Soybeans (Glycine max) can be planted along the upper Texas Gulf Coast from mid-March through May to take advantage of early season rains and to complete harvest before hurricane season and fall rains become a problem. When average to above average rainfall was received in May through July, yields were greater with the early April to mid-April planting; however, under high rainfall conditions throughout the season, the mid-April to early May planting produced the highest yields, with yields of over 4000？kg/ha. When rainfall was below normal, late March to early April plantings produced the greatest yields. When rainfall was above average, soybeans took longer to reach harvestability regardless of cultivar or plant dates, while under drought conditions the interval between planting and harvest was reduced. However, when planting was delayed, there was a greater risk of detrimental late-season effects from southern green stink bug (Nezara viridula) or the brown stink bug (Euschistus heros). 1. Introduction Soybeans (Glycine max) are grown along the upper Texas Gulf Coast and this area has become the largest soybean production area in the state. Most of the soybeans are planted from mid-March through May and are categorized as early soybean production system (ESPS) plantings. Production components such as planting date and variety can be manipulated to counter the effects of various environmental factors on soybean development and yield [1–5]. The rationale for planting early is to avoid reproductive growth during periods of high temperatures in July and August, and to take advantage of late spring and early summer rains for maximum flowering, seed set, and seed filling [4, 6]. Stress can reduce soybean yield by reducing the number of pods, seeds, and seed mass [7, 8]. Both determinate and indeterminate soybean cultivars have reduced growth rates under drought stress and resume normal growth rates when such stress is removed [8]. This may be an important growth attribute to consider if producers expect considerable soil moisture deficits due to short, intermittent droughts during the growing season [5]. The objectives of this research were to identify the components of soybean production encompassing cultivar and planting date that could increase soybean yield along the upper Texas Gulf Coast depending on moisture conditions. This information will aid producers in adapting planting practices that will improve soybean yield and reduce the chance of yield reductions. 2. Materials and Methods 2.1. Field Studies Field experiments were conducted in 2006 thru
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