Grain Sorghum Yield Components as Influenced by Hybrid, Seeding Date, and Irrigation

Core Ideas Grain sorghum, though not a new crop to the Lower Mississippi River Valley, has received very limited attention in recent years with respect to management research. Row‐crop irrigation has greatly increased in the Mississippi Delta over the past 20 years to where sub‐surface acquifers are being mined at unsustainable rates. Grain sorghum appears to benefit very little or not at all from irrigation and may provide a cash crop that will help reduce irrigation water depletion. Production practices of grain sorghum that manage around some of the newer pest problems that have recently appeared are in need of development.Grain sorghum [ Sorghum bicolor (L.) Moench] production retains some interest in the midsouth states as a rotation crop and a drought‐tolerant option in limited or non‐irrigated cropping systems, thus helping conserve water resources. An experiment was conducted using four grain sorghum hybrids to measure the effects of irrigation vs. no irrigation plus May vs. June seeding dates on yield and yield components of the crop. The May seeding was the normal time of planting while the June seeding simulated double‐cropping after wheat ( Triticum asetivum L.) Furrow irrigation had no impact on seed yield at either seeding date. June seedings were lower (≤4626.4 kg ha −1 ) than May seedings (≥5168.3 kg ha −1 ). No differences among hybrids were observed between years of the two May seedings. However, all hybrid yields for June seedings in 2017 were significantly less than the 2016 crop. Heads per hectare basically did not differ between years, but May seedings produced more heads (≥134,167 heads ha −1 ) than June seedings (≤118,504 heads ha −1 ). Despite reduced grain yields by June seedings, the lack of having to irrigate double‐crop grain sorghum as opposed to having to irrigate double‐crop soybean [ Glycine max (L.) Merr.] makes the former a viable option for water conservation and potential profit.