Attorney advertising. This article is general information, not legal advice.

If you develop crop-protection products, seed treatments, or other crop inputs, a recent Federal Circuit decision is a reminder that the most dangerous prior art may not be a U.S. patent at all. On October 14, 2026, in Syngenta Crop Protection AG v. UPL Ltd., Nos. 2025-1018, -1019, the court affirmed a Patent Trial and Appeal Board decision holding every claim of UPL’s U.S. Patent No. 11,445,727 unpatentable. One of the key references was a Brazilian technical circular on soybean rust trials.

The decision is nonprecedential, so it doesn’t bind future panels. Judge Taranto wrote the opinion for a panel that also included Judges Hughes and Cunningham. The reasoning is still worth a close look for anyone building a patent portfolio around fungicide mixes or other product combinations.

The patent and the challenge

UPL’s ‘727 patent covers fungicidal combinations. Claim 1 claims a combination “consisting of” benzovindiflupyr (an SDHI fungicide), mancozeb (a dithiocarbamate), and at least one more fungicide from a listed group of EBI or QOI fungicides. Claim 2 requires one fungicide from each of those groups. The patent also reported field trials said to show a synergistic effect from adding mancozeb.

Syngenta, a competitor, petitioned for post-grant review (PGR2023-00017) in January 2023. Post-grant review is available only during the first nine months after a patent issues, but it allows a broader set of challenges than the more familiar inter partes review. In its July 2024 final written decision, the Board held all challenged claims unpatentable:

• most of the claims were anticipated by Godoy, a 2016 Embrapa Soja (Brazil) publication summarizing cooperative trials of fungicides against Asian soybean rust;
• most of the claims were also anticipated by Tobler, U.S. Patent No. 9,314,022; and
• claim 2 was obvious over an earlier WO publication (De Oliveira) in view of a published abstract, Godoy, and Tobler.

UPL appealed, and the Federal Circuit affirmed on every ground.

The “consisting of” fight

“Consisting of” is the narrowest transition phrase in claim drafting. It closes the claim to unlisted ingredients. The parties agreed it meant the claimed combinations include the recited fungicides “and no other fungicides.” UPL used that narrowness as a shield and made two arguments.

First, UPL argued that a reference can’t anticipate a “consisting of” claim unless it affirmatively says other ingredients are excluded. The court rejected that as a rule of law. What a reference discloses is a factual question, and even a reference written in open “comprising” language can disclose a combination of just the listed components.

Second, UPL pointed out that Godoy’s treatments included an extra product, Nimbus. If Nimbus were a fungicide, Godoy would describe four fungicides, not the claimed three. But the Board found, based on Godoy’s own active-ingredient list and other evidence identifying Nimbus as a mineral oil, that Nimbus as used in Godoy was not a fungicide. The Federal Circuit held that finding was supported by substantial evidence. So an added non-fungicide product didn’t keep the prior art outside the claim.

Tobler was a different kind of reference: a U.S. patent describing many possible combinations. UPL argued that Tobler’s long lists didn’t really disclose its specific mix. The court disagreed, because Tobler expressly named the claimed combination and flagged azoxystrobin as especially suitable.

The cross-appeal: field-trial data and sanctions

Syngenta suspected that the field trials reported in the patent never took place. Two days before the final decision, it asked for leave to move for sanctions. The Board said no, because six months earlier UPL had expressly withdrawn any reliance on the patent’s field-trial examples. The Federal Circuit affirmed, reading the PTAB sanctions rule (37 C.F.R. § 42.11) to give a party that withdraws a challenged position a safe harbor. The court didn’t find that the trials were fabricated or that they were real. It decided only that the Board didn’t abuse its discretion.

Takeaways for ag-chem and crop-input innovators

• Search foreign and agronomic literature, not just patents. Extension bulletins, cooperative trial reports, and foreign-language technical circulars can be prior art. A Brazilian soybean-rust circular helped invalidate a U.S. patent here.
• “Consisting of” is not a force field. Narrow claims can still be anticipated if the art discloses the same actives. Adjuvants, carriers, and surfactants may not count as an extra “fungicide,” depending on how the claim is written.
• Draft for the ingredients that actually matter. Think carefully about whether the claims should exclude other actives, other fungicides, or anything at all, and support each version in the specification.
• Expect post-grant review. Competitors in ag-chem watch new patents closely. A newly issued patent can be challenged on broad grounds within nine months.
• Data in a patent must be real and reproducible. Reported results invite scrutiny, and a competitor may run its own trials to test them.

Source: the Federal Circuit’s October 14, 2026 opinion (PDF).

For related reading, see our patents overview and what a patent costs in Iowa, including budgeting for searches before you file.

Talk with an Iowa patent attorney

Jason Sytsma is a registered patent attorney in Cedar Rapids who works with Iowa manufacturers, ag businesses, and inventors. Learn more on the About Jason page and the firm bio.

Contact the office to request a consultation. Any engagement is subject to conflicts review, an engagement agreement, and applicable professional-responsibility rules. This article is attorney advertising and is intended for general educational purposes only; it is not legal advice and does not create an attorney-client relationship. Results vary, and past experience does not guarantee a particular outcome.