Texas Gulf Coast Soybean Yield Affected by Soybean Variety and Planting Date

Soybeans (Glycine max) are planted along the upper Texas Gulf Coast from mid-March through May to try to take advantage of early season spring and summer rains and also to complete harvest before hurricane season and fall rains become a problem. These plantings are with maturity groups (MG) IV and V and are mainly grown under nonirrigated conditions. Under normal rainfall conditions (rainfall in April, May, and early June), this study shows that a late March or early April planting date provided the highest yield although a May plant date can result in yields of greater than 50 bu/acre if rainfall is received at the proper times. However, when planting was delayed, there was a greater risk of detrimental late-season effects from drought and southern green stink bug (Nezara viridula) or the brown stink bud (Euschistus heros). In 2004 and 2005, at both locations, soybeans planted at the early plant date took longer to reach physiological maturity than the later plant dates. Generally, the earlier the plant date, the greater number of days from planting till harvest.