Can sorghum establishment be improved under sub-optimal soil temperatures? Gurley 2021–2022

Abstract

Key findings •Establishing sorghum into soils cooler than the commercially recommended 16–18 °C is a viable option to move flowering and grain fill periods earlier. Planting earlier can help avoid heat and moisture stress at flowering and grain fill. •Targeting soil temperatures greater than 12 °C for 7 days after planting, and planting into good seedbed moisture, can help even plant establishment, which is important when choosing to plant early. •Under sub-optimal soil temperatures, establishment is often less than desired (approximately 80%). Three factors were tested to see if establishment percentages could be improved including: ºvarying planting depth ºusing better quality seed ºusing different seed treatments to promote quicker seed germination and emergence •Seed treatment did not affect plant establishment compared with the untreated control. •Seed quality did affect establishment. The good quality MR Bazley seed established around 10% more plants than the poor quality seed lot, regardless of planting depth or seed treatment. •There were no differences in tiller or head production, grain yield or grain quality across any of the treatments.