Appropriate fungicide doses on winter barley: Producing dose-response data for a decision guide

Abstract

The aim of the research was to provide an independent source of information about the activity of current and newly introduced fungicides. The diseases investigated were rhynchosporium, brown rust, powdery mildew, net blotch and ramularia. Protectant and eradicant properties were measured in field trials carried out throughout the UK and Eire under high disease pressure conditions. The efficacy of fungicides does not remain static, and the results on disease control from this research can be used alongside other evidence to highlight situations where the efficacy of disease control may be changing in the field. It was important to ensure growers received the most up to date information about the activity of fungicides, so the research aimed to deliver the results to growers annually at HGCA Disease Roadshows.

The project has shown that the fungicides Proline, Fandango and Tracker provide the core components to manage barley diseases and achieve optimum. Two new experimental fungicides are potentially a major step forward in the control of net blotch and brown rust and also provide an alternative option to control ramularia leaf spot. Yield responses are similar to the most effective fungicides currently available. For powdery mildew control, Flexity, Torch extra and Cyflamid continue to show effective control, but Talius has not performed as well.

Getting the results out to the HGCA members quickly meant the procedures in assessing trials, collecting data, analysis and dissemination were all focussed on achieving this aim. This research collected four years' data. A previous project collected three years' data. Together these data provide a useful foundation for future research, providing good field efficacy information on the seasonal and long term changes in fungicide performance as well as a baseline to compare new fungicides.

Results were reported in a Scottish Government funded Technical Note entitled 'Barley Disease Control'. This note placed the appropriate dose data in a practical context of managing barley diseases. More effective ways of getting the information across to growers were developed as part of a Fungicide Performance Dose Curve Generator. Therefore a web-based tool allows growers to compare dose curves generated from seven years' study of different fungicides.