Field study shows unique corn trait is effective in limiting impact of corn rootworm

Syngenta Seeds announced results from a recent field study on the effects of corn rootworm (CRW), highlighting that hybrids with the Agrisure Duracade trait have proven effective in limiting the impact of CRW. Growers in the Midwest are seeing heavy CRW pressure this year, a likely result of large beetle populations in past seasons, good overwintering of CRW eggs and favorable spring conditions for larval survival.

CRW has a highly-adaptative life cycle, and populations can build year after year in fields when left uncontrolled, costing growers around $1 billion in lost yield and control measures each year. It is critical to utilize long-term management strategies to get ahead of pressure and manage this pest year over year.

In addition to using sticky traps to monitor adult CRW populations, one strategy to monitor CRW pressure and analyze the performance of management options is a root dig, which is performed to inspect the integrity of field corn's root systems.

"When the larvae feed on the roots, it can reduce water and nutrient uptake. In extreme cases, root lodging occurs where the roots become so damaged that they cannot properly anchor the plant to ground, making them susceptible to strong winds," said Bruce Battles, technical agronomy manager for Syngenta. "Root digs are valuable because they assess that threat, so we can make the proper adjustments to future CRW management programs."

In July, the Syngenta Seeds agronomy team conducted a series of root digs across Nebraska, Iowa and Illinois to inspect traited hybrids that were planted in the spring. Roots from seven trial locations were washed and scored with the data compiled at the Syngenta Seeds research facility in Slater, Iowa. The goal of the digs was to see how hybrids with the Agrisure Duracade trait compared to non-treated and other rootworm-traited hybrids.

Key results from these root digs include:

• Using the 0 to 3 Node-Injury Scale from Iowa State University, the average root injury score of the untreated check was 1.5 nodes damaged (higher root scores indicate more corn rootworm damage).

• Using that same scale, the Agrisure Duracade-traited plants had 0.35 node damaged.

• Qrome^®, SmartStax^® and Agrisure Duracade trait stacks rated similarly across locations.

"The dig's results confirm what growers have been seeing in their fields: hybrids with the Agrisure Duracade trait demonstrate more effective control of CRW to protect field health and yield potential than those left untreated," said Battles. "We're thrilled with these results, because it means growers are well-equipped in their defense against CRW, and we are looking forward to seeing more success this season and in the coming years."

The Agrisure Duracade trait is a unique rotational option with novel, alternate modes of action to preserve trait durability, long-term field health and yield potential.

Check (left), Agrisure Duracade (middle left), Qrome (middle right), SmartStax (right)

Effective, long-term CRW management requires a multi-year, whole-farm approach that includes the integration of multiple control measures, not a singular technology. Growers with heavy CRW pressure should consider incorporating the following control measures into their CRW management approach:

• Rotate to a non-host crop such as soybeans, which provides the best opportunity to break the reproductive cycle of CRW.

• Plant hybrids with multiple CRW traits, including Agrisure Duracade trait stacks and Agrisure^® 3122 E-Z Refuge.

• Scout and evaluate the need for adult beetle control with a foliar insecticide like Warrior II with Zeon Technology^®

• If past history indicates high CRW pressure may occur, consider the use of a multiple CRW-traited hybrid and a soil-applied insecticide like Force^® 6.5G

"Although there is not one guaranteed solution, there are tactics that can be used in a multi-year CRW management plan like crop rotation, soil-applied insecticides, adult beetle control and traited hybrids that farmers can use to get ahead of corn rootworm pressure," said Tim O'Brien, PhD, Agrisure^® traits manager for Syngenta. "The results of this dig suggest growers should strongly consider adding hybrids with the Agrisure Duracade trait to their whole-farm corn rootworm management approach to show corn rootworm something differentand delay insect adaptation."

For more information on Agrisure Duracade trait stacks and to find additional resources about proactive CRW management, visit www.agrisureduracade.com. A step-by-step Take Control of Corn Rootworm Management Brochure may also be accessed here. Join the conversation online - connect with Syngenta at Syngenta-us.com/social.