HARLINGEN — Lowly grain sorghum isn’t the sexiest agricultural commodity grown in the Rio Grande Valley, even though the crop’s orangy-red seed heads are a bright summer sight along the roadways.
Cameron, Willacy and Hidalgo counties year in and year out rank among the top state producers of sorghum. And when it comes to acreage in these counties, sorghum has a far bigger footprint than cotton, corn, citrus or sugar cane.
Since 2014, the Valley’s annual crop of between 300,000 and 350,000 acres of sorghum, primarily used for livestock and poultry feed, has been beset by a pest known as the sugarcane aphid.
Why the insect switched its affections from sugar cane to sorghum isn’t really understood.
But today, the tiny bug is public enemy No. 1 when it comes to Valley agriculture.
“It’s something we haven’t had to deal with up until about three years ago,” said Lyford farmer Glenn Wilde, who sits on the board of the Texas Grain Sorghum Producers Association.
“It can cost us up to $15 or $30 more an acre, when sorghum isn’t that lucrative of a crop to begin with,” he said yesterday. “It really cuts into your gravy.”
Danielle Sekula-Ortiz, a pest management specialist with TAMU AgriLife Extension Service in Weslaco, said there’s still a debate among entomologists about where this particular subspecies of sugarcane aphid originated. Its arrival nevertheless was a shock to Valley sorghum growers.
“These guys didn’t know what they were, they thought we were crazy or whatever,” she said of AgriLife entomologists who study the aphids. “I said, ‘You don’t believe in getting your consultant to come out there and look at it?’
“Then overnight we started getting all these phone calls from growers saying, ‘What do we do? What do we spray?’” she recalls. “Crazy.”
The losses to grain sorghum growers in the Valley to the sugarcane aphid are significant — an estimated $21.87 million in 2014, and $17.13 million in 2015. Numbers for 2016 aren’t yet available.
“In the Valley, sorghum is the top commodity produced in value and the number of acres planted,” said Samuel Zapata, an agricultural economist with AgriLife in Weslaco.
“Basically this aphid has two main facts,” Zapata said. “Reducing revenues because the growers are producing less than they’re supposed to produce, and they are selling less.
“Also impacting profit is that with the sugarcane aphid growers are facing a higher cost of production,” he said. “Why? Because they are using more insecticide to control the pest, and also you need to pay somebody to do the spraying. Even if you do it yourself, there is a cost.”
Much of this year’s grain sorghum crop is already in the ground. Given the warm weather, growers were anxious to plant early to avoid having to apply expensive pesticide twice during the season to kill off a second hatch of aphids that comes later in the year.
“If farmers don’t spray at least once during the growing season, they have a chance to lose 50 percent of their crop,” Sekula-Ortiz said. “It’s amazing what they can do,” she says of the bugs.
Valley sorghum growers today are pretty savvy about the risks, she said.
“Ninety percent of our growers know what’s up, they know how to scout” for early aphid sign, she said. “My guys down here are pretty well-trained.”
The sugarcane aphid doesn’t just damage grain and reduce yields, it also has an additional aggravation for farmers — a sticky, sweet honeydew substance it secretes on plant leaves.
It is thought this is a defense against predators, but the honeydew gums up harvesting equipment and costs a grower time and money when bringing in a crop. That generally happens in early June in the Valley.
“When you see the seed and it’s already orange, the seed is already hard, it’s already matured and drying down and getting ready for those guys to go in and harvest it,” Sekula-Ortiz said. “But right before that, it’s green and soft, and if (aphids) can populate the leaf, they’ll crawl up to the sorghum head and that’s your cash, that’s your money there.
“They make it into a really sticky mess,” she said. “That’s how these guys will lose 50 if not 100 percent of their crop if they don’t spray.”
There is good news for growers when it comes to spraying. The Environmental Protection Agency just approved a renewal of a Section 18 exemption which had lapsed allowing the use of a pesticide called sulfoxaflor, sold by Dow Chemical Co. under the brand name Transform, against sugarcane aphids.
Bayer CropScience’s Sivanto pesticide became available for use against sugarcane aphids in 2015.
“At least that’s a positive anyway, that we have something at least to fight it,” Wilde said of the EPA decisions. “Other countries are able to use products that we can’t use anymore, and that puts us at a disadvantage.”
Other countries also are an important market for grain sorghum produced in the United States, with Mexico and China two of the biggest markets for the crop. China imports 80 percent of the U.S. grain sorghum crop.
“China really likes sorghum,” Wilde said. “It makes the gizzard on a duck bigger.”
And the breast meat of chicken is whiter when poultry is fed sorghum. Corn tends to create a less attractive yellow coloration in the chicken breast, he said.
“They like it, but if we can’t be a dependable supplier, they have no choice but to go with corn or go somewhere else” for grain sorghum, he said of the Chinese.
Grain sorghum producers elsewhere in Texas are definitely going somewhere else — planting other crops.
Sugarcane aphids thrive in dry areas, and that puts the Valley at somewhat of an advantage over regions where the humidity is usually lower.
“Up in the Lubbock area, where it’s a little bit drier, they have to spray two or three times” a season, Wilde said. “They’re pretty much quitting it up in the Lubbock area, and either going with corn or all cotton.”
For AgriLife’s Sekula-Ortiz, the sugarcane aphid outbreak provided a test of the Texas agricultural industry’s rapid-response ability, one she feels the TAMU AgriLife Extension Service passed.
“We saved grain sorghum growers in 2014 with our efforts,” she said. “We are very proud of that.”
