1/28/2013 11:34 AM
By Charlene M. Shupp Espenshade Special Sections Editor
EAST EARL, Pa. — Winter might be here, but farmers have already started making plans for spring planting. Seed catalogs are full of different corn hybrids or forage varieties. But how to pick?
Everett Thomas of Oak Point Agronomics says it’s about picking the variety that will generate the best yields for your farm.
“Don’t assume the newer (corn) varieties have the better fiber digestibility. Some do, most don’t. Rely on trial data. Most of the improvements have been in the ear, not the stalk,” he said. “Look at the trial data so you know what you are doing.”
Thomas spoke at a REB Dairy Consulting Seminar on Tuesday at Shady Maple Restaurant, East Earl. He has been an agronomist for 46 years and previously worked at the William H. Miner Agricultural Research Institute in Chazy, N.Y. for 27 years.
“You need to understand the (corn industry) is based on grain,” Thomas said, explaining that nine seed corn varieties out of 10 are intended for corn grain harvest.
“The real market for silage corn is about 5 percent,” he said.
To find the right silage variety, farmers need to use corn silage variety trials to gather information on forage quality, Thomas said.
Universities such as Penn State, Cornell and Virginia Tech have done trials, and the results are available online through their Extension programs.
Charting the quality changes over the past 50 years, corn grain quality has advanced, but corn stover has remained virtually unchanged.
There are three types of corn hybrids — conventional, leafy corn and brown midrib (BMR) — available for planting. Conventional remains the most popular choice.
When selecting a conventional variety, the difference from the best to the worst comes from grain yield. Thomas suggests selecting a hybrid for yield and total digestibility, and not to worry about fiber digestibility.
“There was about two points between the best and the rest” in fiber digestibility, he said.
“Leafy hybrids have become very popular in dairy country,” he said, cautioning, however, that university trials have not found any difference from conventional hybrids in yield, silage quality or milk production advantage.
One difference with some varieties is a longer harvest window, he said, and farmers who use a custom harvester or run the risk of harvest delays might see this as an advantage.
BMR corn is “different” from its hybrid counterparts. The midrib has a brown color and lower lignin, and its forage quality is higher. It is designed for silage production.
“It is a small but growing percentage of silage sales,” he said.
Mycogen has sold BMR varieties for several years. Pioneer has released its first variety.
Thomas said in the 2011 Penn State trials, individual BMR hybrids varied between 59 and 94 percent of non-BMR hybrid yields.
“There have been real stinkers,” he said. “Hybrid selection is critical.”
BMR hybrids should be planted on a farm’s best soils, Thomas said, and something else should be selected for thin or droughty soils. BMR hybrids do not like dry conditions.
“You need to figure out where you are going to feed it,” he said.
With the slightly lower yields and higher seed costs, it pencils out very well for high production group rations, he said.
However, it’s a much more expensive option for dry cows, low production cows or heifers. Farmers also need to have a separate storage for BMR silage.
“You need to match the genetics to your particular farm situation,” he said.
Thomas also spoke briefly about alfalfa and grasses. He said alfalfa has been flat-lined for yield and quality until recently. Most advances have been for disease and pest resistance.
Hybrid alfalfa still has some yield drag but is improving. Trial testing on several hybrids has begun in New York, he said. The trial includes leafhopper resistant hybrids pitted against the best nonhybrids.
“There is a yield drag, but this one is reasonable especially if you have a situation such as (leaf hopper infestation),” Thomas said.
He said some new hybrids are showing good potential in forage quality without penalizing yield.
“Keep your eye out on this stuff, folks,” he said.
In contrast to corn, soybean and alfalfa, “grasses are boring,” Thomas said.
However, grasses need a second look, especially for cropland that does fit well for alfalfa production. It performs better on heavy soils, and grass works better with high corn silage rations, he said.
Orchardgrass is common in Pennsylvania, but Thomas cautions that it looses quality after heading.
Reed canarygrass will tolerate high manure rates, but does not hold quality.
Tall fescue has new varieties available on the market. The difference is in yield, not quality. Only use endophyte-free varieties, he said.
No matter what type of grass, he said, harvest management results in stand quality. Energy storage in grasses happens in the lower part of the plant. A 4-inch stubble is needed.
Alfalfa can be cut shorter, because its energy storage is in the taproot.
“If it’s cut too tight, it will kill the grass,” Thomas said.