2005 Annual Report 4d.Progress report. This report serves to document research conducted under a Specific Cooperative aAgreement between the ARS and the Mississippi Agricultural and Forestry Experiment Station of Mississippi State University. Additional details of research can be found in the report for the parent research project 6402-21000-004-00D entitled, "Develop soybean genotypes and management systems for early season and stress environments." Experiments with soybean that involved planting date, early-season flooding, seed treatment, and double-cropping were conducted. Soybean cultivars of late maturity group (MG) III to late MG V maturity were planted from late March to early June. The best planting dates in 2004, based on yield, were late March through April, except there were no significant differences in yield among planting dates for MG III. Treating soybean seed with fungicide increased seed yield in 2004. Flooding plantings before seedling emergence or at the V1 growth stage did not affect seed yield regardless of time or duration (18, 24, and 48 hours) of flooding. Double-cropping experiments in 2003 showed lower yield of the double-cropped soybean compared to full season soybean. However, returns from high wheat yields more than offset the loss of soybean yield, resulting in higher net returns for the double-crop system. An internet-based database (DELTASOY) has been completed, and allows producers to access information from soybean variety trials conducted in the Midsouthern USA. It has been adopted by the Mississippi State University Extension Service as an application tool for soybean producers. The database can be accessed at http://msucares.com/deltasoy or http://www.deltasoy.msstate.edu.