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Posted 29 August 2006. PMN Crop News.

New Data Confirms Herculex RW, Herculex XTRA Protect Corn Roots Better Than Other Technologies

2006 Root Digs Show Consistent, Persistent Performance

Pioneer Hi-Bred International, Inc.


Des Moines, Iowa (August 9, 2006) – Research conducted across the Corn Belt in 2006 by Pioneer Hi-Bred International, Inc., shows that corn hybrids with the Herculex® RW Rootworm Protection and Herculex® XTRA traits provide excellent protection against corn rootworm that is superior or equivalent to other management techniques available to growers, including other biotech options.

A multimedia news release is available online.

"Based on the thousands of roots we evaluated, it's clear that those with Herculex RW or Herculex XTRA provide industry leading protection against corn rootworm damage, a problem that more and more growers are facing," said Murt McLeod, research scientist with Pioneer Agronomy Sciences.

Root digs were conducted among 15 different sites throughout the Corn Belt, evaluating a broad range of corn rootworm management technologies, such as in-plant biotech traits, insecticide seed treatments and traditional granular insecticides. All were compared to unprotected checks.

The studies were conducted by Agronomy Sciences professionals from Pioneer and are part of the continuing evaluation by Pioneer of its products. Additional root digs are being done by land grant university entomologists this season and will be released later.

Among six sites experiencing high corn rootworm pressure, Pioneer® brand corn hybrids with the Herculex RW and Herculex XTRA traits provided excellent protection. Root damage ratings on Pioneer hybrids with the Herculex RW and Herculex XTRA traits were equal to or better than DeKalb® hybrids with YieldGard® Rootworm Protection and YieldGard® Plus traits. The results showed that, on average across the six locations, roots with the Herculex RW and Herculex XTRA rootworm technology averaged 0.10 root nodes damaged and, within the same six sites, roots with YieldGard rootworm technologies had 0.21 root nodes damaged. At one northwest Iowa location, Herculex technologies showed minor root scarring (rating = 0.06) while YieldGard technologies averaged over half of a root node destroyed (rating = 0.6).

Evaluations are based on a 0-3 root node scale with 0 being no damage and 3 a fully damaged root.

In addition, consistency ratings, an indicator of variability of root protection, were noticeably higher for Herculex RW and Herculex XTRA rootworm technologies compared to YieldGard rootworm technologies. The corn rootworm protection systems were rated for consistency of protection with damage equal to or less than 0.25 nodes. Across high pressure locations, on average 97 percent of the Herculex RW and Herculex XTRA rootworm roots met the consistency criteria, while only 80 percent of the plants containing YieldGard rootworm technologies met the consistency criteria. Aztec® insecticide also showed a consistency of 80 percent.

The studies also showed that hybrids with the Herculex RW and Herculex XTRA traits provided excellent standibility in environments where untreated checks had significant early root lodging.

The Herculex RW trait provides season-long protection for corn roots against western, northern and Mexican corn rootworm and is the only transgenic rootworm technology that consistently reduces the emergence of adult rootworm numbers by an average of 92 percent.

Herculex XTRA protection is a combination of Herculex RW and Herculex I traits for the broadest in-plant insect protection in the industry. In addition to defending the plant by controlling corn rootworm, Herculex XTRA helps protect against European and southwestern corn borer, western bean cutworm, black cutworm and fall armyworm.

A second round of root evaluations will take place later in the season to confirm the season-long protection from Herculex RW and Herculex XTRA technologies. Harvest and yield data will also be collected in the fall.


Jerry Harrington
800-247-6803, ext. 6908