Maturity Group (MG) II soybean varieties have performed well in University of Kentucky tests over the past several years. Early planted (late April/early May) tests in the relatively dry years of l986 through 1989 showed MG II yields to exceed those of MG III or MG lV. Over the generally wetter years 1990 through 1993, MG III and lV yields were slightly better than those of MG II varieties. Across eight years of data, MG II yield averages were virtually identical to those of MG III and lV. Perhaps growers could plant a portion of their soybean acreage to MG II varieties and gain the advantages of earlier harvest, such as more fall planting options and slightly higher early fall cash market prices, while obtaining similar yields as they could with MG lV varieties.
Steele, Colleen C.; Grabau, Larry J.; and Gift, N., "On-Farm Testing of Early Maturing Soybean" (1995). Agronomy Notes. 31.