Zorvec™ active application advice for 2024
Corteva confirmed that a single sample containing a mutation with the potential to confer OSBPI resistance has been detected in the UK as part of the Corteva fungicide monitoring programme. This was identified during a DNA extraction of a bulk foliar sample taken from an untreated plant (it was impossible to isolate the specific strain from this bulk sample). While this is of note, there was no field impact on oxathiapiprolin performance either in the field crops or indeed in any neighbouring trials where intensive disease monitoring would have shown any variation in fungicide performance. Corteva Agriscience have a robust monitoring programme in place and have introduced a clear set of best practice guidelines outlined below. Adoption of this guidance should help UK growers and agronomists minimise the potential for selecting OSBPI resistant strains and thus maintain the efficacy of Zorvec products for the longer term.
Best practice application advice for 2024
· Apply Zorvec products in strict alternation with effective chemistry of a different mode of action, other than CAA (benthiavalicarb, mandipropamid, dimethomorph)
· The post-Zorvec application interval to the following non-Zorvec containing spray should not exceed 7 days.
· In curative situations (disease evident or confirmed in local area) Zorvec co-formulations should be applied in tank-mix with a partner fungicide containing a curative active ingredient e.g. cymoxanil or propamocarb.
· Sprays containing Zorvec should not exceed 20% of the total number of sprays applied to a crop.
· 2 sprays per crop if the expected programme is less than 15 sprays.
· A single crop should not receive more than 3 spays containing Zorvec products.
· Whilst still available, tank-mixing Zorvec products with mancozeb is recommended.
Additional for seed crops & home saved seed
· Zorvec applications must always be applied with a full rate of a curative fungicide e.g. cymoxanil.
· A single crop should not receive more than 2 sprays containing Zorvec products and these 2 sprays should not exceed 20% of the total late blight programme.
Products containing Zorvec™ active deliver highly effective disease control against potato Late Blight.
Zorvec remains a highly effective product for the control of Late Blight.
Corteva have a robust monitoring programme in place for the UK & Ireland, but no breakdown of efficacy to Zorvec in the field has been found.
Mancozeb remains registered in the UK and is a useful anti-resistance tank-mix partner.
Corteva strongly advise following the 2024 application advice when recommending and applying Zorvec products.
Corteva potato fungicides containing Zorvec™ active registered for use in the UK: Zorvec Endavia, Zorvec Entecta
USE PLANT PROTECTION PRODUCTS SAFELY. Always read the label and product information before use. For further information including warning phrases and symbols refer to label.
© 2024 Corteva.