Apple shoot addiction

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Witch's broom at the top of a tree infested with apple shoots

Apple shoot addiction is one of the most important apple diseases. It is triggered by phytoplasms .

Symptoms and harm

Symptoms include a witch's broom and enlarged stipules .

The economic damage is:

  • Small fruit (about 80% of the infected tree are affected)
  • Poor yield and growth
  • poor ripeness of the fruit

As a countermeasure, it is recommended that the affected trees be cleared immediately. The affected plants can live on for a long time with the disease, but the further development of yield is very poor and can only be improved by replacing the trees. In addition, the infected plants form a source of infection for all other apple trees.

Less severely infested trees can recover after two years of good care; this requires the consistent removal of all infested areas and all root shoots.

Spread and spread

The apple shoot addiction was first described in 1950 in Veneto (Italy). Currently, apple shoot addiction has only been proven in Europe.

The pathogen is mostly transmitted by the summer apple leaf sucker Cacopsylla picta (synonym: Cacopsylla costalis ) in Central Europe. In addition, the hawthorn leaf sucker Cacopsylla melanoneura also plays a certain role in the spread of the disease, at least in north-western Italy.

Neighboring trees can transmit the pathogens through the roots growing together. In the case of direct replanting, the old parts of the roots should therefore also be removed carefully. The phytoplasm is also often transmitted through grafting work .

literature

  • Kunze, L. (1988): "Apple proliferation." In: Ian M. Smith (Ed.): European Handbook of Plant Diseases. Wiley-Blackwell, London, pp. 118-120.
  • Klaehre, D. (2008): "Apple instinct - state of knowledge from theory and practice." In: Commercial fruit growing 50 (1), 13–17. ( doi : 10.1007 / s10341-007-0051-y )

Web links

Individual evidence

  1. ↑ Preventive measures
  2. ↑ Daniel Pascal Klaehre: Apple instinct - state of knowledge from theory and practice. In: Commercial fruit growing . Springer-Verlag, Berlin Heidelberg March 2008, Volume 50 (1), pp. 13-17, ISSN 0014-0309, doi : 10.1007 / s10341-007-0051-y .