseries but the work also identified resting spores that permit the disease to overwinter in UK conditions on plant debris. Such spores can pose a threat to impatiens planted out in infected soil the following year.

A range of fungicide spray programmes were examined in HDC project PC 230a/b and protectant programmes were generally identified as the most effective for control. In terms of curative activity, drenches were more effective than foliar sprays. Cultural control recommendations were also provided as part of the project.

Although several effective and crop-safe products were identified, the introduction of metalaxyl-M-resistant isolates in 2011 highlighted the need to review and target fungicide programmes according to current infections.

Further HDC-funded work is due to start later this year to monitor the development of the metalaxyl-M-resistant isolate and to develop effective fungicide programmes based on a number of other active ingredients.

Dates for your diary

17 April HDC/Cut Flower Centre Conference, Springfields, Spalding.

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

Papaver

Papaver

These compact, brightly coloured flowers can be very attractive for impulse sales, notes Miranda Kimberley.

Fertilisers Special Report - invaluable nutrition

Fertilisers Special Report - invaluable nutrition

Using the right fertilisers on your crops can make all the difference when it comes to securing repeat customers, Sally Drury advises.

IPM Essen Show Preview - New look for top trade fair

IPM Essen Show Preview - New look for top trade fair

Venue modernisation will mean better display space for exhibitors at Europe's largest trade fair for the horticulture industry, says Gavin McEwan.


Opinion... Gardening needs better promotion

Opinion... Gardening needs better promotion

British horticultural firms and organisations have not been the best at working together to promote our industry.

Opinion... A wish list for unblinkered thinking

Opinion... A wish list for unblinkered thinking

Opinion... A wish list for unblinkered thinking

Opinion... A wish list for unblinkered thinking

Generations of ordinary British people have been let down by weak, visionless leaders -- politicians more engaged by the next election than our national best interest.


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

Tim Edwards

Boningales Nursery chairman Tim Edwards on the business of ornamentals production
 

Read Tim Edwards

Ornamentals ranking

Top 30 Ornamentals Nurseries by Turnover 2017

Top 30 Ornamentals Nurseries by Turnover 2017

Tough retail pricing policies and Brexit opportunities drive the top 30 growth strategies.

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

Are you a landscape supplier?

Horticulture Week Landscape Project Leads

If so, you should be receiving our new service for Horticulture Week subscribers delivering landscape project leads from live, approved, planning applications across the UK.

Peter Seabrook

Inspiration and insight from travels around the horticultural world
 

Read more Peter Seabrook articles