Planting Dates for Early-Maturing Soybean Cultivars

摘要: Early planting dates may not be required for successful culture of early-maturing soybean [Glycine max (L.) Merr.] at midlatitudes in the USA. The objectives this research were to evaluate cultivars southern environments, try identify cultivar characteristics contributing fit these into cropping system, and determine range that best discriminate among northern cultivars. Field trials, involving 12 Maturity Group (MG) II cultivars, planted late April mid-May, May early June, mid-June, mid-July on a Maury silt loam (fine, mixed, mesic Typic Paleudalf) near Lexington, KY, 1993 1994. Yield response date was consistent across years, showing yields mid-June plantings. Pioneer 9273 produced significantly more grain than all other Across years dates, lowest yielding (IA 2008) 19% less did 9273, emphasizing importance selection. Canopy closure ratings reproductive growth stages R2 or R5 somewhat better related yield plant mass (at R5) height. shortest had greatest stubble losses; producers want avoid such Identification high-yielding clearest first two dates. Perhaps performed well under cool, moist soil conditions favored by earlier Selection production south their traditional full-season areas appears done from southerly zone.