Author
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Bruns, Herbert |
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Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/24/2014 Publication Date: 1/13/2015 Citation: Bruns, H.A. 2015. Irrigation seedling rates, and row type effects on grain sorghum in the Midsouth. Agronomy Journal. 107:9-12. Interpretive Summary: Grain sorghum, a crop known to require less water to produce a profitable yield may aid in minimizing the depletion of ground water used for irrigation. Only limited information is available on the crop’s production potential in the Midsouth where irrigation has increased greatly over the past 10 years and concerns are growing about its effects on water availability for domestic uses as well as agriculture. A USDA- ARS Scientist with the Crop Production Systems Research Unit at Stoneville, MS, has completed a two year experiment examining the effects of varying seeding rates (40 000, 60 000, 80 000, and 100 000 seed per acre), single- vs. twin-row plantings, and furrow irrigation vs. no irrigation on grain sorghum grown on a clay soil common to the Mississippi Delta. Irrigation did not increase grain yields at any of the seeding rates nor did increasing seeding rates alone increase yields. Twin-row seedings did not yield more grain than conventional single-row plantings. Grain sorghum has a tremendous ability for compensation among the yield components (plants per acre, heads per plant, seed per head, and kernel weight) to stabilize its yield under a wide range of environments. Seeding rates of 40,000 kernels per acre, without irrigation during most seasons appears to produce similar yields to irrigated crops with higher seeding rates, regardless of the row type. This information could help in reducing the depletion rates of ground water resources by growing grain sorghum on some of area’s acreage instead of crops with higher water requirements. Technical Abstract: 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 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 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 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. |
