Resistance management guideline for anilinopyrimidine (AP) [Group 9] fungicides used against botrytis bunch rot (Botrytis cinerea) in wine grapes in New Zealand
(revised October 2014)
Objective of this guideline
- Maximise the useful life of AP fungicides for control of botrytis bunch rot (botrytis) in wine grapes in New Zealand by developing a resistance management guideline that is effective, easy to integrate into botrytis disease control programmes and able to achieve a high degree of guideline compliance.
Rationale
- APs are among the most effective fungicides for botrytis management in wine grapes and if B. cinerea developed resistance to them it would seriously compromise disease control in vineyards. Resistance risk is considered to be high.
- NZCPR guidelines for AP fungicides were last updated in December 2004 and need updating for botrytis to make them compatible with the increasing use of disease management products in wine grapes with low efficacy against botrytis.
- Resistance management relies on limiting numbers of applications of at-risk fungicides and mixing or alternating them with effective fungicides from different cross resistance groups.
- This resistance management strategy limits numbers of AP applications and uses mixing. Alternation is also recommended to avoid consecutive applications of APs.
- Natural products, biological control agents and some synthetic fungicides with low activity against B. cinerea are not suitable as mixing or alternation partners with APs for resistance management as they are not expected to provide any reduction in resistance selection pressure on the AP fungicides.
- Resistance management guidelines vary between countries due to different cropping practices, different availability of fungicides as mixing or alternation partners and to differences in the way resistance strategies are formulated, e.g., by pathogen, as for FRAC and NZCPR, or by crop as for CropLife Australia. Although New Zealand guidelines need to use sound resistance management practices, they do not need to comply exactly with overseas guidelines.
- This guideline has been prepared jointly by NZCPR, Sustainable Winegrowing New Zealand and the New Zealand agrochemical industry.
- These new guidelines are conservative in that they recommend mixing for in all AP fungicide applications. By adopting this conservative strategy it is intended to preserve the long term efficacy of these important botrytis fungicides.
Table 1: Anilinopyrimidine (AP) guideline for wine grapes Total number of botrytis-specific fungicide applications (excluding natural products and biological controls)1 Maximum number of AP applications3 Mixing4 Application rates in mixtures 1-6 botrytis-specific applications per season Max. 2 per season Always apply in mixture with another effective botrytis-specific fungicide, either as a co-formulated product or a tank mix In both co-formulated products and tank mixtures, either component on its own should provide an effective fungicidal dose against B. cinerea. Do not reduce rates of fungicides applied in mixtures. 7 or more botrytis-specific applications per season Max. 3 per season 1A botrytis-specific fungicide application contains one or more fungicide products with high activity against Botrytis cinerea. Biological control agents, plant defence elicitors and products whose primary effect is on plant nutrition do not have sufficient activity against B. cinerea to be considered botrytis-specific products. Some inorganic fungicides and older synthetic fungicides, which have low activity against B. cinerea, are not suitable as mixing partners for resistance management. See Sustainable Winegrowing New Zealand (SWNZ) product list below.
2SWNZ stipulates a maximum of six botrytis-specific fungicide applications per season. This maximum relates to sustainable viticultural practices and residue management and is not, in itself, a requirement for resistance management.
3Maximum number of applications containing an AP fungicide that must not to be exceeded each growing season. Note: Every application that contains an AP fungicide, including mixtures, is one count towards the season's AP total.
4A mixing partner must be a botrytis-specific fungicide from a different cross-resistance group, applied at a rate which on its own would provide effective control of botrytis bunch rot.
Table 2: Products listed by SWNZ with a claim for botrytis bunch rot control in grapes Product name Active ingredient Fungicide group
(for mixing with APs)Suitability as a mixing partner
in AP-containing applicationsAmistar azoxystrobin Quinone outside inhibitor (QoI) No Apex pyrimethanil + fluazinam Dintro-aniline Yes – this product contains an AP with a suitable mixing partner Armour-Zen chitosan No Botry-Zen Ulocladium oudemansii No Bravo chlorothalonil No Cabrio WG pyraclostrobin QoI No Captan captan No copper (various) various active ingredients No Diva, Ethpyri, Predict, Pyrus, Scala pyrimethanil AP No - these are all AP's Folio Gold metalaxyl-m + chlorothalonil No Gem, Nando, Pinnacle fluazinam Dintro-aniline Yes Max metalaxyl + chlorothalonil No MicroPlus Streptomyces lydicus No Pristine pyraclostrobin + boscalid QoI + SDHI Yes Protek carbendazim Benzimidazole No Protector fatty acid No Rovral iprodione Dicarboximide Yes Sentinal Trichoderma atroviridae No Serenade Max Bacillus subtilis No Sumisclex procymidone Dicarboximide Yes Punch, Renova, Savy, Switch cyprodinil + fludioxonil AP + phenylpyrrole Yes – these products contains an AP with a suitable mixing partner Teldor fenhexamid Hydroxyanilide Yes Teldor Scala Combi fenhexamid + pyrimethanil Hydroxyanilide + AP Yes – this mixture is an AP with a suitable mixing partner Teracep peracetic acid + hydrogen peroxide No Thiram thiram No
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