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

Grain sorghum (Sorghum bicolor L. Moench) is comparatively more drought tolerant than many other crops and may help reduce depletion of aquifers used by both agriculture and municipalities.  An experiment at Stoneville, MS in 2012 and 2013 studied 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 per ha (154,274; 181,682; 196,580; and 225,625) but resulted in less grain per head (46.5 g, 40.0 g, 37.2 g, and 33.3 g) and no difference in 1000 kernel weight, thus resulting in no yield differences.  Twin-row plantingsings produced more heads per ha (199,340) than single-row plantings (179,740) but smaller 1000 kernel weights (26.3 g vs.27.4 g) and less grain per head (37.1 g 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 per ha did not increase grain sorghum yields in this experiment.