When North Carolina State University Corn Specialist Ronnie Heiniger says corn is a miracle waiting to happen in the Southeast, farmers pay attention.
Heiniger, a Midwest grain farmer by birth and a North Carolina corn specialist since 1992, says 2009 was one rain away from having a miracle crop. Despite some ill-timed rain, he notes that the 54 entries into last year’s statewide Corn Yield Contest averaged 225 bushels per acre and 20 entries topped 250 bushels per acre.
H&H Farms in Greene County, N.C., claimed dryland corn yield honors last year with 314 bushels per acre. They also claimed top honors for irrigated corn with 399 bushels per acre.
Charles City, Va., growers David and Johnny Hula have consistently topped 300 bushel per acre for a number of years, so 400 bushels per acre tops and 200 bushels per acre average isn’t a pipe dream.
North Carolina wasn’t much different than other states in corn production last year. Nationwide corn production topped 13.2 billion bushels, 1 percent above the previous record set in 2007, and 9 percent higher than 2008.
Corn yields reached an all-time high in 2009 at 165.2 bushels per acre, eclipsing the previous record of 160.3 bushels per acre set in 2004. Planted area, at 86.5 million acres, is the second highest since 1949, behind 2007’s 93.5 million acres.
In North Carolina and much of the upper Southeast, production could have been higher, according to Heiniger. “If we had gotten rain in June instead of July last year many of these yields would have been even higher. Last year irrigated corn made about 100 bushel per acre difference in some parts of the state,” Heiniger says.
“Just a very few years ago 300 bushels per acre seemed unreachable, now we’re pushing toward 400 bushels per acre. What’s looming in the future, may truly be a miracle,” Heiniger contends.
Five factors, he says, will determine whether growers are able to push onto a new frontier of corn production:
• Hybrid selection. New varieties are coming to farmers and getting into production faster than any time in history. Along with the good, comes the danger. Large companies are pulling out of variety testing programs, often leaving growers with too little data to base planting decisions. To take full advantage of these varieties, growers must be able to separate base genetic characteristics from trait characteristics.
For example, two years ago one particular triple stacked hybrid looked great, out-produced everything in the test. Last year, same variety, same site, same production practices and the same triple stacked hybrid was no better than a number of other hybrids.
• Plant populations. Plant population is a critical factor in corn production, especially when corn is being grown on dryland conditions. New, more drought tolerant corn cultivars have become available, these advances in corn genetics allow growers to increase plant populations slightly — in some cases.
Plant populations should be selected according to the soil moisture-holding capacities of individual fields. Corn plant populations per acre should increase with increasing soil moisture holding capacity. On soils with good to excellent soil moisture holding capacity, (bottom land) growers should seek to obtain a maximum of 26,000 plants per acre.
• Starter fertilizer. To raise a high yielding crop, Heiniger emphasizes a grower must put a corn crop in the ground with a good root system. The best way to do this is with starter fertilizer. “In 2009, North Carolina corn growers did the best job of getting corn up quick and growing since I came to the state in 1992. That’s a big part of the reason for such a good jump in yields,” he says.
Phosphorus is critical to root growth and shoot size. Getting phosphorus to an adequate level is the first step, then nitrogen becomes the critical factor in a starter fertilizer. Getting a good root system is critical to getting bigger ears and more kernel fill, which in turn is critical to high yields.
• Ear size is critical to yield. Though ear initiation does not occur until about V5 (Vegetative Growth Stage 5), early stress that results in stunted or weakened plants can have a negative effect. The most likely cause of small or misshaped ears is from stress at the V5 to V12 stage. If photosynthesis is limited, reduced ear size and number of rows of kernels can be negatively affected.
Heiniger says research he conducted in 2007 and 2008 indicate to him that by combining a starter fertilizer with management practices that increase early root growth, a larger root system can be developed. Larger root systems enhance early plant growth, resulting in larger ear size, better stress tolerance, less lodging and greater yield.
• Use fungicides wisely. At high seeding rates and using high rates of fungicide does not always result in increased economic benefit, according to Heiniger. However, when growers use hybrids that have little or no resistance to disease, significant yield and quality improvement have been attained using fungicides.
All of the keys to improving corn yield are inter-related, Heiniger says. The farmer must know his soil’s capability and understand how a corn plant grows to take maximum advantage of the new hybrids. Choosing the right variety is critical, but so are the other factors that go into maximizing corn production, he adds.
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