Companies Clash Over Technology

December 8, 2012 01:03 PM

Dow AgroSciences LLC, a subsidiary of the Dow Chemical Company, has prevailed in its motion for summary judgment in a key patent infringement lawsuit involving its Enlist weed control system.

In a ruling by the U.S. District Court for the Middle District of North Carolina, two affiliates of Dow Agro-Sciences received a $5.3 million award against Bayer Bioscience. The lawsuit pertained to the Bayer Bacillus thuringiensis biotechnology patents. The patents were found in multiple legal proceedings to be unenforceable due to what the court described as Bayer’s "inequitable conduct."

The lawsuit was originally filed in 1995 by Plant Genetic Systems, a subsidiary of Bayer Bioscience.

Dow AgroSciences says the multimillion-dollar award will be used to cover attorneys’ fees and costs incurred by its affiliates.

Bayer says it strongly disagrees with the decision by the U.S. District Court and has filed an appeal.

Carryover Concerns

Herbicide carryover is something you’ll want to give thought to as you plan for the 2013 crop season, according to Iowa State University weed science Extension specialists Mike Owen and Bob Hartzler. They say drought conditions reduce the ability of corn and soybean herbicides to control weeds. In addition, due to low moisture levels, many weed control products were unable to adequately degrade in the soil. The net effect: there’s potential for crop damage from herbicide carryover in your fields next spring.

Fortunately, only a few of the herbicide active ingredients have characteristics that might lead to carryover problems in 2013, report Owen and Hartzler.

The products listed as "high risk" have the potential to damage rotational crops under normal conditions. "Most farmers have learned what rates can be used on their soils safely, but this year’s drought will result in a high risk even with reduced rates," say the Extension specialists. "Both chlorimuron and atrazine are more persistent in high-pH soils. Pre-emergence applications of chlorimuron will have a higher risk of problems because these rates are much higher than when chlorimuron is applied postemergence. The best option might be to alter rotation plans to avoid planting a susceptible crop."

Products listed as "moderate to slight risk" have been known to occasionally cause problems or have half-lives that suggest they might cause problems under abnormal onditions. Risks with these products will vary depending on specific field conditions.

"Keep in mind that if rainfall returns to normal, this rain will have much less effect on herbicide degradation than had it occurred near the time of herbicide application," the specialists add. "Also, while tillage should dilute herbicide residues in the soil, past experience has shown that this practice does not consistently reduce crop injury from herbicide residues. Using practices that minimize additional stresses to the seedling (planting date, seedbed conditions, etc.) can reduce problems associated with low concentrations of herbicides."

Factors Determining Risk of Carryover Injury

  • herbicide half-life

  • rate of herbicide applied

  • application date

  • soil characteristics (texture, organic matter, pH)

  • rainfall (total amount and distribution throughout year)

  • sensitivity of rotational crop

  • growing conditions following planting next spring

Herbicides with Carryover Potential

High Risk

  • atrazine
  • chlorimuron (Authority XL, Canopy, Envive, Valor XLT, others)
  • imazaquin (Scepter)
  • simazine (Princep, others)

Moderate to Slight Risk

  • fomesafen (Reflex, Flexstar, Prefix)
  • clopyralid (Hornet)
  • cloransulam (FirstRate, Hornet, Gauntlet)
  • imazethapyr (Pursuit)


  • pendimethalin (Prowl, others)
  • trifluralin (Treflan, others)

HPPD Inhibitors

  • isoxaflutole (Balance Flexx)
  • mesotrione (Callisto, Lumax, Lexar)
  • tembotrione (Laudis, Capreno)
  • topramezone (Impact)
Back to news


Spell Check

No comments have been posted to this News Article

Corn College TV Education Series


Get nearly 8 hours of educational video with Farm Journal's top agronomists. Produced in the field and neatly organized by topic, from spring prep to post-harvest. Order now!


Market Data provided by
Brought to you by Beyer