Tests were planted at eight locations across the state. Two tests were located in the Tidewater in Washington and Beaufort County on organic soil (HM). In the Coastal Plain region, four tests were conducted in Columbus, Robeson, Lenoir, and Duplin counties. In the Piedmont, two tests were conducted in Rowan and Union county. Early, medium and full-season groups were included at all locations. Early-maturing hybrids are approximately 105 - 109 days to maturity, medium-maturing hybrids are approximately 110 - 115 days to maturity, and full-season hybrids are approximately >115 days to maturity. It is important to remember that these are loose groupings, i.e some hybrids may easily fit into either of two maturity groups. Seed companies listed the number of days to maturity for each hybrid. Table 2 lists the cultural practices used and Table 3 lists the soil tests results. Field trials were designed in a randomized complete block for each maturity group. Each plot consisted of two rows 22 feet long with a 30, 36, or 38" row width, depending on location. The two rows were harvested for yield. Alley width was six feet.
In 2013, all hybrids were planted at the same population within maturity group. The early hybrids were 34,000 ppa while medium and late hybrids were 32,000 ppa. All hybrids were treated with Poncho (clothianidin) or Cruiser (thiamethoxam) or other systemic insecticides (Table 13).