“Expand or die.”

That ominous motto of Henry Whipple, a successful Iowa farmer in Ramin Bahrani’s new film, “At Any Price,” distills the business philosophy of a man driven by ambition. Henry, who farms more than 3,000 acres, is an aggressive, unscrupulous salesman for a company that markets genetically modified seeds. With a too-wide grin that threatens to crack the corners of his mouth and a backslapping friendliness that verges on obsequiousness, Henry is portrayed by Dennis Quaid as a warped caricature of a reassuring American archetype: the down-to-earth family man in the heartland with his feet firmly planted in the soil.

‘AT ANY PRICE’ Rated: R Opens today at Kahala 8

On one level “At Any Price” is a critical exploration of agribusiness and its cutthroat, hypercompetitive ways. On a deeper level it is a searching, somewhat ham-handed allegory of American hubris in the 21st century and a bleak assessment of the country’s wobbly moral compass.

Henry’s world is in danger of crumbling. He has a loyal, attractive wife, Irene (Kim Dickens), who tolerates his infidelities. And he has strained relationships with his two sons, the older of whom has signaled his lack of interest in the family business by fleeing the nest to climb mountains in South America.

Desperate for the business to remain in the family, as it has for four generations, Henry pressures his neglected younger son, Dean (Zac Efron), to show some enthusiasm for farming and eventually step into his shoes. But the focus of Dean’s life is stock car racing. Though he is a fierce, talented competitor with NASCAR dreams of glamor and glory, Dean is also a hothead who unleashes contemptuous tirades at his father. During a race at a regional track, he flies into a blind rage at a competitor. When he is injured in a crash, he abruptly turns his back on the sport.

The movie traces an emotional line of descent from Henry’s stern father, Cliff (Red West), who disapproves of his son’s lack of ethics, to the volatile Dean. Each generation has less self-control and patience than the one before.

In an unnecessary subplot intended to underline their weaknesses, both father and son avail themselves of the charms of a former cheerleader (Heather Graham). The arrogant, impulsive Dean doesn’t even bother to conceal the fling from his smart, pretty girlfriend (Maika Monroe).

“At Any Price” pays close enough attention to the world of high-tech farming to provide a rough outline of its challenges and stresses. It shows how Henry’s breed of go-getter freezes small farmers out of their livelihoods. In an uncomfortable scene that demonstrates his ruthlessness, he crashes another farmer’s funeral and buys his land right then and there. The movie addresses the copyrighting of seeds and their illicit use, a clandestine activity that Henry practices only to find himself under criminal investigation.

“At Any Price” obliquely refers to the controversies surrounding the ownership of genetically modified superseeds developed by corporations like Monsanto. There is no mention of global warming and the worsening drought in America’s breadbasket. Henry’s cornfields are picture-perfect and his harvests bountiful.

His major competitor, Jim Johnson (Clancy Brown), is a neighboring farmer with a son Dean’s age (Ben Marten), who also races cars and whom Dean hates with a venomous passion. The rivalry between these two clans lends the movie a threatening undertone of violence.

Bahrani, who wrote the screenplay with Hallie Elizabeth Newton, was born in Winston-Salem, N.C., the setting of his last film, “Goodbye Solo,” which was the third of his small, indie, neorealist gems studying people struggling on the lower rungs of the economic ladder.

At the two-thirds point, the movie makes a giant leap of faith with a far-fetched, manipulative plot twist that binds Henry and Dean together, whether they like it or not. This turn of events makes allegorical sense yet defies credibility. But if “At Any Price” overstates its points, they are still worth making. And the hot-wired performances by Quaid and Efron drive them home in a movie that sticks to your ribs and stays in your head.

© 2013 The New York Times Company