Vernon Hugh Bowman seems comfortable with the old way of doing things, right down to the rotary-dial telephone he said he was using in a conference call with reporters.

But the 75-year-old Indiana farmer figured out a way to benefit from a high-technology product, soybeans that are resistant to weed-killers, without always paying the high price that such genetically engineered seeds typically bring. In so doing, he ignited a legal fight with seed-giant Monsanto Co. that has now come before the Supreme Court, with argument taking place Tuesday.

The court case poses the question of whether Bowman's actions violated the patent rights held by Monsanto, which developed soybean and other seeds that survive when farmers spray their fields with the company's Roundup brand weed-killer. The seeds dominate American agriculture, including in Indiana where more than 90 percent of soybeans are Roundup Ready.

Monsanto has attracted a bushel of researchers, universities and other agribusiness concerns to its side because they fear a decision in favor of Bowman would leave their own technological innovations open to poaching. The company's allies even include a company that is embroiled in a separate legal battle with Monsanto over one of the patents at issue in the Bowman case.

The Obama administration also backs Monsanto, having earlier urged the court to stay out of the case because of the potential for far-reaching implications for patents involving DNA molecules, nanotechnologies and other self-replicating technologies.

Monsanto's opponents argue that the company has tried to use patent law to control the supply of seeds for soybeans, corn, cotton, canola, sugar beets and alfalfa. The result has been a dramatic rise in seed prices and reduced options for farmers, according to the Center for Food Safety. The group opposes the spread of genetically engineered crops and says their benefits have been grossly overstated.