Fungicides that are effective against canker, particularly for use in the growing season, are currently limited. AHDB funded Project TF 216 'Evaluation of products for control of Nectria galligena on apples' to assess fungicides and biological control agents for their efficacy in controlling Nectria fruit rot and canker.
In a two-year trial to control Neonectria fruit rot, Syllit 400 SC, Delan Pro and an experimental product all significantly reduced Neonectria fruit rot by up to 50 per cent in the first year.
In follow-up trials in year two, the incidence of fruit rot was low due to weather conditions, so results were not statistically significant. However, the lowest incidence was recorded in programmes based on Syllit 400 SC, Delan Pro and two experimental products.
In the first year of the canker trial on cv. Gala, similar products were evaluated, with Folicur (tebuconazole) included as the standard. Despite favourable wet weather during leaf fall in 2014, the incidence of new cankers on extension shoots was low with no significant effects of the treatments on canker incidence.
The trial was repeated with Braeburn in the second year. No significant effects were seen in the different treatments, although the lowest numbers of cankers were recorded on plots treated with Folicur, Bellis, Syllit 400SC, Captan, Serenade + wetter and an experimental product.
The full Grower Summary for Project TF 216 is available on the AHDB Horticulture website at horticulture.ahdb.org.uk.
For details on all AHDB Horticulture activity, see horticulture.ahdb.org.uk