Evaluating plant density in grain sorghum using GreenSeeker

Abstract

Grain Sorghum (Sorghum bicolor(L)Moench,) is a high yielding, drought tolerant crop commonly grown in Oklahoma and the southern Great Plains. Increased knowledge of agronomic production practices, such as planting densities, will be required to continue to increase yields in these environments. Two different trials were used to evaluate planting density. This first evaluated planting densities effects on sorghum yield and the second evaluating the potential of using remote sensing techniques to quickly evaluate sorghum plant densities. A non-significant relationship was found between NDVI and planting densities. Better relationships were found with CV of NDVI and planting densities, especially at 4 WAP (P <.01; r2= 0.61). Grain sorghum yields were significantly impacted by planting densities. Significant yield decline was found when planting densities were decreased from 75,100 to 111,150, depending on the year, with a 30%, 55% and 12% reduction in yield for Lahoma 2019, Perkins 2019, and Perkins 2020 respectively. If producers were to consider replanting, a critical CV of NDVI value of 9.4 to 11.9% should be considered. This work shows that a model could be further developed for replanting and other management decisions.