Systematic Optimization of Soybean Yield and Quality: Management Interactions on Isoflavones.

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 that  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 objective of this project is to determine isoflavone (mainly genistein and daidzein) content of soybean using High Performance Liquid Chromatography (HPLC) as affected by various production inputs used in a 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. Treatments include individual and combinations of seed treatments, inoculant, foliar fungicide, foliar insecticide, lipo-chitooligosaccharide (LCO), a defoliant, an antioxidant, foliar fertilizer, and nitrogen fertilizer.

To describe the relationships of daidzein and genistein, 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. Results from 2012 and 2103 study have shown that there are significant differences in the isoflavone content in between the treatments and locations with environment playing a substantial role.

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.