Fall 2018 was extremely wet, and as a result, small grain and cover crops throughout the state were planted late. Some farmers are interested in planting soybeans with an earlier relative maturity to facilitate timely harvest and establish a small grain or cover crop. But, what is the yield trade-off? In 2017 and 2018, we conducted trials in Wood County and Clark County, Ohio to examine the effect of soybean relative maturity on grain yield.
In Wood County, we tested sixteen soybean cultivars ranging in maturity from 0.3 to 3.8 (Figure 1). Soybean yield increased with increasing relative maturity until 2.9. At a relative maturity of 2.9, soybean yield plateaued. Although, soybean grain yield was the same for the 2.9 through 3.8 cultivar, the cultivar with the 2.9 relative maturity reached physiological maturity (R8 growth stage; 95% pods mature color) approximately seven days earlier.
Figure 1. Effect of soybean relative maturity on grain yield in Wood County, Ohio, 2017-2018.
In Clark County, we tested sixteen soybean cultivars ranging in maturity from 1.1 to 4.6 (Figure 2). Soybean yield increased with increasing relative maturity until 3.2 (Figure 2). At a relative maturity of 3.2, soybean yield plateaued. Although, soybean grain yield was the same for the 3.2 through 4.6 cultivar, the cultivar with the 3.2 relative maturity reached physiological maturity approximately fifteen days earlier.
Figure 2. Effect of soybean relative maturity on grain yield in Clark County, Ohio, 2017-2018.
The Ohio Agronomy Guide states, “Relative maturity has little effect on yield for plantings made during the first three weeks of May…” Data from our research trials support this statement.