CropTech: Take Stock of Stalks

Take Stock of Stalks

Cornstalks just aren’t what they used to be. While they’re still an inexpensive way to graze cattle, producers are now reporting that stock doesn’t fare as well on today’s stalks.

Bruce Anderson, University of Nebraska–Lincoln Exten-sion forage specialist, says the changes started a few decades ago when modern combines became more efficient at collecting grain.  Harvest losses usually run around 2% or less today, compared with around 4% or more in days gone by. Less grain left in the field means cows will need supplemented feed earlier.

Today’s stalks may also be less nutritious, Anderson says. Modern hybrids draw more nutrients out of the stalk and into the kernel. He adds that hybrids which have been genetically modified to resist insects and reduce lodging produce stalks that may be less palatable and provide fewer digestible nutrients.

Today’s cows are larger and need more forage—and often more supplementation—than the smaller cows of yesteryear. "A quarter section of stalks won’t carry as many cows as it once did," Anderson says. "Even when stocking adjustments are made, if supplements aren’t also adjusted, cow performance may suffer."

Scout Like a Master

Most farmers are just having their first cup of coffee when Charlie Hinkebein is heading to the field to look for whatever insect might be eating his crops. The Chaffee, Mo., farmer is a perennial corn and soybean yield contest winner. He says the recipe to achieve 100-bu. soybean and 300-bu. corn yields includes an aggressive pest scouting program.

"I usually head to the field before 5 a.m.," Hinkebein says. "It seems like that’s when bugs and worms come out and start moving around.

"In my experience, insects crawl up under leaves or even go underground during the heat of the day. It requires the use of drop cloths and some real shaking to find what’s out there after midday," he says.

Typically, he’s hunting for soybean aphids and bean leaf beetles. A tough new nemesis—the
red-banded stink bug—showed up this past year.

Insecticides are an important part of Hinkebein’s yield-winning recipe, but scouting is still a requirement. Windshield surveys don’t cut it.

Hinkebein personally scouts each of his fields at least twice and sometimes three times a week during the growing season.

His other secret to yield success is test plots. Hinkebein devotes about 250 acres to testing new corn and soybean varieties each year.

Fungicide Timing Matters

Fungicide spraying has become an effective way to control corn leaf disease and protect yields. The debate the past few years has revolved around when to apply fungicides.

Many fungicide labels prohibit applications sooner than VT (full tassel). However, University of Illinois plant pathologist Carl Bradley says, some companies have begun encouraging an earlier foliar fungicide application in the V4 to V6 crop stage.

Results from a 2010 study conducted by Eric Adee at an University of Illinois research farm in Monmouth, Ill., show a slight yield increase with a V5 application, but Bradley says it was not statistically different than the non-treated control and had no effect on disease severity measured at the end of the season.

"In that trial, fungicide applied at VT or R1 applications provided a statistically significant yield increase compared with the nontreated control," Bradley says. "In addition, the VT and R1 applications significantly reduced disease severity compared with nontreated control."

Bradley recommends applying fungicides at R1 when disease risk and scouting observations warrant. "More research is needed on V5 applications, but in the data that is available, R1 applications appear to be better," he maintains. "I’m urging any growers who try these early V5
applications to leave nontreated check strips so they can determine for themselves if it was an advantage."

Refuge Reminder

If you grow Bt corn this year, you must plant a refuge. It makes no difference what brand or trait combination you plant—every single traited seed corn on the market requires a separate refuge in 2011.

There have been a lot of news reports and excitement about reductions in corn refuge lately. However, most of the new reductions aren’t expected until 2012.

The smallest refuge acreage available for 2011 is SmartStax, the trait platform developed by Dow
AgroSciences and Monsanto Company. SmartStax hybrids currently require a 5% refuge adjacent to the field where the stacked trait package is planted.

Monsanto’s Genuity VT Double Pro also requires a 5% refuge, with a wider ½-mile stipulation.
For 2011, DuPont business Pioneer Hi-Bred has a version of the in-the-bag concept to market called Optimum AcreMax 1. The base recipe for AcreMax 1 integrates 90% of a Pioneer brand hybrid with Herculex Xtra (CRW/CB/LL/RR2) and 10% of a Pioneer hybrid of the same genetic family containing the Herculex 1 trait (CB/LL/RR2). "The 10% Herculex portion satisfies the grower’s corn rootworm refuge requirement," says Bill Belzer, Pioneer senior marketing manager for corn.

This season, however, growers must still plant a 20% corn borer refuge with the AcreMax 1 system. Belzer says that requirement is simplified because the corn borer refuge can be planted as much as ½ mile away, allowing dedicated refuge fields rather than needed adjacent plantings.
The 20% corn borer refuge can be planted with conventional or herbicide-tolerant hybrids. Those who want 100% corn rootworm trait protection have access to another in-the-bag option via Optimum AcreMax RW. The seed contains 90% of a Pioneer brand hybrid with Herculex RW and 10% of a Pioneer hybrid with RR2 herbicide tolerance.

Pioneer recently announced a new Optimum Intrasect product that reduces the 20% aboveground refuge to 5% (20% in the Cotton Belt) within the ½-mile parameters. Again, don’t be confused—this Intrasect product is a 2012 product. It will be used in on-farm trials in 2011 and commercially available in 2012. By then, Belzer says, Pioneer anticipates approval of its next-generation, single-bag approach.

Until the 2010 growing season unfolded, a structured 20% refuge requirement was the primary resistance management option for insect pests across the Corn Belt. Most Bt hybrids still require this 20% refuge.

The National Corn Growers Association has developed a calculator to help clarify the refuge system options and show growers how to properly execute the requirements. Access the IRM (Insect Resistance Management) Calculator at http://ncga.com/irm-calculator.

It's Not in One Bag Yet

Plenty of farmers are chomping at the bit to have the refuge totally integrated in the bag. Have patience.

University of Illinois Extension entomologist Mike Gray says pyramided products that stack multiple modes of insect protection together are starting to change how refuges will be handled in the future.

"I believe it is only a matter of time before seed mixtures [Bt and non-Bt] form the foundation of resistance management plants for corn rootworm and lepidopteran insect pests across the Corn Belt," Gray says.

Each company has a unique name for its integrated refuge product. Monsanto Company’s refuge-in-a-bag will be marketed as Genuity SmartStax RIB Complete and Genuity VT Double Pro RIB Complete. Dow AgroSciences will bring forth SmartStax Refuge Advanced.

Syngenta Seeds has submitted the Agrisure 3122 E-Z Refuge trait stack to the Environmental Protection Agency. Pioneer Hi-Bred’s totally integrated product will be called Optimum AcreMax and Optimum AcreMax Xtra.

None of these products are anticipated to see commercialization until 2012 at the earliest. "Until then, continue to follow an integrated insect management plan," Gray says. "Following refuge requirements is important for the commercialization of next-generation biotech traits."

Southern corn growers especially will need to monitor the situation for refuge requirements. Bt cotton acreage has traditionally influenced the percentage of refuge that must be grown, and refuge percentages vary. Integrated in-bag options may not become a reality in some Southern cotton growing areas.