HERCULEX® XTRA FAQ

HERCULEX^® XTRA FAQ

If you don't find answers to your specific questions on HERCULEX^® XTRA Insect Protection here, feel free to ask our experts.

What is HERCULEX^® XTRA Insect Protection?

HERCULEX^® XTRA Insect Protection is an in-plant, insect protection trait discovered by Dow AgroSciences and developed in a research collaboration between Dow AgroSciences; its retail seed company, Mycogen Seeds; and Pioneer Hi-Bred International Inc.

HERCULEX XTRA is a stacked trait that combines the broad-spectrum, above-ground protection of HERCULEX I Insect Protection with the powerful below-ground protection of HERCULEX RW Rootworm Protection. HERCULEX RW Rootworm Protection offers protection against larval stages of major corn rootworm pests, including western, northern and Mexican corn rootworm.

The genetic trait utilizes the Cry1F, Cry34Ab1 and Cry35Ab1 genes. These genes express an insecticidal protein derived from a naturally occurring soil micro-organism, Bacillus thuringiensis (Bt).

How does this new trait work?

A susceptible insect larva eats the Bt protein, which then binds to specific receptors in the larva's gut. Binding initiates a cascade of effects in the larva that ultimately leads to death.

Which pests does HERCULEX^® XTRA Insect Protection target?

The proteins expressed in the Cry1F, Cry34Ab1 and Cry35Ab1 genes are different from other plant-based Bt endotoxins currently registered and sold in seed corn, in that it protects the plant from several destructive corn insects, making HERCULEX^® XTRA Insect Protection the broadest-spectrum, in-plant insect protection trait for corn hybrids available today.

Cry1F, found in the HERCULEX I trait, offers protection against European corn borer, southwestern corn borer, western bean cutworm, black cutworm and fall armyworm, and intermediate suppression of corn earworm. Cry34Ab1 and Cry35Ab1, found in the HERCULEX RW Rootworm Protection trait, offer protection against northern, western and Mexican corn rootworm.

Because HERCULEX^® XTRA Insect Protection offers broad-spectrum protection, it is effective on many pests. How effective is it on the following pests?

European corn borer
In the central Midwest, European corn borer (ECB) can produce up to three generations per year. Each generation can do a great deal of damage to the corn plant, which reduces yield. HERCULEX^® XTRA Insect Protection is designed to stop the corn borer all season long, and will be of greatest benefit to growers in years when corn borer pressure is high.

Fall armyworm
HERCULEX^® XTRA Insect Protection provides excellent protection against fall armyworm. It provides superior performance than other transgenic Bt traits in the marketplace.

Western bean cutworm
HERCULEX^® XTRA Insect Protection is the only above-ground, in-plant insect protection trait that offers protection against western bean cutworm.

Black cutworm
HERCULEX^® XTRA Insect Protection provides very good protection against black cutworm. It is better than other Bts in the marketplace. Trials to date have centered on smaller barrier-type experiments. These trials simulate extreme pest pressure because no escape avenue is provided for the larvae. Additionally, high densities of large larvae are infested onto very young plants. Trials are ongoing that compare the efficacy of HERCULEX XTRA with insecticide treatments.

Corn earworm
HERCULEX^® XTRA Insect Protection provides intermediate suppression of corn earworm. It is a better option than conventional corn and is as effective as other Bt products in the marketplace.

Southwestern corn borer
Southwestern corn borer (SWCB) can be an important pest in the southern corn-growing regions of the United States. Second- and third-generation larvae cause the most damage. Annual losses of about 1 percent of total corn production are common. HERCULEX^® XTRA Insect Protection is designed to stop the corn borer all season long, and will be of greatest benefit to growers in years when corn borer pressure is high.

Corn rootworm
HERCULEX^® XTRA Insect Protection provides powerful below-ground, in-plant insect protection against western, northern and Mexican corn rootworm larvae. You get season-long 24/7 larval rootworm protection, even if you plant early or there's a late rootworm hatch. And no matter what part of the root system the corn rootworm larvae feed on, HERCULEX XTRA reduces corn rootworm larvae populations that survive and reach the adult beetle stage, including soybean variant western corn rootworm and extended diapause northern corn rootworm.

Is HERCULEX^® XTRA Insect Protection expressed in the entire corn plant, regardless of where pests feed?

Yes, HERCULEX XTRA^® Insect Protection is expressed throughout the plant, including the roots, stalk, leaves, ears, grain and silks.

How does plant protection offered by HERCULEX^® XTRA Insect Protection differ from that provided by conventional insecticide treatments?

HERCULEX^® XTRA Insect Protection is an in-plant, insect protection trait. The protection offered is more comprehensive than what's available from conventionally applied insecticide treatments, which must be timed appropriately.

HERCULEX XTRA provides full-season, full-plant protection. The protein trait continually protects the plant throughout the entire season – no need for added costs to apply insecticides and no missed spray windows. HERCULEX XTRA is not affected by environmental conditions, such as drought or misapplication. No insecticide on the market today can control the variety of insects, in one single application, that HERCULEX XTRA protects against.

