April 24, 2018
We’ve all done the highway drive-by of a soybean field and commented to our passenger how nice and tall the plants look. The question is whether those good-looking soybean plants can translate to a potentially superior yield.
A concern with tall soybean plants is the potential increased risk for lodging. Lodging can occur any time after blooming has begun. Early lodging can cause issues with pod set and fill while encouraging the development of disease. Late lodging raises concerns mainly for harvest, as plants laying over are difficult to get into the header. Soybean lodging can be more common in good production years because of increased height and yield potential.
Generally, more vegetative growth is associated with higher yield potential and if you think about it, this is mostly true. However, with soybean plants, excessive vegetative growth may mean potentially less yield. Soybean plants that use most of their resources for the plant may not have enough energy remaining to push yield potential. In Kansas, it is not uncommon for knee-high soybean plants to out-perform chest-high plants, even though pictures of chest-high soybean plants are more fun to post on social media.
Overall, soybean height should be a consideration. In dryland areas that are prone to stress, a taller product could be a better choice for planting. On knobs in stressed environments, soybean plants can lose their height quickly and become difficult to harvest. The opposite exists for bottom irrigated acres, where tall products may need management to avoid getting too tall later in the season. Growers may stress the plants early on by limiting irrigation or applying a burner herbicide to help restrict plant height. It is important to remember that tall soybean plants with a thick canopy do not always guarantee superior yield.