By DOUG GRAVES
WILMINGTON, Ohio — The idea of reaping 300 bushels of corn per acre may still seem like a pipe dream, but with technology and plant science getting more refined each year some experts say it may be commonplace in the near future.
Dr. Peter Thomison, Ohio State University horticulture and plant science expert, says there are seven key management factors involved when maximizing corn yield: hybrid selection, crop rotation, tillage, planting site, stand establishment, plant population and row spacing.
“In order to see 300 bushels by 2030 we’d have to produce 7.4 bushels more per acre per year from this point on,” Thomison said. “That would be quite tough to do. But our corn production has increased steadily since 1930 so that by 2030, we should at least reach 214 bushels per acre.”
Thomison addressed farmers from six counties during the first Southwest Ohio Corn College in Wilmington last week. He said corn yields saw a huge jump in what he called a “transgenic era”, a 20-year span from 1990-2010 when corn hybrid technology made huge impacts on yields.
“Yields have increased in part due to better pest management, pest resistance and upright leaves, but the new hybrids nowadays have better stalk quality, and that’s been the biggest difference,” he said.
“Comparing crops from the 1930s, crops nowadays have high plant populations and this is due to the changes in root structures from these new hybrids. Hybrids of today have better, deeper root systems.”
Hybrids, he says, accounts for 17-24 percent increase in corn yields. In looking at crop rotation, Thomison said the numbers can be “astonishing.
“Crop rotation increases yield from 4 to 18 percent depending on tillage,” he explained. “Response to tillage was greater in continuous corn. Crop rotation can be a major asset.”
Thomison said the planting dates of corn are crucial as well.
“Ohio farmers should complete planting by May 10 at the latest,” he said. “Ideally, in the southern part of Ohio it’s best to plant corn between April 10 and May 10. With early planting you have reduced exposure to late-season pests and have better stalk quality. The earlier you can plant corn the better.”
Stand establishment, he said, is another vital aspect of reaching higher corn yields. “It is really important to minimize uneven spacing variability within the rows, eliminate crowding of plants and reduce uneven emergence,” he said.
“When you have big gaps in rows you naturally have more incidence of weeds, and this can have a great impact on yields. In addition, the competition from larger, earlier-emerging plants can influence the performance of smaller, later-emerging plants.
“If there’s one concern or observation from crop consultants, it’s with planting depths,” he said. “I realize planting depths is a real challenge for growers, especially those with large planters. Under normal conditions, one should plant corn 1.5 to 2 inches deep, planting seeds slightly shallower in April and slightly deeper in May plantings.”
In closing, Thomison said narrow rows of corn may reduce plant-to-plant competition and increase yield, especially with higher populations in some environments. And, there is no proof that twin-rows are any better than conventional single-rows.
“We have to look at the interaction among the seven factors,” he said. “If we can hit on the right interaction and right combination of these factors, we can get that high yield. And all this is influenced by weather conditions.”