Irrigation, Seeding Rates, and Row Type Effects on Grain Sorghum in the Midsouth

Grain sorghum [Sorghum bicolor (L.) Moench] is considered more drought tolerant than most other crops and may help reduce depletion of aquifers used by agriculture for irrigation. A study at Stoneville, MS, in 2012 and 2013 examined the effects of seeding rates (98,000, 148,000, 197,600, and 248,000 kernels ha(-1)), row type (single- vs. twin-row) and furrow irrigation vs. no irrigation on yield and yield components of grain sorghum grown on a clay soil. Irrigation did not affect any of the yield components or grain yield in this experiment. Increased seeding rates did increase heads ha(-1) (154,274, 181,682, 196,580, and 225,625) but resulted in less grain per head (46.5, 40.0, 37.2, and 33.3 g) and no difference in 1000 kernel weight, thus resulting in no difference in yields. Twin-row seedings produced more heads per ha (199,340) than single-row plantings (179,740) but smaller 1000 kernel weights (26.3 vs.27.4 g) and less grain per head (37.1 vs. 41.7 g) resulting in no difference in yield between row type. Furrow irrigation, twin-row planting, and seeding rates above 98,000 kernels ha(-1) did not increase grain sorghum yields in this experiment.