New trait-stacked technologies will be coming on the market soon for use by corn growers, and are aimed at controlling above-ground corn insect pests. The products will give more options to growers who need to control lepidopteran pests, but don't need rootworm protection, notes Clarke McGrath. McGrath writes the Corn/Soybean Insight column which appears in each issue of Wallaces Farmer magazine. He provides the following observations and information he's gathered regarding these new products that are being readied for the marketplace. You'll probably see them being demonstrated in field test plots in summer 2014.
* Optimum Leptra—this trait is new from DuPont Pioneer. Foliar feeding, stalk boring and ear feeding corn insect pests are the target; this trait combines Optimum Intrasect (Herculex I (Cry1F) + YieldGard Corn Borer (Cry1Ab) with Agrisure Viptera (Vip3A).
Corn hybrids that will have the new Optimum Leptra trait will also contain traits for tolerance to glyphosate and glufosinate herbicides.
This year corn hybrids with this new trait will be targeted for growing in the southern U.S. corn production areas with 113 to 118 relative maturity corn hybrids. The word from the company is we'll see corn hybrids with this trait targeted to Iowa's maturity zone coming on the market for 2015, says McGrath. The hybrids will require the planting of structured refuges of 5% in the Corn Belt.
* Powercore—this trait is new from Dow AgroSciences. It targets European corn borer, southwestern corn borer, corn earworm and fall armyworm with a combination of three proteins: Cry1A105, Cry1Ab and Cry1F.
Powercore is SmartStax without the corn rootworm traits. Anticipated launch for this above-ground triple stacked trait is the 2015 growing season, pending additional regulatory approvals. It will be offered as a 5% refuge-in-the-bag product in the Corn Belt, says McGrath. "We may see it in plots during the 2014 crop growing season, but it sounds like a full launch of the new product won't be until 2015. Pending regulatory approval, current indications are that corn hybrids that will have this trait will also carry glyphosate and glufosinate herbicide tolerance."~~~PAGE_BREAK_HERE~~~
* Agrisure Viptera 3110—Syngenta has added true armyworm to the list of above-ground pests controlled by this trait. This trait stack has been on the market for several years, however the EPA recently granted approval to have true armyworm added to the list of pests that this trait controls.
According to Syngenta sources, it is the only trait stack to control true armyworm. The proteins included in this trait stack include Cry1Ab and Vip3A and includes both glyphosate and glufosinate herbicide tolerance. A 20% refuge will be required to be planted.
Cover crop observations—ISU agronomists are getting quite a few questions about cover crops
ISU Extension field agronomists are still receiving questions about cover crops. McGrath shares the following observations from what he and his colleagues saw this fall in the ISU cover crop plots he's involved with in southwest Iowa.
The drought of 2013 took a toll on some of the plots. "While I tried to seed the plots we have here in our area ahead of predicted showers, in some cases that created problems," notes McGrath. "Where we had a rain that resulted in only a few tenths of an inch of moisture, some seeds imbibed water, started to sprout and then when the heat and dry weather returned, the seeds desiccated and died. Looks like the lentils and vetch species took that pretty hard, but it impacted all of the cover crop species to a degree. Most of the stands aren't as thick or as tall as we'd expect in a 'normal' year."
* It looks like wider bean rows were easier to get cover crops established in this year. In the 15-inch row width beans, the cover crops that were aerially seeded into these narrower row beans didn't get a lot of growth in some areas; the cover crops seeded into the 30-inch row width beans look a little better.~~~PAGE_BREAK_HERE~~~
* Today's soybean harvesting platforms on the combines trim back the cover crops quite efficiently. This year the cover crops did grow back pretty well in many plots, even with the later harvest. "We had to run the platforms low to the ground since the beans set pods close to the soil surface," says McGrath. "The cover crops essentially got 'mowed off' a few inches tall. In a perfect world we'd have the beans set pods higher so that we didn't cut any leaf surface off the cover crops, but there isn't much we can do about where soybeans set pods. The good news is that today's bean platforms with better sickle sections do a great job of trimming so the cover crops can regrow, rather than tearing them out of the ground."
* The drought also meant that "some of our residual herbicides may have hung around a little longer than usual," says McGrath. "I have some plots where the stands—and lack of stands—could be related to residual herbicides. Or it could have been the erratic rainfall patterns, or both. Our experiences and observations are about all we have to guide us here, since most herbicide labels are pretty vague when it comes to cover crops and rotation intervals. We hope to take a look at the same plots again next year under more favorable rainfall conditions and see if this was an anomaly."
* As expected, cereal rye and tillage radish looked good in most areas; a pleasant surprise from a ground cover standpoint was mustard. "Some plots had nearly 100% coverage last time I saw them, and it was pretty impressive," says McGrath. "I'm interested to see how those stands will look after the extended cold spell. In fact, I just returned from taking some of the late November readings, and it was cool out there! I happened to be in some plots that didn't have a lot of growth to start with, and they are essentially barren now. I still need to evaluate the plots that had much more growth, and we'll see how they fared."