Variety Selection

Most soybean varieties have genetic yield potentials well over 100 bushels per acre. A variety’s adaptability to the environment and production system where it will be used sets the yield potential of the production system. The quality of the weather during the growing season and the stresses from weeds, diseases, and insects determine what the crop yield will be. A variety’s performance in a previously conducted yield trial is a measure of its performance in that particular environment and production system, and does not assure satisfactory performance under a different set of conditions. When a group of varieties is tested for yield over a range of environments, their rank order commonly changes, which indicates that some varieties are better adapted to a specific environment than others. Therefore, it is best to select varieties with characteristics that will help them perform well in the cultural system and environment to be used rather than on their yield record alone. For example, if excessive growth and lodging are problems, then select varieties that are medium to short in height with good standability. If the field has a history of Phytophthora, then select a variety with a resistance gene plus a high partial resistance rating to address that problem. The selection of medium or small seed when using a grain drill will improve metering and stand uniformity. Alternatively, select the varieties that performed best at a test site that is similar to the field for which a variety is being selected, or select a variety that has performed well over several test sites and years that vary widely in yield potential. Maturity information should be used to select varieties that mature at different times to allow for timely harvest. Generally, each 10-day delay of planting in May delays maturity three to four days in the fall. For best yields in wide rows, select full-season varieties with a bushy growth habit. Growth habit is not important in narrow rows. Fitting the variety to the environment is superior to selecting a variety and hoping the environment and weather will fit it.