Evaluation of Soybean Varieties for Certified Organic Production⎯Neely-Kinyon Trial, 2005

Materials and Methods Varieties selected for the 2005 organic soybean variety trial included the following: IA3017, NC+2FN93, NC+3F43, Schillinger XP304, Schillinger 240F.Y, MRK0431CTB, and Pioneer 9305. Plots measuring 20 × 100 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 27, 2005, at a rate of 205,000 seeds/acre. Weed control was established through the following procedures: rotary hoeing on June 15 and June 22; cultivation on June 17 and July 1; and walking plots on August 2. Plant stands were counted on June 17 and June 20. Insect sampling with an emphasis on bean leaf beetles occurred on June 17 and July 13, by sweeping across plants 20 times in each plot with a 15-in. diameter sweep net. Insects were placed in Ziplock bags and transported in coolers to Iowa State University. Insects were frozen until enumeration in the laboratory. Soybeans were harvested on October 11. 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.