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Potassium phosphate induces systemic protection in barley to powdery mildew infection
Author(s) -
Mitchell Anne F,
Walters Dale R
Publication year - 2004
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.795
Subject(s) - powdery mildew , blumeria graminis , mildew , biology , hordeum vulgare , inoculation , phosphate , potassium , agronomy , horticulture , potassium phosphate , peroxidase , phenylalanine ammonia lyase , poaceae , chemistry , plant disease resistance , enzyme , biochemistry , organic chemistry , chromatography , gene
Abstract In laboratory tests, treatment of the first leaves of barley ( Hordeum vulgare L cv Golden Promise) with potassium phosphate led to significant reduction in infection of the second leaves with the powdery mildew fungus Blumeria graminis f sp hordei Marchal, with a 25 m M treatment giving 89% reduction in infection. Although the optimal interval between phosphate treatment of the first leaves and mildew inoculation of the second leaves was 2 days, significant protection was still obtained if the interval was increased to 12 days. Protection against powdery mildew infection was not as effective when the potassium phosphate was applied as a seed treatment or root drench. Phosphate treatment of the first leaves led to significant increases in activities of phenylalanine ammonia lyase (PAL), peroxidase and lipoxygenase in second leaves. Enzyme activities, especially PAL and peroxidase, were increased further when second leaves of phosphate‐treated plants were inoculated with powdery mildew. Phosphate treatment of the first leaves did not adversely affect plant growth and, in a field trial, 25 m M potassium phosphate provided 70% control of mildew and gave a small increase in grain yield. Copyright © 2004 Society of Chemical Industry