He saw his business explode in 2010, thanks in part to growing sales of vehicles made by the Indian manufacturer Mahindra. Mr. Topping is now teamed up with the company and is president of Southeast Mahindra, where nearly 60 people assemble and distribute small red tractors suited to gentleman farmers.

The parts are made in the United States as well as India, South Korea and Japan. “Everything has foreign content,” he said.

Production workers at Southeast Mahindra start at a wage of $12 an hour, eventually earning up to $20 an hour. The competition with rivals, both in the United States and in developing countries, can be brutal, and success is counted in nickels and minutes. Like other Southern states, Tennessee makes a selling point of the scarcity of unions, largely a result of laws exempting workers who don’t join from paying the equivalent of dues.

“It’s hard work,” Mr. Topping acknowledged as the temperature outside neared 97 degrees, making the air in the assembly shed hot and thick. “But this is a close-margin business,” he said, explaining why he is not offering more money despite adding a second shift.