The researchers studied the levels of hormones in eggplants to understand how they affect fruit development. They found that the parthenocarpic eggplant had higher levels of certain hormones before flowering, which helped in fruit development. Specifically, higher levels of IAA and ABA were beneficial for fruit development before flowering, while higher levels of IAA and GA3 and lower levels of ABA were beneficial after flowering. This balance of hormones plays a role in regulating fruit development in eggplants.