Evaluation of Soybean Varieties for Certified Organic Production⎯Neely-Kinyon Trial, 2006

Materials and Methods Varieties selected for the 2006 organic soybean variety trial included the following: Pioneer 9305, Blue River 3F43, Blue River 2FN93, Blue River 28YP5, MRK0431CTB, MRK0427CTA, and Schillinger 240F.Y. Plots measuring 20 × 90 feet were laid out in a completely randomized block design with four replications of each variety. Soybeans were planted at a depth of 2 inches on May 23, 2006, at a rate of 200,000 seeds/acre. Weed control was established through the following procedures: rotary hoeing on June 1 and June 14; cultivation on June 12 and June 27; and walking plots on June 29. Plant stands were counted on June 1314. Weed population data were taken on June 13-14 and June 26. Insect sampling with an emphasis on bean leaf beetles occurred on June 13-14, August 2-3, and September 14, by sweeping across plants 20 times in each plot with a 15-in. diameter sweep net. Insects were placed in Zip-lock bags and transported in coolers to Iowa State University. Insects were frozen until enumeration in the laboratory. Soybeans were harvested on October 31. The percentage of stained soybeans was determined by counting the number of stained soybeans in a 200-gram sample that was randomly collected from the harvest of each plot.