The area was in financial trouble, and a boy did some research and found out that eggplants would grow well there. Tall triplet boys (they were French?) learned to play basketball, the team got new eggplant-colored jerseys, and the big game or tournament was won for eggplant publicity. The boys referred to a basketball while they were practicing and playing, saying things like, “Pass me the eggplant” or “Throw the eggplant.” They were trying to persuade farmers to plant eggplants, I think, and maybe trying to get publicity for the town. I think the cover art was an eggplant dropping into a basketball hoop.
My brother figured it out. I was a Teenage Hero by Robert C. Lee. McGraw Hill, 1969.