Dead spur

Dead spur is a serious condition affecting apple trees, characterized by the progressive necrosis of short fruiting spurs. It is often caused by fungal pathogens, most notably Phomopsis mali or Cytospora species, which invade the plant tissue through small wounds or cracks in the bark of the spurs.

The disease is classified as a necrotic infection that attacks the cambium and xylem, preventing the flow of nutrients to the fruiting buds. Because the spurs are the primary sites of fruit production, the death of these structures directly results in significant yield loss for the orchardist.

Symptoms appear as the wilting and browning of the spurs during the growing season. The bark becomes shriveled, and the buds fail to develop into flowers or leaves. In later stages, the infection can spread from the spurs into the larger branches, causing sunken cankers and eventually leading to the death of major limbs.

Development is favored by environmental stress, particularly cold injury, sunscald, or improper pruning cuts that leave the wood vulnerable. Warm, wet weather facilitates the production and spread of fungal spores, which are then disseminated by wind, splashing rain, or pruning tools throughout the canopy.

The economic impact of Dead spur can be devastating if left unmanaged, as it reduces the reproductive capacity of the tree. Chronic infestation leads to sparse foliage, reduced fruit quality, and increased susceptibility to other secondary pests and pathogens, eventually shortening the tree's productive lifespan.

• Sanitary pruning of dead or infected spurs, ensuring cuts are made into healthy tissue.
• Sterilization of pruning tools with appropriate disinfectants after every tree.
• Painting pruning wounds with protective fungicides or wound sealants.
• Maintaining tree vigor through proper fertilization and irrigation management.
• Regular application of protective copper-based sprays during dormant and budding stages.