|Harbach, Chelsea - University Of Illinois|
|Chawla, Shilpi - University Of Illinois|
|Bowen, Charles - Roger|
|Hill, Curtis - University Of Illinois|
|Nafziger, Emerson - University Of Illinois|
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/3/2016
Publication Date: 12/1/2016
Citation: Harbach, C.J., Chawla, S.S., Bowen, C.R., Hill, C.B., Nafziger, E.D., Hartman, G.L. 2016. Association of green stem disorder with agronomic traits in soybean. Agronomy Journal. 108:2263-2268.
Interpretive Summary: Green stem disorder of soybean is the occurrence of non-senescent, fleshy green stems of plants with normal, fully mature pods and seeds. This condition of the plant often makes these plants more difficult for farmers to harvest. The cause or causes of green stem disorder of soybean are not fully understood, but its occurrence has been related to specific soybean cultivars within an environment (location and/or year). This study showed green stem disorder incidence was mostly positively correlated with plant height and lodging, and seed moisture and protein while there was a negative association with seed oil content based on data collected from 86 trials over four years and seven locations in Illinois. There also was an effect of precipitation on green stem disorder, as higher rainfall in the months of May, June, and July were associated with less green stem disorder at the end of the season. These results showed that the degree of GSD incidence was influenced by the soybean cultivar and precipitation levels. This information is useful to soybean geneticists and physiologists interested in delayed maturity and to growers and seed producers.
Technical Abstract: Green stem disorder (GSD) of soybean is the occurrence of non-senescent, fleshy green stems of plants with normal, fully mature pods and seeds. The main focus of this study was to determine the relationship between GSD incidence and agronomic traits and to determine if GSD incidence was associated with soybean cultivars, years, location of trials, and rainfall. Data on GSD incidence based on a percentage of plants in plots showing symptoms were collected for soybean cultivars in 86 trials from 2009 to 2012 at seven locations in Illinois. The incidence of GSD ranged from 0% (three trials) to 88% with a mean incidence of 12% averaged over the 86 trials. GSD incidence was correlated with data on yield, plant height and lodging, and seed moisture, protein, and oil content for all trials. The incidence of GSD was positively correlated (P < 0.05) with yield (12 cases), plant height (24) and lodging (29), and seed moisture (35), protein (19), and oil content (2), and negatively correlated (P < 0.05) with yield (8 cases), plant height (2) and lodging (3), and seed moisture (1), protein (3), and oil content (24). Correlations among agronomic traits, GSD, and in-season precipitation, indicated that yield and precipitation (May, June, and July) were negatively correlated (P < 0.05) with GSD. The incidence of GSD is a result of the genetics of soybean cultivars and how they interact with the environment.