PTAB

IPR2013-00023

Monsanto Co v. Pioneer Hi Bred Intl Inc

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1. Case Identification

2. Patent Overview

  • Title: Seed Vigor by Pre-Harvest Defoliation of Maize Plants
  • Brief Description: The ’974 patent discloses a method for obtaining a maize seed assemblage with enhanced seed vigor. The method comprises reducing the functional leaf area of, or defoliating, maize plants within a specific timeframe after pollination, measured in Growing Degree Days (GDDs), and subsequently harvesting the seeds from the treated plants.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1, 2, and 8-11 under §102 by Hunter

  • Prior Art Relied Upon: Hunter (a 1989 doctoral dissertation titled "Relationship between the Stage of Corn Seed Maturation and Assimilate Supply, Assimilate Uptake, and Seed Quality").
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Hunter disclosed every element of the challenged claims. Hunter described experiments involving the mechanical defoliation ("removal of all leaf blades") of maize plants to accelerate seed maturation and enhance seed vigor. Petitioner’s calculations, based on data and methods known in the art, showed Hunter’s defoliation occurred between approximately 515 and 579 GDDs after pollination. This range, Petitioner asserted, falls within the broadest reasonable interpretation of the claimed range of "between about 600 and about 850 GDDs." Hunter explicitly taught that this defoliation treatment resulted in the "development of maximum seed vigor" and provided data from cold emergence tests, a standard measure of vigor, showing improved results in defoliated plants compared to controls.

Ground 2: Anticipation of Claims 1, 2, and 8-11 under §102 by Vasilas

  • Prior Art Relied Upon: Vasilas (a 1986 journal article titled "Effect of Defoliating Corn Inbreds on Seed Quality").
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Vasilas also anticipated the claims. Vasilas disclosed experiments involving the mechanical defoliation ("imposed by hand") of corn inbreds at the milk stage. Using dates provided in a related publication by the same author (Vasilas '85), Petitioner calculated that this defoliation occurred at approximately 786 GDDs (capped formula) or 860 GDDs (uncapped formula) after pollination. Petitioner argued these values fall within the claimed range of "between about 600 and about 850 GDDs," especially considering the qualifier "about." Vasilas reported that cold germination results for defoliated treatments were higher than non-defoliated controls, directly teaching the claimed enhanced seed vigor.

Ground 3: Obviousness of Claims 1-5 and 8-11 over Hunter in view of Alcantara

  • Prior Art Relied Upon: Hunter (1989 dissertation) and Alcantara (a 1988 journal article titled "Glyphosate as a Harvest Aid for Corn").

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that Hunter taught mechanical defoliation of maize at a GDD range (515-579 GDDs) very close to the claimed range to achieve enhanced seed vigor. Alcantara taught chemical defoliation using glyphosate (Roundup®) as a pre-harvest treatment to enhance corn kernel dry down, with applications calculated to be within a range of 794-921 GDDs after pollination. This established that using defoliants for pre-harvest treatment of maize was known in the art.
    • Motivation to Combine: A POSITA would combine Hunter and Alcantara because Alcantara taught the use of a chemical defoliant (glyphosate) to achieve results related to seed maturation, making it a well-known and predictable substitute for the mechanical defoliation method taught by Hunter. The motivation was to use a more efficient, large-scale method (chemical spraying) to achieve the same known benefit (enhanced seed vigor/maturity) disclosed by Hunter.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because both references operated in the same technical field (pre-harvest treatment of maize) to achieve related goals (enhanced vigor or maturation). Since Hunter demonstrated the principle that defoliation in a specific GDD window enhances vigor, a POSITA would expect that applying a known chemical defoliant from Alcantara within a similar window would predictably yield the same result.

  • Additional Grounds: Petitioner asserted numerous additional anticipation and obviousness challenges. These included anticipation of claims 1 and 3-5 by Alcantara and Major (a 1980 journal article on chemical defoliation with paraquat). Obviousness grounds included combinations of Hunter with Major; Vasilas with Vasilas '85 (a related 1985 journal article); Vasilas with Alcantara; and Vasilas with Major. Further grounds added Albrecht (Patent 5,491,125) to teach other herbicides and surfactants.

4. Key Claim Construction Positions

  • Petitioner argued for a broad interpretation of the claim term "between about 600 and about 850 GDDs after pollination." This interpretation was central to nearly all grounds.
  • The argument was based on three points:
    1. The term "about" expands the numerical endpoints of the range.
    2. The underlying GDD measurement itself was inherently imprecise, with at least two known calculation methods (capped and uncapped) available to a POSITA that yield different results from the same temperature data.
    3. The patent specification was inconsistent regarding the precise start time for counting GDDs (e.g., from full silk vs. three days after full silk).
  • Collectively, Petitioner argued these factors would lead a POSITA to understand the claimed range as encompassing values well outside the literal 600-850 GDDs, including the lower values in Hunter (e.g., 515 GDDs) and higher values in Alcantara (e.g., 921 GDDs).

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-11 of the ’974 patent as unpatentable.