With corn prices continuing on the upswing, growers are naturally interested in upping the ante by boosting acres and yields.
“About a year and a half ago, we were excited that the price of corn had reached $3.50 per bushel. Now, some growers are upset they sold corn at $3.25, so we’re definitely looking at things differently,” says Chad Lee, University of Kentucky grains specialist.
Futures prices for corn are looking good, with some producers locking in corn at more than $4 per bushel and still wondering if they pulled the trigger too soon, says Lee. “So we have a lot of interest in the crop and tremendous pressure from input prices, with nitrogen prices at about 50 to 55 cents per pounds,” he says.
Speaking at the Alabama Corn and Wheat Conference in Huntsville, Lee said Alabama corn yields have increased fairly well by about 2 bushels per year over the past 20 years.
“Yields took a bit of a hit last year. In 2007, we proved once again — throughout the Southeast — you have to have water to make a crop grow,” he says.
When growing corn, producers need to look at “the big picture,” says Lee, or all of the things that go into making a successful crop.
“This is not in any particular order, but we start off with good genetics, then you maximize days suitable for growing. Then, you need 90 to 95-percent light interception at silk — you need a full canopy at silking. You also need adequate nutrients, water and air to complete plant growth and seed fill. Everything you do in your system to grow corn is affected by one of these areas if not more,” he says.
Good genetics, says Lee, includes good yield potential and stress tolerance. “When we talk about maximizing suitable growing days, we’re talking about maturity ranges, stress tolerance and planting dates. Light interception includes such factors as row spacing and seed population. Planting date and immaturity also can affect this. Late planting dates and shorter maturity groups can present a challenge in getting 90 to 95-percent light interception. In a year like this past year, with dry conditions, we have a difficult time getting full canopy covers,” he says.
If a grower is in a rain-fed, non-irrigated situation, there’s not much he can do about the amount of water that lands on his fields, says Lee. “But you can do some things to your soil to affect water infiltration and water availability. Within limits, you can do some things to help make water more available to that crop,” he says.
Corn growers, says Lee, can’t afford to focus on just one area of production. “There’s more that goes on than just genetics, fungicides or seed treatments. In your own operation and fields, you have to look at where your limitations are, and you need to focus on those areas first if you’re going to improve your yields,” he says.
Turning to hybrid selection, Lee says relying strictly on a brand name doesn’t guarantee that you’ll get high yields.
“We have a lot of questions about hybrid traits such as Bt and Roundup Ready, and whether or not they give us a yield improvement,” he says.
Looking at a north Alabama test from 2006 that included 57 hybrids, Lee says that of the Bt III varieties in the test, two were within the top yielding of all varieties and two were within the bottom yielding.
“If you’re looking at hybrids, and you’ve selected a Bt III hybrid, you have a 50/50 chance of getting one that is good or one that is a ‘dog.’ The point being that the trait at the end of the hybrid doesn’t necessarily guarantee excellent yields.
“The advertisements out there now are showing these new stickers being put at the end of a hybrid’s name, and that’s being marketed to us as giving us good yield. But you can put stickers on a lot of different things and still have different levels of performance — it doesn’t make it high yielding. A lot of hybrids that have those traits are high yielding, but you have to look for that trait.”
Growers should follow the basic IPM methods when targeting pests on their corn crops such as seedling insects, says Lee. But one of the big questions now involves the use of seed treatments.
“And sometimes now, you don’t have an option other than high dose or low dose — there is not untreated. Hopper box treatments become less of an issue as options have narrowed on what you can’t put on the seed. Different seed treatments have been evaluated by the University of Kentucky, looking at white grubs, flea beetles, seed corn maggots, cutworms and root worms. If you’re in a rotation, you may not have to worry about rootworms or other insects.”
The three groupings of insect-resistant corn include YieldGard, Herculex and Agrisure, he says.
Turning to foliar fungicides, Lee says research has shown a favorable response from their use only in conditions that are favorable for the development of disease. “If you have several things working against you, the need to spray a fungicide increases. For example, if you’re planting a susceptible hybrid in no-till conditions and you’re planting late and under irrigation, it might be to your benefit to use a foliar fungicide. In one field, we saw a 70-bushel difference in favor of using a fungicide.
“But if we’re in conditions where disease doesn’t show up, we haven’t seen enough data that would prove to us that we get a yield increase if we use a fungicide.”
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