Outside Rows Outperform Inside Rows, Even in Dry Year

No neighbor on one side helps corn plants.

Published on: Sep 19, 2007

All results aren't in from the Corn Illustrated plots sponsored by Farm Progress Companies and Indiana Prairie Farmer. Irrigated plots remain to be harvested, since moisture levels were much closer to normal, and more than double that of the same hybrids in non-irrigated plots that simply ran out of water and died prematurely.

But already, interesting information is coming in. In one small plot study, in an unreplicated, demonstration check with the same hybrid, the outside row outyielded the next row in by 30-40%. Exact yields have yet to be corrected for moisture levels.

The surprising thing is that the outside row wasn't in wide open space. There was another corn row, but it was 60 inches away instead of 30-inches. One row was left intentionally blank both to gather this type of information, and facilitate managing the plot.

It was also noticeable to anyone who visited the plot, that the first couple plants on each end of the 1/1000th acre rows, consisting of 17 feet, 5 inches in 30-inch rows, put on and matured bigger ears, sometimes substantially bigger. There was a five-foot gap, again 60 inches, between these plants and their closest neighbor to one side.

These finding agree with past studies, notes Dave Nanda, president of Bird Hybrids LLC., Tiffin, Ohio, and consultant for the Corn Illustrated project. Nanda has forty years of plant breeding experience with a number of companies, most recently Stewart Seeds, Greensburg, Ind., now part of the ASI group. ASI is owned by Monsanto.

"We've known that outside ears perform better, and we've known it fro a long time," Nanda says. "It's a matter of more available sunlight."

This year, it was likely also a matter of more available water. All yields in the plot were reduced about 50% from normal. The soil in the plot field consists of three feet of loam over gravel. Plants eventually ran out of water when it quit raining in late July and early August. Soil reserves were already depleted by that point, with only marginal rain since May 1.

The practical application of this phenomenon is to try to get more outside rows, or better space plants to utilize sunlight and nutrients. Twin rows are one option. Nanda has experimented with equidistant spacing in 10-inch rows. However, harvesting equipment is still an issue. Planting equipment is available form Great Plains Manufacturing to plant in 10-inch or twin rows.

Scott Beck, Beck's Hybrids, Atlanta, Ind., is trying another approach in his practical research plots this year. He's continuing studies with corn and soybean strips. It's well documented that six to eight rows strips of corn alternated with soybeans yield significantly more than solid 20-inch rows. The drawback is that soybeans usually yield less, often enough less to offset potential gains in corn yield.

Beck is experimenting with ways to reduce the soybean loss, while maintaining the boost in corn yield. Look for reports on his efforts this year later in the season, after his plots are harvested.