Planting Date Responses of Maturity Group III, IV, and V Soybeans in Northeast Louisiana.

In response to increased interest in early planting and a lack of pertinent experimental data, a soybean planting date study was continued in Northeast Louisiana in 2008. The experimental design was a split split plot factorial.  The whole plots were seven planting dates ranging from mid-March to late May or early June.  Split plots were two interrow spacings, a 40-inch spacing and a spacing that averaged 20 inches.  Split split plots were varieties, including two from Maturity Group III, three from Maturity Group IV, and one from Maturity Group V. The soil was Sharkey clay (Very-fine, smectitic, thermic Chromic Epiaquerts). The study was irrigated.  Data to be discussed include stand establishment, yield, and timing of maturity.