Sorghum Plant Height’s Contribution to Yield
Sorghum Plant Height’s Contribution to Yield
Brent Bean, Sorghum Checkoff Director of Agronomy
A recent Texas A&M article publication in the prestigious Journal of Crop Science, examined the impact of plant height on yield and lodging by analyzing the results of 50 years of Texas variety trials. Growers are often reluctant to plant tall sorghum hybrids because of the perception that this will lead to lodging. In reality, plant height only plays a minor role in determining if a sorghum plant will lodge. While common sense does tell us that increased plant height must increase the risk of lodging, the results of the analysis of this extensive dataset strongly suggests that the risk is minimal. The graph below clearly shows no correlation between plant height and lodging.
For a discussion on lodging see Causes and Prevention of Sorghum Lodging on the USCP Agronomy Insights Page.
The analysis revealed a clear and positive correlation between sorghum plant height and yield. This positive association has been well documented in other studies. Although the exact cause of this association is unknown, the hypothesis is that taller plants have longer internodes resulting in a greater distance between leaves. This distance allows for better light capture resulting in improved photosynthesis that results in improved yield.
In the Texas A&M study, the average height of the sorghum varieties tested was 48 inches. By simply increasing the plant height six inches, yield was increased 900 lbs, or 16 bushels! It is important, however, that the selected taller hybrid stays within the desired maturity for your environment.
The conclusion of this study was that sorghum height plays a significant role in yield. By accepting a slightly taller plant, yield can be increased without the risk of increased lodging.