12 top management tips to help slow fungicide resistance in septoria have been issued as part of the Fungicide Futures initiative
Yes – Poor practice can make septoria tritici more resistant in one season, so you will face a more resistant population next year. Collective action is required.
Yes – If it allows a less intensive fungicide programme to be used. It acts like an extra mixing partner.
No – If disease is kept lower by more intensive use of fungicides. Yes – If disease is reduced by cultural methods (eg resistant varieties and later sowing).
The SDHI should be mixed with an azole dose of comparable efficacy and a multisite.
No – Multisites are useful to protect azoles and SDHIs at all spray timings.
Yes – Although efficacy has reduced, epoxiconazole and prothioconazole still give good (50 to 60 per cent) control in a protectant situation and are vital to protect SDHIs.
Yes – There is a high level of cross-resistance, so mixing SDHIs is not a resistance management strategy
No – The strobilurin has low activity against septoria tritici and does not protect the SDHI.
Yes – Selection for azole-resistant strains happens whenever an azole is used, even if septoria tritici is at low levels and is not the target of the spray. If rust is the main target, a strobilurin is a good alternative.
Yes – Selection for azole-resistant strains happens whenever an azole is used, even if septoria tritici is at low levels and is not the target of the spray. Adding a multisite reduces risk.
Both – Mixtures and alternation are both good strategies to slow resistance. Mixtures are better in a wider range of situations and are required for some modes of action.
12. Can alternating azoles help slow resistance against azoles?
Yes – Alternating azoles may have a small beneficial effect.
Fungicide Futures is a joint initiative between AHDB and the Fungicide Resistance Action Group UK (FRAG).