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Article
Resistance Inducers and Plant Growth Regulators Show only Limited and Transient Effects on Infection Rates, Growth Rates and Symptom Expression of Apple Trees Infected with ‘Candidatus Phytoplasma mali’
Journal of Plant Diseases and Protection
  • Silva Schmidt, Department of Plant Protection, Laimburg Research Centre for Agriculture and Forestry
  • Sanja Baric, Laboratory of Molecular Biology, Laimburg Research Centre for Agriculture and Forestry
  • Maya Massenz, Department of Plant Protection, Laimburg Research Centre for Agriculture and Forestry
  • Thomas Letschka, Laboratory of Molecular Biology, Laimburg Research Centre for Agriculture and Forestry
  • Valerie Vanas, Department of Plant Protection, Laimburg Research Centre for Agriculture and Forestry
  • Manfred Wolf, Department of Plant Protection, Laimburg Research Centre for Agriculture and Forestry
  • Christine Kerschbamer, Laboratory of Molecular Biology, Laimburg Research Centre for Agriculture and Forestry
  • Roland Zelger, Department of Plant Protection, Laimburg Research Centre for Agriculture and Forestry
  • Wolfgang Schweigkofler, Department of Natural Sciences and Mathematics, Dominican University of California
Document Type
Article
Publication Date
1-1-2015
Disciplines
Department
Natural Sciences and Mathematics
Abstract
The effects of four commercially available bio-active compounds on the infection rates, symptom expression and growth rates of apple trees (Malus × domestica Borkh.) cv. Golden Delicious infected with ‘Candidatus Phytoplasma mali’ (the so-called Apple Proliferation phytoplasma or AP) were tested over a three-year period under controlled conditions. Post-infection treatments using Bion® (active ingredient: Acibenzolar-S-Methyl), Messenger® (Harpin protein), Regalis® (Prohexadione-Ca) and Dormex® (Cyanamide) had no significant effect on infection rates. Terminal growth of apple trees (grown as one-shoot pruned trees) was increased significantly by AP infection; Prohexadione-Ca was the only compound which had a significant (inhibiting) effect on the growth of both infected and non-infected apple trees. Acibenzolar-S-Methyl and Harpin had no significant effects on symptom expression. AP symptoms were masked during summer by Prohexadione-Ca, which caused severe growth abnormalities. Cyanamide changed the seasonal appearance of AP symptoms: while symptoms were delayed compared to the untreated control the first two years (2008 and 2009), symptoms appeared earlier the third year (2010). Differences in symptom expression leveled off later in the vegetative season, and no significant difference was found in October.
Publisher Statement
Originally published as Schmidt, S., Baric, S., Massenz, M., Letschka, T., Vanas, V., Wolf, M., Kerschbamer, C., Zelger, R., Schweigkofler, W. (2015). Resistance inducers and plant growth regulators show only limited and transient effects on infection rates, growth rates and symptom expression of apple trees infected with ‘Candidatus Phytoplasma mali’. Journal of Plant Diseases and Protection, 122 (5/6). 207-214.
Citation Information
Silva Schmidt, Sanja Baric, Maya Massenz, Thomas Letschka, et al.. "Resistance Inducers and Plant Growth Regulators Show only Limited and Transient Effects on Infection Rates, Growth Rates and Symptom Expression of Apple Trees Infected with ‘Candidatus Phytoplasma mali’" Journal of Plant Diseases and Protection Vol. 122 Iss. 5 (2015) p. 207 - 214
Available at: http://works.bepress.com/wolfgang_schweigkofler/26/