By Angela McClure, Extension Corn and Soybean Specialist
I have had a number of calls about grain sorghum this week as lower production costs compared to corn and the latest increased premium offered for Memphis delivery have driven up interest in this crop. Check out our newest regional sorghum production guide at utcrops.com. Some pre-plant reminders are included about sorghum for those who have not grown sorghum lately (or ever):
- Do not use Leadoff in burndown where you plan to plant sorghum. Sorghum is very sensitive to the rimsulfuron component of Leadoff and also high doses of fomesafen from Reflex/Prefix/Flexstar carryover. Also, consider applying any atrazine POST to reduce possibility of injury from pre-plant atrazine.
- Plant varieties with a good yield record. Table 1 is a 2 year summary of irrigated and dryland variety results from Arkansas courtesy of their sorghum specialist, Dr. Jason Kelley. Keiser is a clay soil and Marianna is a silt loam soil. Check seed company ratings for stalk rot resistance where Anthracnose and Fusarium have been problems in past years.
- Uniform emergence is key. Plant into moist, warm soils 1” deep and close planter slot well. We can plant sorghum as early as mid- April in 60 degree plus ground but delay planting if soils are cool and weather is not favorable for rapid emergence. Uniform emergence means heading/bloom/maturity are uniform and the crop is MUCH easier to manage for insects and desiccation.
- Don’t overplant. A final stand of 60,000 to 70,000 plants per acre is adequate for good yields regardless of row spacing. Table 2 lists seeds/ft of row for desired stands. Assume about 85% of seed will germinate and increase seed drop amount slightly if planting into less than optimal emergence conditions. (Example: drop 90K in cool no-till soils where 70K is desired).
- Apply all N by V6 stage sorghum. Earlier is best. UT recommends 60 to 90 lbs N/acre for dryland sorghum. Producers who irrigate have used up to 120 lbs N on high yielding ground. Most producers apply a small amount at planting and follow with a urea topdress or UAN behind a coulter. Do not topdress with ammonium nitrate as leaf burn is much greater compared to urea. Add Agrotain stabilizer to surface-applied urea if rain is not likely.
| Table 1. Two Year Average Yields of Grain Sorghum Hybrids in The Arkansas Performance Trials, 2013-2014 |
| | Keiser Irrigated | KeiserNonIrrig. | MariannaIrrigated | IrrigatedAverage |
| Brand/Hybrid | —————————–bu/acre———————– |
| BH 3822 | 138.0 | 139.1 | 143.9 | 141.0 |
| DEKALB DKS51-01 | 145.5 | 126.6 | 155.2 | 150.4 |
| Dyna-Gro 765B | 133.8 | 124.6 | 143.8 | 139.0 |
| Dyna-Gro M75GB39 | 120.7 | 127.4 | 132.9 | 126.8 |
| Dyna-Gro M77GB52 | 116.3 | 119.6 | 143.0 | 129.7 |
| Dyna-Gro M77GR61 | 122.0 | 106.9 | 137.9 | 130.0 |
| Pioneer 83P99 | 139.0 | 127.0 | 146.7 | 142.9 |
| Pioneer 84P80 | 136.1 | 134.0 | 154.8 | 145.9 |
| REV® RV 9562™ | 124.4 | 125.9 | 142.2 | 133.3 |
| REV® RV 9782™ | 129.4 | 126.3 | 134.9 | 132.2 |
| REV® RV 9883™ | 125.9 | 127.9 | 141.6 | 133.8 |
| REV® RV 9924™ | 129.6 | 130.5 | 141.1 | 135.4 |
| Trial Mean | 130.1 | 126.3 | 143.2 | 136.7 |
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