Seasonal susceptibility of apple trees to <i>Neonectria ditissima</i> wound infections

  • S.A.M. Alves Embrapa Grape and Wine, BR 285, km 115, Vacaria, RS, Brazil
  • C.C. Nunes Embrapa Grape and Wine, BR 285, km 115, Vacaria, RS, Brazil
Keywords: European canker, Malus domestica, Nectria galligena, Neonectria ditissima, apple, wound

Abstract

European canker, caused by Neonectria ditissima, is an important disease of apple in the temperate climate of southern Brazil. Monthly inoculations of this fungus were carried out on various wound types on cvs ‘Gala’ and ‘Fuji’ over two productive cycles to better understand the seasonal susceptibility of apple trees. Wound types were: bud scars (September), petal scars (October), fruit-thinning scars (November), leaf scars (from November to May), fruit-picking wound scars for ‘Gala’ (February) and ‘Fuji’ (March), and pruning wounds (June to August). One hundred plants of each cultivar were used and inoculation sites were monitored periodically for symptom expression. At each assessment, visible lesions were counted and pruned, and wounds were painted. Differences in wound susceptibility occurred throughout the year. Most lesions resulted from inoculations of pruning wounds. Inoculations performed in spring on bud and petal scars resulted in lower disease expression than inoculations later in the season.

Published
2017-08-08
How to Cite
Alves, S., & Nunes, C. (2017). Seasonal susceptibility of apple trees to <i>Neonectria ditissima</i&gt; wound infections. New Zealand Plant Protection, 70, 73-77. Retrieved from http://journal.nzpps.org/index.php/nzpp/article/view/30
Section
Vol 70 Apple Pathology 2017