Apple rubbery wood

Apple rubbery wood is a persistent and damaging disease caused by a phytoplasma known as the Apple rubbery wood phytoplasma. This pathogen interferes with the natural lignification process of the xylem, causing the branches of affected apple trees to lose their rigidity and become flexible like rubber.

The disease primarily affects apple trees, with various cultivars showing different levels of susceptibility. Because the pathogen is systemic, it spreads horizontally primarily through grafting and budding. Using infected rootstocks or scion wood is the most common way for the disease to enter an orchard and become established over many years.

The primary symptom is the distinctive "rubbery" texture of current-season and older branches. Under the weight of fruit or even just gravity, branches will bend significantly without snapping back to their original position. Over time, this structural instability compromises the tree's ability to support fruit loads and alters the overall architecture of the canopy.

Beyond structural changes, the disease has a significant impact on overall tree health. Infected trees often exhibit stunted growth, reduced vigor, and a decline in fruit quality and yield. In many cases, the disease remains latent for long periods, making it difficult to detect until the structural symptoms become clearly visible as the tree ages.

Management of apple rubbery wood relies strictly on sanitary practices. There are no curative treatments, so the most effective strategy is to avoid infection by using certified virus-free planting material. Growers should regularly monitor their orchards and remove infected trees immediately to prevent the spread of the pathogen, especially in areas where grafting is performed frequently.