Agronomic Maximization of Soybean Yield and Quality: Agronomic Input Effect On Isoflavone Levels.

Since 2008 Michigan State University has been one of six original universities participating in a United Soybean Board project evaluating various soybean agronomic practices and their effect on yield. In this proposal we use same agronomic practices for their effort on soybean quality components. Isoflavones are a group of phytochemicals in some legumes that are thought to contribute to the healthful effects of soybeans in human and animal diets.  Daidzein and genistein are isoflavone aglycones having a 3-phenylchroman skeleton, are mainly found in soybeans (Soja hispida L.) and soy products (Penalvo et al., 2004; Murphy and Barr, 2005) as well as in other species of the Fabaceae family (Liggins et al., 2000); Umphress et al., 2005). The objectives of this project is to determine Isoflavone (mainly Genistein and Daidzen) content of soybean using High performance liquid chromatography as affected by various production inputs used in our United soybean Board project.  Samples are collected from a study that contains 16 different agronomic treatments in the same variety of soybeans, 4 reps each.

Data will be analyzed using Analysis of variance appropriate for a randomized complete-block split-plot design and a randomized complete block design. Mean separations will be accomplished using Fisher’s protected LSD test. Probability levels lower than 0.05 will be categorized as significant. Pearson product-moment correlation coefficients will be calculated based on the data from all plots in each experiment to describe the relationships of daidzein, genistein, and glycitein.

This study will provide valuable information on soybean quality as affected by management inputs. This type of information is currently not widely known and the information will be specifically of value to Michigan growers but also to growers on a national basis and to the public in general. In addition, the quality component analytical results will help determine the efficacy of the different USB treatments, and agronomic practices.