Pick ’em right!
This year’s corn crop is made, or close to it, and most corn silage is packed away. And now comes corn picking — hybrid selection — for 2011.
Curtis and Eugene Lapp of Kinzers, Pa., have gleaned much from their test plots over the last 13 years. And the benefits have carried beyond Lapp Brothers LLC’s own 600-acre operation to a number of its custom planting and harvesting customers.
Striving for the best yields in the balance of narrower rows and higher populations can be tricky, says Eugene. Hybrid improvements make it “a moving target,” he adds. “Corn is being bred to withstand higher populations.”
• The Lapp Brothers’ plots found twin-row corn better than 30-inch rows.
• Reduced plant competition boosted silage yields by 2.4 tons.
• Increased silage digestibility was an unexpected surprise.
The Lapp brothers select mostly for silage corn. They’re committed to twin rows — 8 inches between twin rows, 22 inches between each set. That way, corn can be harvested with a row-independent chopper head or a 30-inch row combine.
Staggered plant spacing reduces competition for nutrients, water and sunlight. “Within the same hybrids and plant populations, we’ve found a fairly consistent 2.4-ton-per-acre silage yield advantage for twin rows over 30-inch rows,” Eugene adds.
“That’s about 10%. This year, we expect differences in hybrid heat tolerances to be a bigger factor.”
Six years ago, the brothers started testing 32,000, 35,000 and 38,000 plant populations. “That year was a little dry, and the 32,000 plant stand was best,” reports Curtis. “So the next year, we went to 29,000, 32,000 and 35,000 plants per acre in a more normal season. Again, the 32,000 stand was best.”
The big surprise
Today, the Lapps shoot for silage corn populations of about 33,000 plants per acre. The twin rows, plus an April 20 optimum planting date, “will give us a bigger stalk,” suggests Eugene.
Decreasing in-row plant competition helps build a larger stalk. “Doing so reduces the proportion of outside rind [lignin] and increases silage digestibility. That was a surprise,” he adds.
The Lapps’ planter setup also plays a role in growing that bigger stalk. Their Great Plains YP1225 planter injects a maximum rate of 30 gallons of liquid nitrogen between the twin rows. It also places row support, or pop-up (not starter), in-furrow. The latter product consists of 4 gallons of 3-18-18 plus 2 quarts of Side-Kick (0-0-25-17S) and 10 ounces of Soil X-Cyto.
“This program has shown a 2.7-ton advantage per acre over the last 12 years,” notes Eugene. “Those nutrients are there when the corn sends out that first root shoot.”
This article published in the October, 2010 edition of AMERICAN AGRICULTURIST.