What was it all about?

With an increasing number of foliar and flower diseases placing constraints on pyrethrum production – reducing yields and the lifespan of crops – and fungicide resistance a rising cost and risk, this three-year investment worked  to aid pyrethrum growers in minimising these issues.

The work drew to a close in late 2020, and involved research into the key pathogens that can affect pyrethrum production, the timing of their influence, and their susceptibility to fungicides.

The project team found that tan spot is now the dominant pathogen pyrethrum growers contend with during the spring period, while ray blight has displaced sclerotinia and botrytis flower blights as the main disease affecting flowering heads in summer. 

These findings, coupled with the results of fungicide efficacy trials, have resulted in changes to the industry’s recommended spray programs, with the removal of a previously recommended product. At the time of writing, the industry was seeking registration of an alternative product based on this work.

In addition, the industry is now considering the project’s recommendation to reduce the number of sprays used during the summer period, due to an apparent lack of yield benefit identified by the research team, and the potential to reduce the economic and environmental costs of production.

Overall, the project highlighted the potential to tailor disease management recommendations to local and/or seasonal conditions. To that end, further knowledge of the environmental influence on fungal disease, especially on tan spot, is required.