New Fungicide for Vegetables – Vegetable Crops Hotline

New Fungicide for Vegetables

New fungicide – I would like to announce the release of a new fungicide, Orondis® from Syngenta. It is a good product and should help commercial vegetable growers in combating downy mildew of cucurbits, Phytophthora blight of cucurbits, peppers and tomato, Buckeye rot of tomato and late blight of potato and tomato. However, I also want to discuss Orondis® because of the complicated way in which it is being released. Be advised that the listing for Orondis® in the MW Vegetable Production Guide for 2016 (ID-56) is incorrect. Please see the on-line version of the ID-56 for the most current information.

Orondis® has a new active ingredient which does not appear in any other fungicide and a novel mode of action, FRAC code U15. But you will not be able to purchase Orondis® on its own. It will be available as 3 different multi packs or co-packs. Each multi-pack will contain two jugs, each with a different active ingredient and mode of action. The products in the multi-pack are intended to be used as a tank mix. The correct use of the products will help to prevent the emergence of strains of the pathogens that are resistant to FRAC group U15. See Table 1 below for details.

This blog discusses the use of Orondis® products with cucurbits and solanaceous crops because I believe that Orondis® should have the greatest impact on these crops. However, many other crops are listed on the Orondis® label. For more details, check with Syngenta, your local chemical representative or me.

Table 1: Orondis® products will be available in 2016 as multi-packs. That is, growers will purchase a box with 2 different jugs. Each jug contains a different fungicide. Mix both products together as a tank mix in water for application. Follow the rate information on each product. Use the most restrictive REI and PHI* for each product in a multi-pack. After using one of the Orondis® products, alternate to a product with a different mode of action. Do not apply a foliar application of an Orondis® product after a soil application of an Orondis® product. That is, use soil or foliar applications of Orondis®, but not both.

Name of multi pack Products in multi pack (REI) Common name of a.i. (FRAC code) Crops (PHI) Rates
Orondis opti Orondis Opti A (4) Oxathiapipropilin (U15) Cucurbits (0) 2-4.8 fl. oz/A
Pepper (0)
Tomato (0)
Potato (5) 1.6-4.8 fl. oz/A
Orondis Opti B (12) Chlorothalonil (M) Cucurbits (0) 2 pts/A cucurbits
Pepper (3) 1.5 pts/A
Tomato (0) 2 pts./A
Potato (7) ¾ pts/A
Orondis Ridomil Gold SL** Orondis Gold 200 (4)*** Oxathiapipropilin (U15) Cucurbits (0) 2.4-19.2 fl. oz.
Pepper (0)
Tomato (0)
Ridomil Gold SL (48) Mefenoxam (4) Cucurbits (5) 1-2 pts/A
Pepper (7) 1 pt/A
Tomato (7) 1-2 pt/A
Potato (14) 3.2 fl oz./A
Orondis Ultra Orondis Ultra A (4) Oxathiapipropilin (U15) Cucurbits (0) 2-4.8 fl. oz
Pepper (0)
Tomato (0)
Potato (5) 1.6-4.8 fl. oz/A
Orondis Ultra B (4) Mandipropamid (40) Cucurbits (0) 8 fl oz/A
Pepper (1)
Tomato (1)
Potato (14)

* PHI=Pre-harvest Interval in days; REI=Restricted Entry Interval in hours.

**Orondis Ridomil Gold SL may only be applied to soil.

***Orondis Gold 200 is not labeled for potato.

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