Are there any risks to nontarget insects?

A number of nontarget organisms were tested as part of the registration process and no adverse effects were observed. Some of the organisms tested include honeybees, earthworms, lady beetles, springtails and green lacewings.

What impact does HERCULEX^® XTRA Insect Protection have on crop yield?

The fact that HERCULEX^® XTRA Insect Protection is a full-season, full-plant insect protection trait means that it protects yield all season long. The corn plant remains healthier. There is reduced damage to the crop and fewer broken or downed stalks. Ear droppage is reduced. Harvesting is more efficient. A healthy plant also can better fight off weather or environmental stresses throughout the growing season.

How do yields compare with non-Bacillus thuringiensis corn yields?

The presence of a Bt trait in a hybrid does not increase yield, it only aids in preventing yield loss due to insect damage. Yield potential is determined by the genetics of a hybrid. The better a plant is protected from insects and other stresses, the better it can realize its full genetic potential.

Do I need to be concerned about planting dates with hybrids containing HERCULEX^® XTRA Insect Protection?

All corn is vulnerable to insect pests throughout the growing season. However, early planted corn is more susceptible to first-generation corn borer and black cutworm. Late-planted corn is more severely damaged by second-generation European corn borer, southwestern corn borer, fall armyworm and corn earworm. Full-season, broad-spectrum insect protection will help limit damage and stress from insect pests and help hybrids reach their full genetic potential, regardless of planting date.

In addition to how an elite corn hybrid would be normally planted and managed, are there any other agronomic practices required in planting and managing hybrids containing HERCULEX^® XTRA Insect Protection?

There are no special agronomic practices needed in managing hybrids containing HERCULEX^® XTRA Insect Protection over conventional hybrids other than what is needed to satisfy Insect Resistance Management (IRM) requirements. A grower will need a plan developed for planting his acres so that all refuge requirements are met.

See the Product Use Guide for IRM guidelines.

What are the IRM requirements for HERCULEX^® XTRA Insect Protection?

See the Product Use Guide for IRM guidelines.

Are the Insect Resistance Management (IRM) requirements for HERCULEX^® XTRA Insect Protection different from other Bacillus thuringiensis?

The Insect Resistance Management requirements for HERCULEX^® XTRA Insect Protection are the same as for other Bt products.

See the Product Use Guide for IRM guidelines.

Hybrids containing HERCULEX^® XTRA Insect Protection also feature the LibertyLink^® trait. What’s the reason for this and why is it important?

All hybrids with HERCULEX^® Insect Protection feature the LibertyLink^® trait, making them tolerant to over-the-top applications of LIBERTY^® herbicide.

The phosphinothricin acetyltransferase (PAT) protein, expressed by the PAT gene inserted into plants containing HERCULEX XTRA Insect Protection, confers tolerance to glufosinate-ammonium herbicides. The PAT protein is an enzyme that catalyzes the conversion of the active ingredient in glufosinate-ammonium to an inactive form, thus detoxifying the glufosinate-ammonium herbicide. Plants possessing this tolerance can be sprayed with glufosinate-ammonium herbicides. These are a class of postemergence herbicides that are broad-spectrum, systemic and nonselective, allowing weed control after the emergence of the corn plants. You can use LIBERTY herbicide or stick with your conventional weed control program.

Are there other considerations when determining the value of HERCULEX^® XTRA Insect Protection?

The most direct benefit is protection of yield potential as a result of reduced insect feeding and damage. However, it's also important to keep in mind the less-measurable secondary benefits of the broader-spectrum, in-plant insect protection offered by HERCULEX^® XTRA Insect Protection. Knowing that your corn is protected can help you reduce the time spent scouting and worrying about treatment thresholds for the pests targeted by HERCULEX XTRA. While slight to moderate insect pressure may not kill a corn plant, insect feeding beyond the most superficial levels does stress the plant, thus reducing the likelihood it will reach its full genetic potential. This feeding also can provide entry points for other pests or disease, further stressing the plant. Pests that bore into or feed on stalks and roots can weaken the plant. The resulting lodging or dropped ears can slow harvest and reduce yields.

HERCULEX^® XTRA Insect Protection is a Market Choices^® product. What does this mean?

Grain harvested from products that bear the Market Choices^® logo are fully approved for food and feed use in the United States and Japan, but is not approved in the European Union (EU). Since EU import approval is pending, HERCULEX^® RW Rootworm Protection and HERCULEX XTRA are Market Choices products. Grain containing either product must be marketed domestically, fed on-farm or delivered to elevators or other markets where neither the grain nor its processed products (e.g., gluten) will be shipped to the EU.

Grain from hybrids containing HERCULEX I only is fully approved for food and feed use in the EU; however, this approval does not apply to grain (or processed products from this grain, e.g., gluten) from HERCULEX I hybrids stacked with Roundup Ready^® Corn 2. Grain from hybrids containing HERCULEX I and Roundup Ready corn is a Market Choices product and must be marketed accordingly.