Evaluation location: Mississippi, United States
Accessions in maturity groups V through VIII, PI 593948 to PI 594904 (received between 1995 and 1996) were evaluated for descriptive characteristics, agronomic performance, and seed composition in Stoneville, Mississippi (Lat. 33o 26' N). Also included were cultivars in the same maturity groups, developed at public institutions in the United States and Canada, and released by 1997 and some accessions received earlier which had not been previously evaluated. All tests were replicated once per year. Plots were four rows wide, with rows 3.6 m long and 76 cm between rows and blocked by maturity group. Only the center two rows of each plot were harvested for yield. All accessions were planted again in single rows in 2004 to verify plant descriptors. Planting dates were May 18, 1998 and May 14, 1999. Plants flowered an average of 8 days later and matured 5 days later in 1998 than in 1999. Yields were generally greater in 1999 than in 1998. Seed quality, seed mottling, seed shape, and chemical analysis of maturity group VIII accessions were not recorded in 1998 due to extremely poor seed quality. Seed composition was analyzed at the USDA Northern Center for Agricultural Utilization Research in Peoria, IL. Fatty acid composition was obtained by gas liquid chromatography of the methyl esters (Christie 1989; Bannon et al. 1982). Oil and protein for samples with yellow seed coats were analyzed using the near infrared method for whole-grain analysis (AACC Method 39-21). Protein concentrations for samples with colored or heavily mottled seed coats were obtained using the improved Kjeldahl method (AACC Method 46-16) and oil by the Butt Extraction method (AOCS Official Method Ac 3-44).