This item is adapted from an AgriLife submission to Texas Grain Sorghum Association’s “Sorghum Insider”
Calvin Trostle, Ph.D., Professor & Extension Agronomist, TAMU Dept. of Soil & Crop Sciences, Lubbock, (806) 746-6101, ctrostle@ag.tamu.edu
Texas A&M AgriLife Extension thanks Dr. Brent Bean (brentb@sorghumcheckoff.com), national agronomist, United Sorghum Checkoff Program (USCP) for information in this Sorghum Tip. Dr. Bean presented this and other information, especially updates on grain sorghum herbicides, to the High Plains Association of Crop Consultants meeting in Lubbock, March 1, 2023.
Sugarcane Aphid Mystery Resolved
Since “sugarcane aphid” appeared on grain sorghum (late 2013) there has long been a question if this was a new biotype of the of the sugarcane aphid (Melanaphis sacchari). After DNA sequencing entomologists have now concluded the aphid infesting sorghum is actually a biotype of the species Melanaphis sorghi or “sorghum aphid.” Going forward when growers hear entomologists and others referring to the sorghum aphid this is nothing new but simply the same aphid that has been referred to as the sugarcane aphid for the last few years.
Recognizing this new understanding, Blayne Reed, IPM Extension agent, Hale & Lamb Counties, Texas, notes this current aphid will now be more correctly known as the ‘sorghum aphid’. This does not change AgriLife Extension’s understanding of the insect, its management, or Extension’s treatment suggestions in any way.
New Promising Herbicide Treatments for Pigweed/Palmer Amaranth in Grain Sorghum
As too many Texas sorghum growers know, pigweed/carelessweed/Palmer Amaranth is a huge concern in Texas grain sorghum. Furthermore, the further erosion of common atrazine use due to tightening use restrictions may requires alternate chemistries to fulfill the role atrazine has played in sorghum production for decades.
USCP continues to fund research examining herbicide options that do not involve atrazine. Two treatments that stood out in 2022 trials were Verdict + Outlook and Coyote, which is a combination of mesotrione + s-metolachlor. In addition to these treatments, herbicides labeled in other crops were examined, with several showing good pigweed control with minimal or no crop injury. It is hoped that in the future companies may consider modifying their labels to include sorghum.
Comparisons of New Grass Herbicide-Tolerant Sorghum Hybrid Families
More grass-herbicide tolerant grain sorghum hybrids will be on the market for 2023. These allow for grass control in grain sorghum, which is itself a grass.
| Sorghum New Herbicide Tolerant Technologies | |||
| igrowth® | Inzen™ | Double Team™ | |
| Seed Company/ Herbicide Company | Advanta/UPL | Pioneer/Corteva | S&W/ADAMA |
| Herbicide | ImiFlex™ | Zest™ | FirstAct™ |
| Mode-of-Action | ALS (imi subclass) | ALS ( SU subclass) | ACCase ( Fop subclass) |
| PRE Use | Yes | No | No |
| POST Use | Yes | Yes | Yes |
| Broadleaf Activity | Moderate | A little | None |
| Crop Rotation Concerns | Check label for wheat restrictions | Minimal | Minimal |
| Seed per Bag | 600,000 | 50 lbs | 600,000 |
| Summary courtesy Dr. Brent Bean, United Sorghum Checkoff Program, March 2, 2023 | |||
Remember, each of these grain sorghum hybrids must be paired only with the designated specific herbicide for each technology. Always follow label directions.
A PowerPoint with expanded information on these three herbicide technologies is posted at http://lubbock.tamu.edu/sorghum
For additional information on herbicide options for grain sorghum contact your regional AgriLife weed scientist, United Sorghum Checkoff Program, or your chemical dealer.