Greater values are possible in special situations.
Both genetics and environment are important factors in determining levels of value-added properties such as protein, oil, starch or hardness. Since 1986 Iowa State University has published composition data in its Corn and Soybean Yield Tests. However, the plots in these tests contain many more varieties than would be commonly grown or emphasized by seed companies for genetic potential. Plots are weighed at harvest, and, in this program, are sampled for several quality factors. These plots provide an excellent opportunity to relate quality and yield data in a localized setting.