Brenna Cannon

Planting density can influence the growth and potential yield of grain sorghum systems, particularly in resource-limited environments. Therefore, documenting the sorghum’s response to different planting densities is essential for understanding crop behavior in relation to optimal yields. A study was conducted in Lahoma and Perkins, Oklahoma, in 2019 and 2020 to assess the impact of varying planting densities and within-row planting in-row gaps. Planting density varied from 43,225 to 223,500 plants ha⁻¹. Three additional treatments were implemented at 148,000 plants ha⁻¹ with 0.3, 0.6, and 0.9 m gaps. An increase in plant density resulted in higher yields at Lahoma in 2019. However, at Perkins in 2019 and 2020, yields were optimized at 148,000 and 111,000 plants ha⁻¹, respectively, and decreased as planting densities diminished. In-row gaps of 0.3 and 0.6 m did not significantly affect yields across all site-years; however, at Perkins, the 0.9 m gap significantly reduced yields compared to stands without gaps in both years. Overall, a direct relationship was observed between sorghum yields and planting density. Further evaluation of in-row gaps and how planting management should be adjusted is warranted based on the presented information.

Soybean production in the southern Great Plains (SGP) faces challenges due to yield-limiting factors, including high temperatures and inconsistent precipitation. These conditions can lead to excess vegetative growth, similar to what occurs in crops like cotton. Management strategies utilizing plant growth regulators (PGRs) have been applied to control this excessive growth, yet there is limited information on methods to mitigate vegetative growth in soybeans through modifications to the apical meristem. Field trials conducted in 2022 and 2023 investigated the effects of altering the apical growth using Ascend SL, Compact, Cobra, Cygin Pro, and physical removal, with treatments applied at the V4 and R2 growth stages. This study highlights the significance of customized application strategies to enhance profitability under diverse environmental conditions. Ascend and Cygin Pro demonstrate improving yield stability under adverse climatic conditions. Both applications of Compact produced relatively stable yields across site years, while Cobra and physical removal methods necessitate careful consideration of timing to minimize yield losses. Further research is essential to optimize these management strategies for soybean production in the SGP.