South Texas Nearing Harvest, Growers Encouraged to Scout for Aphids


by Shelee Padgett
Sorghum Checkoff Field Services

While on a recent crops tour in the Coastal Bend of Texas, I saw first-hand the good condition of the grain sorghum crop thanks to the 1 to 9 inches of rainfall that fell across the region. Much of the sorghum in the Coastal Bend is already heading and some is starting to turn color. Likewise in the Rio Grande Valley, sorghum is progressing well and harvest is not far off as grain sorghum is already turning colors.

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By June 1, U.S. growers had planted 56 percent of this year’s sorghum crop, 5 percentage points ahead of last year but slightly behind the five-year average. Advances of more than 20 percentage points were seen in Illinois, Nebraska and South Dakota. Crop conditions in Texas were 10 percent good, 37 percent excellent, and 42 percent fair.

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While no major quality issues have been identified as of yet, one key issue growers need to be aware of in South Texas is the sugarcane aphid, which has moved into the area. This insect is typically known as a key pest to sorghum and sugarcane in tropical and subtropical regions around the world, and did create minor production challenges for grain sorghum growers in South Texas, southern Oklahoma and part of Louisiana and Mississippi in 2013 without significantly impacting U.S. sorghum production.

Recent reports from the field indicate the aphid is continuing to move north and east from the Coastal Bend and can move rapidly through the field if not monitored. For example, in Nueces County, the bug was first observed in numerous fields in low populations on and around May 16. Then on May 20, an area producer reported heavy infestations in a field. The sample brought into the Nueces County extension office had several hundreds of aphids on the underside of the leaf and was representative of about 20 percent of the plants in the field.

For this reason, growers are highly encouraged to take a proactive approach and carefully monitor their grain sorghum fields early and often for this invasive pest. Aphids can impact sorghum at all growth stages. Proper scouting and spraying can help minimize the impact of the sugarcane aphid to sorghum.

What should producers be scouting for?

The aphid does not appear to vector any type of plant disease, and producers will not need to treat at the first sign of this pest. The aphid does feed on the leaves causing discoloration, while also producing large amounts of honeydew, a sticky secretion that causes mechanical problems in combine at harvest.

A Section 18 for Transform WG by Dow AgroSciences has been approved in Texas, Louisiana and Oklahoma to help producers control the sugarcane aphid in grain sorghum. For spraying guidelines, please consult the label for your respective state.

Dr. Mike Brewer, Texas AgriLife Research entomologist, has outlined several suggestions to maximize scouting efforts for this pest. Read his suggestions here.

In the meantime, a task force comprised of the Sorghum Checkoff, Texas Grain Sorghum Producers, Texas AgriLife Research, Oklahoma State Extension, LSU AgCenter and USDA-ARS is working to develop resistant grain sorghum hybrids as well as other agronomic practices to reduce insect pressure.