Helping American cotton farmers tackle an invisible threat and grow more from their land
Nematodes and cotton root rot cost American growers an estimated $100 million a year in yield losses, often without visible warning. A new seed treatment from Syngenta is tackling both.
Bowen Flowers comes from a family that has worked American land for almost four centuries. His ancestors arrived in Virginia in 1640, and somewhere in the generations that followed, they made their way to Mississippi, where his family has now farmed for four generations.
Bowen is currently in his 43rd crop season, and farming more than 9,000 acres, of which 3,500 is cotton. Input costs have climbed relentlessly over the last decade, from fertilizers and fuel to crop protection. Growers like Bowen absorb every increase. On the revenue side, cotton prices have not kept pace. And beneath his fields in Mississippi, a problem he cannot see with the naked eye has been quietly cutting into his yields for years.
Left to right: Cotton Graham, Brandon Walton, Andrew Belvedresi, Bowen Flowers
Left to right: Cotton Graham, Brandon Walton, Andrew Belvedresi, Bowen Flowers
"My main problem is reniform nematodes," Bowen says. "They resulted in a yield reduction of 200 pounds last year."
Two hundred pounds per acre, invisible from above, gone before the season ended.
The problem under the surface
Nematodes are among the most damaging pests in American cotton farming, and the least understood.
"Every cotton farmer has nematodes in their fields. Most of them don’t know it,” says Shannon Morsello, Seedcare Technical Product Lead at Syngenta. “Typically, farmers only identify the problem after noticing a yield impact and working backward through a process of elimination.”
Microscopic view of a soil nematode.
Microscopic view of a soil nematode.
Cotton is produced across a wide southern belt, from Texas and Arizona in the southwest to Georgia, Mississippi, and the Carolinas in the southeast. Different nematode species tend to dominate different soil types. Rootknot nematode, which develops as spindle-shaped galls on plant roots, is the single biggest pathogen for cotton in the US. But reniform nematode, the type that has been hitting Bowen’s Mississippi fields, is what Shannon calls a silent killer.
"Reniform nematodes are deceptive," she says. "Below ground, infested roots often look dirty because soil sticks to the females and egg masses on the roots. Above ground, however, the cotton can look healthy, making it easy to miss the problem until lower yields reveal it at harvest." Collectively, the industry loses around $100 million a year to nematode damage.
In the southwest, a different pathogen adds to the toll. Cotton root rot is a soil-borne fungal disease that has afflicted growers in Texas and Arizona since the late 19th century. Unlike nematodes, it can be seen in the field, but by the time it is visible, the damage is often already severe. Mark Nemec, a consultant who has worked with cotton growers in Texas since 1995, describes what it looks like when an outbreak takes hold.
"Reniform nematodes are deceptive," she says. "Below ground, infested roots often look dirty because soil sticks to the females and egg masses on the roots. Above ground, however, the cotton can look healthy, making it easy to miss the problem until lower yields reveal it at harvest." Collectively, the industry loses around $100 million a year to nematode damage.
Map showing spread of reniform nematode in the USA.
Map showing spread of reniform nematode in the USA.
In the southwest, a different pathogen adds to the toll. Cotton root rot is a soil-borne fungal disease that has afflicted growers in Texas and Arizona since the late 19th century. Unlike nematodes, it can be seen in the field, but by the time it is visible, the damage is often already severe. Mark Nemec, a consultant who has worked with cotton growers in Texas since 1995, describes what it looks like when an outbreak takes hold.
Map showing the spread of southern root knot nematode in the USA.
Map showing the spread of southern root knot nematode in the USA.
"The crop appears shrunken and then dies within days," he says. "It works its way up from the root. I know growers who lost 20 acres out of 100 to it."
The fungus persists in the soil indefinitely, lying dormant through crop rotations and reviving when cotton returns. In fields with repeated cotton planting over three or four seasons, cotton root rot can ruin smaller plots outright and wipe out 25 to 30 percent of larger ones. It thrives in the heavy alkaline and calcareous clay soils of central Texas, at temperatures between 95 to 102 degrees Fahrenheit.
Until recently, existing solutions required spray applications. The problem was that excessive application damaged cotton germination, hurting the very yield growers were trying to protect.
A different approach
Now, Victrato, Syngenta's broad-spectrum seed treatment, takes a different approach. The active ingredient is applied directly to the seed before planting, which changes both the mechanics and the risk profile of protection.
Bryn Hightower, Product Lead for Seedcare at Syngenta, explains the significance. “Earlier nematode treatments were limited to closed application systems, restricting access for many growers. Victrato removes that constraint.”
Shannon describes the mode of action: "Victrato interferes with biological processes essential for nematode development and reproduction. As a seed treatment, it helps protect young cotton plants during the critical early stages of growth, when nematodes can readily penetrate developing root systems. By targeting nematodes where they first interact with the crop, Victrato helps reduce the impact of feeding and reproduction that can lead to yield loss.”
"The challenge is making the invisible visible," Shannon says. "Nematodes penetrate root systems when plants are young and growing. The seed treatment meets them there."
The product is also effective against cotton root rot, working to suppress the fungal pathogen in the soil around the treated seed. Across 28 trials conducted over five years, Victrato outperformed traditional in-furrow applications by an average of 239 pounds per acre. In Mark's experience, what he observed in the field backed that up.
"What we saw with Victrato is that it managed to stop cotton root rot from spreading by suppressing it," he says. "We saw this over 40 acres of land."
Cotton root rot's impact on untreated field 95 days after planting.
Cotton root rot's impact on untreated field 95 days after planting.
Cotton crop protected by Victrato 95 days after planting.
Cotton crop protected by Victrato 95 days after planting.
A season to watch
Some relief may be on the way for growers this season. The rise in oil prices has made polyester, an oil-derived synthetic fiber, more expensive, pushing some buyers back toward cotton. After a difficult season, in which record yields paradoxically drove prices down through oversupply, growers across the cotton belt are watching the market recover.
"The grower today is selling at 80 cents per pound of cotton," says Mark, drawing on three decades of work alongside Texas growers. "That is the same price as 1995. In that time, input costs have risen more than three times over."
This year, Bowen’s acres of cotton will be treated for the first time with Victrato to manage reiniform pressure on the crop. “Victrato is the easiest to use for growers because it can be used as a seed treatment and not sprayed,” Bowen says.
It is a small operational shift with a larger hope behind it.
"I am hoping for a good harvest," he says, "and a good return on my investment."
