Iowa Farmer Today
08-23/07
Seed corn hybrids stacking traits
By Tim Hoskins, Iowa Farmer Today
This fall, some seed corn companies will be promoting a “quad stack” in their
hybrids.
For example, Syngenta recently announced it will offer a quad stack for the 2007
growing season. A quad stack features four biotech traits — Liberty Link,
Roundup Ready, corn borer and corn rootworm resistance — in the hybrid.
Syngenta says its quad-stack hybrid has full U.S. government approval for
planting in 2008. The company is seeking full regulatory approval in Japan and
other major export markets.
One of the selling points of the quad stack is a way to add some flexibility for
farmers.
Mike Owen, Iowa State University weed management specialist, says the
technology might help eliminate some of the problems he has seen in the past
couple years.
“It would help eliminate some of the ‘oops’ that we have had in the past couple
years,” he says.
The “oops” Owen talks about is the problem of a wrong herbicide being sprayed
on a crop. For example, if Liberty was sprayed on Roundup Ready corn or
Roundup was sprayed on a Liberty Link field.
He says one potential problem with using a hybrid with Roundup Ready and
LibertyLink traits in it is how to kill it for replanting. Other herbicides would be
able to kill the stand, Owen notes.
If the corn is planted in mid to late April and then a herbicide with a residual is
applied to kill the crop, Owen says that means it will be the mid to late May into
early June before the field could be replanted to corn.
Other states have sponsored section 18 labels for herbicides to take out a crop
that already has LibertyLink and Roundup Ready genes in it.
LibertyLink is a marker for the Herculex trait. Therefore, a Herculex corn hybrid
should have LibertyLink in it.
Some of the hybrids that have Herculex in them also are Roundup Ready.
So, a hybrid that has more than three stacked traits in it is not a new concept.
However, Owen says using the two herbicides could provide a good way to
control any glyphosate-resistant weeds because a farmer can use both
herbicides. More promotion for hybrids with resistance to two herbicides is not
the only new technology farmers will see this fall for the 2008 growing season.
Monsanto will be promoting its YieldGard VT program. The YieldGard VT uses
vector stacked transformation or “VecTran” as a way to insert genes with more
precision than a gene gun, according to company officials.
In 2007, 316 Iowa farmer grew hybrids in the YieldGard VT program. In total,
about 1.5 million acres were planted in the United States in 2007.
The company plans a significant expansion for the 2008 growing season.
On the web:
Syngenta: www.syngenta.com/en/products_services/field_crops.aspx
Monsanto’s YieldGard VT site: www.yieldgardvt.com