Sub-Clover Project Update

Sub-clover is a vital component of Barossa pasture systems and in 2014 Barossa Improved Grazing Group (BIGG) received a three-year Producer Research Sites grant ($70,000) from Meat & Livestock Australia (MLA) to investigate the effect of soil borne root diseases on local sub-clover productivity.

As part of the project, in 2014 BIGG conducted various small plot trials, the results of which were presented at a project meeting held in Adelaide in January 2015. The meeting included participants from BIGG, Rural Directions (MLA’s SA project coordinators), The University of WA (the project’s research partner) and the Mackillop Farm Management Group which, like BIGG, received an MLA grant and are investigating soil borne root diseases on sub-clover in their region (south-east SA).

BIGG’s 2014 trials were conducted at Moculta (Murray and Ben Klemm’s property) and Eden Valley (David Woodard’s property) and evaluated the productivity of three different sub-clover cultivars (Clare, Trikkala and Woogenenellup) with and without the fungicide seed treatment metalaxyl. Metalaxyl is registered for the control of seedling diseases caused by pythium and phytophthora in sub-clover but has not been trialled locally.

Treatments in the trials were sown in one metre row plotand assessed for seedling emergence (2-5 weeks after sowing), plant nodulation and dry matter production throughout the growing season. Although soil borne root diseases were known to be present at both trial sites, the results indicated that no clear conclusions could be drawn on metalaxyl’s effectiveness to reduce the impact of root diseases. This was also complicated by the short growing season, with well below average rainfall occurring in late winter/spring at both sites.

The meeting also reviewed BIGG’s field trials plans for 2015, which include further investigations with metalaxyl. They complement a range of similar field research that the University of WA is planning to conduct at a trial site in the Barossa this year. These trials will include chemical seed and spray treatments, cultivation and livestock grazing as potential root disease management strategies in sub-clover.