Cultural control (Apple canker)

• Remove Neonectria cankers from orchards during winter pruning. Smaller cankers can be pruned out completely. Larger cankers on the trunk or scaffold branches can be pared back to healthy tissue and treated with a suitable wound protectant paint immediately after.
• Cut out shoot dieback due to canker in the spring.
• Avoid pruning in wet conditions.
• Un-macerated (un-pulverised) cankered prunings left in the tree row can continue to produce spores (ascospores) for at least 1-2 years and therefore are a canker risk.
• In areas where conditions favour canker, remove prunings from the orchard and burn.
• If this is considered too costly, alternatively dump all prunings, including young shoots, in the grass alleyway and pulverise to ensure rapid decay.
• Repeated mowing of grass and prunings will increase the speed of breakdown.
• Avoid dumping young cankered shoots in the tree row as these can generate more inoculum.
• Remove mummified fruit from trees and from under trees and either remove from orchard or throw into alleyway to be macerated.
• Prune trees to open and encourage air circulation to improve tree drying out and reduce surface moisture and conditions favourable for canker.
• Avoid use of high nitrogen, especially farmyard manure as that will encourage canker.

BBSRC, The East Malling Trust and British Apples and Pears Ltd funded a research project between 2023 and 2025 to investigate if there is any correlation between canker incidence and soil properties both between and within orchard sites. Orchard data including physical and chemical soil properties were collected from 72 orchards of a similar age and using the varieties Gala, Braeburn and Jazz. Niab scientists tried to correlate the average number of cankers recorded across all assessed trees with the average soil parameters recorded in the orchard.

• Orchard soils with high levels of organic matter, total carbon, total nitrogen, calcium, soil cation exchange capacity (CEC) and a high percentage of clay content, had on average higher levels of canker.
• Those orchards with soils recording high levels of iron, molybdenum and silt had on average lower levels of canker.
• At present, it is not known if levels of these parameters have a major influence on canker development and more work is needed to validate these results.
• The link between increased iron and molybdenum and lower canker will be further investigated in a British Apples and Pears Ltd funded project called PROSPER where different fertigation regimes will be applied to trees and canker response measured.