In order to further understand the effect of application timing of mepiquat chloride (MC) on cotton yield, we reviewed data collected from our experiments conducted 1996 - 1999 in Corpus Christi, Texas. All tests were irrigated randomized complete block design and received MC applications based on height-to-node ratio at the time of treatment. All experiments were planted with either Deltapine 5409 or Deltapine 33B and grown in a Victoria clay soil on 38-inch spacing. Applied amounts of MC were calculated by the MEPRT software that takes plant size into account. Weather data was collected on an hourly basis.