Science Into Practice - Bacterial canker on plum trees

Bacterial canker is a destructive disease of plums and cherries that has been causing ongoing problems for growers for many years.

It can be caused by two distinct pathovars of Pseudomonas syringae - pv. morsprunorum (Psm) and pv. syringae (Pss). Psm is host-specific to Prunus spp., whereas Pss has a much wider host range.

Products containing copper have traditionally been relied on for control. AHDB Horticulture-funded Project TF 217 set out to identify whether there is any evidence of copper resistance in UK populations of the above two pathovars and to develop new control guidelines.

No evidence of resistance appeared in the Psm isolates tested, but some was apparent in those of Pss. However, these were not completely resistant to copper and growth was still inhibited at higher copper concentrations, but it does highlight the need to understand which pathogen is responsible for causing disease in any particular orchard.

Spray trials to identify the most effective control products showed that the copper product Cuprokylt + wetter (Activator 90) is still the most effective chemical control option available for bacterial canker caused by Psm. Copper sprays may be less effective against Pss due to the presence of resistance strains, so growers should seek accurate diagnosis of their orchard strain.

In another AHDB-funded project on ornamental cherries, the highest levels of Psm were seen in the spring and summer, so the current label recommendations for three sprays in late summer may be starting too late to have a significant impact and growers may wish to consider earlier spray applications.

The full grower summary for Project TF 217 is available on the AHDB Horticulture website - horticulture.ahdb.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

Read These Next

What should growers make of the Government's migration report?

What should growers make of the Government's migration report?

By holding out the "possibility" of a seasonal agricultural workers scheme (SAWS), the Migration Advisory Committee's (MAC) long-awaited final report, published this week, makes an exception for fresh produce amid its wider call for a shift away from low-skill immigration.

Tractors: market roundup

Tractors: market roundup

Manufacturers are working to provide solutions to many challenges. Sally Drury looks at their newest models.

What does the Agriculture Bill mean for growers?

What does the Agriculture Bill mean for growers?

The publication of the Agriculture Bill this week formally kick-starts the Government's plans to implement a "green Brexit" for farming, the area of the economy most impacted by the UK's withdrawal from the EU from next March.


Follow us on:
  • Facebook
  • LinkedIn
  • Twitter
  • Google +

Horticulture Week Top UK FRUIT PRODUCERS

See our exclusive RANKING of UK Fruit Producers by annual turnover plus the FULL REPORT AND ANALYSIS.

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