Damage to roots of Trifolium subterraneum L. (subterranean clover), failure of seedlings to establish and the presence of root pathogens during autumn-winter
Date
2011
Authors
Simpson, Richard J.
Richardson, Alan E.
Riley, Ian Timothy
McKay, Alan C.
McKay, Suzanne Faye
Ballard, Ross A.
Ophel-Keller, Kathy
Hartley, D.
O'Rourke, Tiernan A.
Li, Hua
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Journal article
Citation
Grass and Forage Science, 2011; 66(4):585-605
Statement of Responsibility
R. J. Simpson, A. E. Richardson, I. T. Riley, A. C. McKay, S. F. McKay, R. A. Ballard, K. Ophel-Keller, D. Hartley, T. A. O’Rourke, H. Li, K. Sivasithamparam, M. H. Ryan and M. J. Barbetti
Conference Name
Abstract
Field-based plant bioassays were employed to assess the potential for pre- and post-emergence loss of seedlings and for root damage affecting Trifolium subterraneum L. (subterranean clover) during autumn–winter at 17 pasture sites across a broad agricultural area of temperate southern Australia. Between 9 and 93% (median 21%) of T. subterranean seedlings failed to emerge at the 14 locations where soil moisture was considered adequate for germination. Post-emergence losses were lower (range 0–32%; median 7%). Moderate damage (lateral roots) to severe damage (taproots) was recorded on surviving test plants at all of the sites. Sublethal damage to pasture roots constitutes a potentially large, but underestimated cost to production because it was so widespread and because the damage occurs during autumn–winter when pasture yield limits stocking rate. Potential for the loss of Lolium rigidum × multiflorum (annual ryegrass) seedlings was also demonstrated at some of the sites. DNA assays for common root rot disease pathogens (Pythium irregulare, Phytopthora clandestina and Rhizoctonia) were used for the first time to construct cost-effective profiles of fungal and oomycete pathogens at each site. These assays may be useful for indicating disease risks and guiding plant cultivar selection and appropriate use of pesticides. DNA assays for arbuscular mycorrhizal fungi were also used and have the potential to provide novel insights into the soil biology of farming systems.
School/Discipline
School of Agriculture, Food and Wine
Dissertation Note
Provenance
Description
Access Status
Rights
© 2011 Blackwell Publishing Ltd