1) Water deficits during maize flowering inhibit photosynthesis and cause kernel abortion when starch is depleted in the ovaries. 2) Low water potential decreases acid invertase activity in the ovaries, limiting sucrose breakdown and the carbon flow needed for kernel development. 3) Infusing sucrose during drought partially restores invertase activity and kernel development, but abortion is only partially prevented. Understanding the genetic factors influencing drought response could help develop maize varieties with improved drought tolerance during reproduction.