Tuesday, November 6, 2007 - 11:30 AM
141-8

Soybean Canopy Architecture Affect on Soybean Population and Grain Yield.

Shawn Conley, Nicole Fink, and Judith Santini. Purdue University, 915 W. State Street, Department of Agronomy, West Lafayette, IN 47907-2054

As soybean [Glycine max L. (Merr.)] input costs continue to increase growers search for areas where costs can be minimized.  Soybean seeding rate is a common target.  The objective of this study was to quantify the affect of soybean population and soybean stem architecture on grain yield and composition.  Research was conducted at six locations in 2005 and four locations in 2006 across Indiana.  The experimental design was a randomized complete block factorial design with four replications. The whole-plot factors were soybean population (123,500, 247,000, 370,500, 494,000, and 617,500 plants ha-1) and soybean stem architecture (bush vs. erect stem).  Two locally adapted bush and two erect soybean varieties were drilled in 19 cm rows at each location.  Plots measured 3 by 7.6 m.  Our preliminary results indicated that stem architecture did not affect grain yield or composition.  Our results also indicated that grain yield and composition was similar among all populations at 247,000 plants ha-1 or greater.  These results suggest that stem architecture is not an important factor to consider when planting soybean at reduced populations.  Our results also indicate that soybean stands of 247,000 plants ha-1 or greater will maximize soybean yield.