Severity of root rot in mature subterranean clover and associated fungal pathogens in the wheatbelt of Western Australia

Authors

Tim Scanlon, DPIRDFollow
Tiernan A. O’Rourke, University of Western AustraliaFollow
Martin J. Barbetti, DPIRDFollow
Megan H. Ryan, University of Western Australia
Len J. Wade, University of Western Australia
Alan C. McKay, South Australian Research Development Institute
Ian T. Riley, South Australian Research Development Institute
Hua Li, University of Western Australia
Krishnapillai Sivasithamparam, University of Western Australia

Document Type

Article

Publication Date

1-5-2009

Journal Title

Crop and Pasture Science

Keywords

Root disease, Subterranean clover, Subclover, Phytophthora clandestina, Rhizoctonia solani, Pythium

Disciplines

Agricultural Science | Agriculture | Agronomy and Crop Sciences | Environmental Microbiology and Microbial Ecology | Plant Pathology

Abstract

Pasture decline is considered to be a serious challenge to agricultural productivity of subterranean clover across southern Australia. Root disease is a significant contributing factor to pasture decline. However, root disease assessments are generally carried out in the early part of the growing season and in areas predominantly sown to permanent pastures. For this reason, in spring 2004, a survey was undertaken to determine the severity of root disease in mature subterranean clover plants in pastures located in the wheatbelt of Western Australia. DNA-based soil assays were used to estimate population density in the soil of a variety of soil-borne pathogens known to commonly occur in the Mediterranean-type environments of southern Australia. The relationships between severity of disease on tap and lateral roots and root diameter, root length, nodulation, and total rainfall were determined. The survey showed, for the first time, that severe root disease is widespread in spring across the wheatbelt of Western Australia. There was a positive correlation between rainfall and tap root disease, and between tap root disease and average root diameter of the entire root system. Despite the high levels of root disease present across the sites, the DNAof most root disease pathogens assayed was detected in trace concentrations. Only Pythium Clade F showed highDNA concentrations in the soil.DNA concentrations in the soil, in particular for Phytophthora clandestina and Rhizoctonia solani AG 2.1 and AG 2.2, were higher in the smaller autumn sampling in 2006. This study suggests that the productivity of subterranean clover-based pastures is severely compromised by root rot diseases throughout the growing season in the wheatbelt of Western Australia.

Comments

https://www.publish.csiro.au/cp/CP08187

https://doi.org/10.1071/CP08187

Recommended Citation

O’Rourke Tiernan A., Scanlon Tim T., Ryan Megan H., Wade Len J., McKay Alan C., Riley Ian T., Li Hua, Sivasithamparam Krishnapillai, Barbetti Martin J. (2009) Severity of root rot in mature subterranean clover and associated fungal pathogens in the wheatbelt of Western Australia. Crop and Pasture Science 60, 43-50. https://doi.org/10.1071/CP08187