by Larry Kershner
Farm News, Editor
AMES – In 2016, Central Iowa Agronomics, based in Ames and lead by Bob Streit, ran cornfield test plots with clients whose corn fields topped 285 to 300-plus bushels per acre for two years running.
This Central Iowa corn was still green and filling grain on Sept. 20, long after neighboring fields had died. The field was sprayed with Bio Empruv at tassel which researchers claim kept the plants growing longer and reaching a full maturity.
Soybean fields are yielding 87 to 92 bpa.
In fact, in one central Iowa corn field, Streit said they hit 265 bpa in soil with a CRP rating of about 35.
Streit and a number of other researchers are using a coordinated field management approach that includes soil testing; timely, split-application fertilizer practices; intense scouting and tissue sampling – basically assuring they know at all times what the plant needs now, will need later and be supplying those nutrient needs throughout the growing season.
Through this approach, Streit said they are giving the plants what they need to fight off diseases and resist insects.
Goss’ wilt
According to Don Huber, a 40-year member of the U.S. Threat Pathogens Committee, U.S. grain growers are dealing with a series of new and re-emerging diseases.
One of those, Goss’ wilt, which he said was formerly considered “a wimpy disease,” is more aggressive than ever and “threatens our sustainability.” It is seed-, wind-, water- and bug-borne and is endemic to North America.
Goss’ wilt causes an estimated $4 billion annually in lost U.S. corn yields. Until 2009, it was limited to a few counties in Colorado and Nebraska when it jumped to Pennsylvania and Manitoba, in Canada, and today is in every U.S. state, because it is in every corn seed that is planted.
Huber said this disease is more virulent as a result of genetic engineering.
“In order for corn to express tolerance to herbicides and Bt characteristics,” Huber said, “breeders had to use hybrids like A632 and B14.”
But these hybrids were also highly susceptible to Goss’ wilt, he said.
Tying in the fact that fungicides and herbicides bind seven genetic characteristics that allow corn to resist a relatively weak disease like Goss’ wilt, Huber said, “We are creating a favorable environment.”
Micro manage
This is where micronutrients come into the healthy plant discussion, Streit said. Goss’ wilt has been killing corn plants early for eight years.
In mid-September 2016, Streit said the USDA reported that 70 percent of Iowa corn plants were dead before reaching maturity.
But through timely applications of micro and macro nutrients, he said fields that were treated with a product called BioEmpruv were green and still in grain fill in late-September.
Corn fields in Carroll and Story counties that were treated hit 285 to 300 bpa field average.
In a Guthrie County field, that had a history of corn dying early, a 113-day hybrid planted May 6 received a foliar treatment of BioEmpruv at tasseling. The corn was still green and healthy on Sept. 14.
In a corn-on-corn field, where the best historical corn yield reached 225, BioEmpruv helped the plant yield 275 bpa as a field average.
High-yield psychology
Streit said his Central Iowa Agronomics uses a high-yield psychology with its growers.
Anyone can raise average yields, he said. It’s like playing checkers, but if you’re going to move up the yield ladder with corn, soybeans or wheat, the planning and execution process becomes more of a chess game, where there are more moving parts, products and interactions that need to be coordinated.
Row-placed fertilizer, timed nutrient applications, proven biologicals and emerging hormonal inputs and products all have a role in producing higher yields.
Building a knowledge base is important, as is having a team of crop advisors that can lay out a plan and provide guidance for each step as needed during the season.
Streit said he seeks growers to challenge themselves on a few fields to test these concepts and see which steps produce the best return on investment.
No silver bullet
Streit warned that the secret to reaching ultra-high corn and soybean yields goes far beyond timely micronutrient applications.
In fact, most Iowa fields by themselves are not capable of exceeding 180 to 220 bpa.
“There is no silver bullet,” he said.
It requires improving soil health, providing adequate amounts of macro nutrients – nitrogen, phosphorus and potash – scouting, soil and tissue testing.
“The potential for corn goes far beyond 180 to 220 bushels,” said Ken Hamilton, chief executive officer of Bio Mineral Technologies, based in Logan, Utah. “But it’s not reached through genetics, but management.”
This includes breaking up any compaction, timely planting with soil biology in furrows, seed treatments, nitrogen and micronutrient starters.
He said at V3-V5, the plant is determining the number of rows per cob. At V8-V10, the plant is determining ear length.
Tissue testing throughout the growing cycle will pinpoint the nutrients that are in abundance and which are lacking. These can be added to the plant by foliar applications.
At post-harvest, nitrogen stalk testing will offer a clear picture of what nutrients will be returned to the soil after stover breaks down.
“These plants have a specific diet,” Hamilton said. “They don’t alter the diet based on our ability to provide the nutrients. They simply take what they can get and cut yield.
“So it’s critical we understand what this plant’s diet really is. If we are not in sync with the plant, we are working against it and that is costing us yield and (grain) quality.”