Management of soilborne Rhizoctonia disease risk in cropping systems

Gupta, V.V.S.R.1, Alan McKay2, Kathy Ophel-Keller2, Nigel Wilhelm2, John Kirkegaard1, Daniel Hüberli3, Bill MacLeod3 and David Roget4
1CSIRO Agriculture Flagship Waite campus and Canberra; 2SARDI Waite campus; 3DAFWA South Perth; 4ex-CSIRO deceased Dec 2013
Research Team: CSIRO – Bill Davoren, Stasia Kroker, Marcus Hicks, Nady Harris, Stephanie Diallo; SARDI – Dan Smith, Amanda Cook and Paul Bogacki; NSW – Peter Hamblin and University of South Australia – Jack Desbiolles
Funding: CSE00048, CSP00150 and CSA00025

Background
Rhizoctonia continues to be an important (average annual cost $59 million with potential costs $165 million, Brennan and Murray, 2009) but complex disease in the southern agricultural region, especially lower rainfall region. The fungus Rhizoctonia solani AG8 is present in Australian soils as part of the microbial community. This pathogenic fungus is a good saprophyte (grows on crop residues and soil organic matter), adapted to dry conditions and lower fertility soils. The aim of this research was to improve our understanding of the interactions between pathogen inoculum levels and natural soil biological activity for long term control of Rhizoctonia and to improve the prediction and management of the disease. A series of multi-year field trials were conducted at sites in SA, Victoria and NSW to determine key soil, environment and management factors influencing the pathogen dynamics and disease impact in cereal crops. These trials were complemented with annual field experiments to investigate the effect of specific management practices including fungicide evaluation.