Performance of three endophytic actinomycetes in relation to plant growth promotion and biological control of Pythium aphanidermatum, a pathogen of cucumber under commercial field production conditions in the United Arab Emirates

Khaled A. El-Tarabily, Giles E.St J. Hardy, Krishnapillai Sivasithamparam

Research output: Contribution to journalArticlepeer-review

39 Citations (Scopus)

Abstract

In the current study, the performance of three endophytic actinomycetes identified as Actinoplanes campanulatus, Micromonospora chalcea and Streptomyces spiralis previously shown to reduce seedling damping-off, and root and crown rots of mature cucumber (Cucumis sativus) caused by Pythium aphanidermatum in pots under greenhouse conditions were further evaluated to determine their potential as biological control agents and as plant growth promoters in the field under the conditions of commercial production of cucumbers in the United Arab Emirates (UAE). When applied individually or in combination to cucumber seedlings, the three isolates significantly promoted plant growth and yield and reduced seedling damping-off and root and crown rots of mature cucumber plants. Individually the performance level of S. spiralis was relatively the best followed by A. campanulatus and then by M. chalcea. The three isolates (which were not inhibitory to each other) performed better, both as biological control agents as well as plant growth promoters, when applied together than when they were inoculated individually. The ability of these three isolates to colonize the internal tissues of roots, stems and leaves under field conditions, and to persist up to 8 weeks after seedling inoculation, showed that they can easily adapt to an endophytic habit systemically within healthy cucumber plants. As the three endophytic actinomycete isolates also colonized the rhizosphere and showed outstanding rhizosphere competency it is clear that they are facultative and not obligate endophytes. The success with the three inoculants indicated that they could well be used in place of the fungicide metalaxyl which is currently recommended for the management of Pythium diseases in the UAE. This is the first successful field use of endophytic actinomycetes as promising plant growth promoters and biological control agents against Pythium diseases of cucumber.

Original languageEnglish
Pages (from-to)527-539
Number of pages13
JournalEuropean Journal of Plant Pathology
Volume128
Issue number4
DOIs
Publication statusPublished - Dec 1 2010

Keywords

  • Biological inoculants
  • Disease control
  • Microbial interaction
  • Soil-borne plant pathogens

ASJC Scopus subject areas

  • Agronomy and Crop Science
  • Plant Science
  • Horticulture

Fingerprint

Dive into the research topics of 'Performance of three endophytic actinomycetes in relation to plant growth promotion and biological control of Pythium aphanidermatum, a pathogen of cucumber under commercial field production conditions in the United Arab Emirates'. Together they form a unique fingerprint.

Cite this