How does Trichoderma control downy mildews?
Trichoderma is an endophyte and needs to be applied to re-growth of rose plants (red leaves) after ﬂushing or pruning. Downy mildews are also systemic which makes them diﬃcult to control because they are not exposed to control agents. Systemic fungicides are more prone to resistance occurring and Trichoderma should be tank mixed when systemic fungicides are applied – as part of a resistance management programme. Weekly foliar applications of Trichoderma have provided good control of downy mildews in roses and onions. Do not spray to ‘run-oﬀ’.