They may be young, but these high school students already command the attention of major corporations.

National FFA members wearing their trademark blue jackets from chapters in all 50 states, as well as Puerto Rico and the Virgin Islands, are converging on Indianapolis for the organization’s 86th annual convention, which runs Wednesday through Saturday.

With more than 53,000 members sporting similar apparel, the convention is perhaps the most visible gathering the city hosts. More important, it’s also the largest in terms of both attendance and visitor spending.

The event is expected to generate more than $40 million for Indianapolis, putting it on par with a Final Four, said Chris Gahl, spokesman for the Indianapolis Convention & Visitors Association.

“Demographically, you can tell that even though they’re students, they’re important attendees,” he said. “Just look at the exhibitor list.”

Indeed, the booths of major universities and large corporations such as General Motors Corp., John Deere and Wrangler fill the Indiana Convention Center, vying for their attention.

The number of exhibitors this year, 375, held steady from last year’s FFA convention, as did attendance. That’s a testament to the organization, Gahl said, given that declines in conference attendance and exhibitor interest are prevalent in the tepid economy.

Craig Hansen, an executive with John Deere’s techology program, said the farm machinery manufacturer has sponsored FFA events for several years.

“Our equipment is not getting less complex; it’s getting more complex,” he said. “So we need qualified technicians to work on it, and we see several of our future technicians here.”

FFA has held its annual meeting in Indianapolis since 2006. But its roots in the city extend a bit deeper. The organization here moved from Alexandria, Va., in 1999, lured by a more central location and city incentives, said Dwight Armstrong, FFA’s chief operating officer. Its headquarters is near West 86th Street and Zionsville Road, a stone’s throw from the Trader’s Point shopping center on the northwest side.

In 2013, the convention will move to Louisville for a three-year stint and will return to Indianapolis in 2016 for another three years. Louisville then will get the first option of hosting the convention the following three years.

Louisville hosted the convention from 1999 to 2005 before it was moved to Indianapolis in 2006; Kansas City had it in prior years.

Indianapolis has a more convenient set of venues downtown and nicer hotels than Louisville, organizers say. However, Indianapolis hotels are more expensive than those in Louisville—raising costs to the point FFA officials suspected attendance was being hurt.

“Both cities offer advantages to our organization and to our students,” Armstrong said.

ICVA is working to fill the void the National FFA will leave in the city’s October convention calendar. It has a commitment for one of the three years between 2013 and 2015 from a major organization “that’s on par with FFA,” said Gahl, who wouldn’t release details about the replacement.

National FFA’s absence from Indianapolis in 2013 undoubtedly will be noticed. Its convention occupies four venues throughout the city—the convention center, Lucas Oil Stadium, Conseco Fieldhouse and the Indiana State Fairgrounds.

The convention center hosts an agricultural career show and career development workshops, while events such as horse, livestock and poultry evaluations are held at the fairgrounds.

Several sessions are slated for the fieldhouse, where speakers will address the students and awards will be presented. About 400 student delegates from across the country will discuss issues important to agriculture.

Students on Wednesday evening will be treated to a concert at Lucas Oil Stadium by popular country music group Lady Antebellum.

Founded in 1928, FFA’s origins are tied to farming. But Armstrong hopes Indianapolis residents realize the organization, which shelved the Future Farmers of America name in 1988, offers much more.

Members are likely to pursue high-tech careers in such fields as biology, chemistry or engineering, for instance.

“The city itself embraces us and knows who we are,” Armstrong said. “But I’m sure there are those who think of us as, ‘Oh, those are the farm boys.’”

FFA has more than 523,000 members and boasts an annual budget of about $20 million.