PTAB

IPR2013-00022

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 ’989 patent discloses a method for enhancing the seed vigor of maize (corn) plants. The method involves reducing the functional leaf area of the plants (defoliation) within a specific timeframe after pollination, measured in Growing Degree Days (GDDs), and then harvesting the seeds.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1 and 2 - Claims 1 and 2 are anticipated by Hunter under 35 U.S.C. §102(b).

  • Prior Art Relied Upon: Hunter (James L. Hunter's doctoral dissertation, "Relationship between the Stage of Corn Seed Maturation and Assimilate Supply, Assimilate Uptake, and Seed Quality," June 1989).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Hunter disclosed every element of claims 1 and 2. Hunter taught a method of treating maize plants by mechanically removing all leaf blades (defoliation) to accelerate maturation and enhance seed vigor. Based on weather data and known pollination timing, Petitioner calculated that Hunter’s defoliation at 20 and 21 days after pollination corresponded to approximately 515-579 GDDs. Petitioner contended that this range anticipated the claimed range of "between about 600 and about 850 GDDs" when considering the inherent imprecision of GDD calculation and the broadening effect of the term "about." Hunter also explicitly disclosed that this defoliation treatment resulted in enhanced seed vigor, as measured by cold tests, relative to undefoliated control plants.

Ground 2: Anticipation of Claims 1 and 3-5 - Claims 1 and 3-5 are anticipated by Alcantara under 35 U.S.C. §102(b).

  • Prior Art Relied Upon: Alcantara (Alcantara and Wyse's article, "Glyphosate as a Harvest Aid for Corn (Zea mays)," Weed Tech. 2:410-413 (1988)).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Alcantara inherently anticipated claims 1 and 3-5. Alcantara evaluated glyphosate (Roundup®) as a chemical defoliant to enhance corn kernel dry down. Petitioner calculated that Alcantara's application of glyphosate occurred at approximately 794-921 GDDs after pollination, which Petitioner argued fell within the broadest reasonable interpretation of the claimed "about 600 and about 850 GDDs" range. Although Alcantara did not expressly measure seed vigor, Petitioner argued that because Alcantara performed the same steps as claimed (defoliation within the specified GDD window followed by harvesting), the resulting seed assemblage would necessarily have had enhanced vigor. Alcantara’s use of glyphosate, a chemical herbicide, was argued to meet the limitations of dependent claims 3-5.

Ground 3: Obviousness of Claims 1-5 - Claims 1-5 are obvious over Hunter in view of Major under 35 U.S.C. §103.

  • Prior Art Relied Upon: Hunter (1989 doctoral dissertation) and Major (DJ Major's article, "Effect of Simulated Frost Injury Induced by Paraquat on Kernel Growth and Development in Corn," Can. J. Plant Sci. 60:419-426 (1980)).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that Hunter taught mechanical defoliation of maize at approximately 515-579 GDDs to enhance seed vigor. Major taught chemical defoliation of maize using paraquat at approximately 550-700 GDDs to simulate frost injury. Petitioner contended that the GDD ranges in both references were close enough to the claimed range to suggest the same property of enhanced seed vigor.
    • Motivation to Combine: A POSITA would combine Hunter and Major because Major disclosed a well-known chemical defoliant (paraquat) that was a predictable and effective substitute for Hunter's mechanical defoliation method. Both methods were known in the art to perform the same function of reducing functional leaf area.
    • Expectation of Success: A POSITA would have a reasonable expectation of success in achieving enhanced seed vigor by substituting Major's chemical method for Hunter's mechanical one. Since both references disclosed defoliation in similar GDD windows and Hunter explicitly showed enhanced vigor, a POSITA would expect the predictable substitution of a chemical defoliant to yield the same successful result.

  • Additional Grounds: Petitioner asserted numerous other grounds, including anticipation of claims 1-2 over Vasilas (a 1986 journal article); obviousness of claims 1-5 over Vasilas in view of Alcantara; and obviousness of claims 6-7 by further combining the primary references with Patent 5,491,125, which taught the use of specific herbicides (Ignite®) and surfactants.

4. Key Claim Construction Positions

  • "between about 600 and about 850 GDDs after pollination": Petitioner argued this phrase should be given its broadest reasonable interpretation to encompass GDD values well outside the recited 600-850 endpoints. This argument was based on several points of alleged imprecision:
    • The use of the imprecise qualifier "about" at both ends of the range.
    • The existence of two different GDD calculation methods (capped and uncapped) known to a POSITA.
    • The inherent variability in determining the precise start date for GDD counting (e.g., "full silk" vs. "three days after full silk").
    • The lengthy duration (2-4 days) of the defoliation process itself, during which GDDs continue to accumulate.
  • Petitioner contended that, taken together, these factors would lead a POSITA to understand the claimed range as encompassing values from at least 515 to 921 GDDs, thereby covering the disclosures in the prior art.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-7 of the ’989 patent as unpatentable.