Kimberly — Corn growers need to brace themselves for low prices and a probable low margin year in 2017, especially if policy change promises made by the incoming Trump administration are carried out, University of Wisconsin Extension Service agronomist and corn production specialist Joe Lauer told attendees at the recent series of agronomy update meetings.
Lauer referred to President-Elect Donald Trump's statements about rescinding the North American Trade Agreement and not approving the proposed Trans-Pacific Partnership trade agreement. With the inclusion of representatives of the oil industry in Trump's nominations for cabinet positions, the Renewable Fuels Standard that mandates the use of ethanol made from corn in fuels could also be in jeopardy, he added.
Scrapping of the trade agreements would result in “a huge loss of corn exports” while loss of the RFS would greatly reduce the use of corn in producing ethanol, Lauer observed. With those prospects, corn growers need to look at cutting input costs and at choosing hybrids of the proper maturity for their location — especially for corn to be harvested as dry grain, he said.
Corn maturity ratings
On the latter point, the Extension Service has collected many years of data at its field trial plots around the state, Lauer said. Those records, covering 22 years, show appropriate ranges for grain corn of 85 days on the relative maturity chart in northern Wisconsin up to 115 days in the state's southern tier of counties.
Within a data set for 1999 through 2016, the top grain yields at the Arlington research farm in southern Columbia County were achieved with hybrids of a 110-day relative maturity, Lauer reported. For those years at the Marshfield research station, however, the challenges posed by the growing site have not resulted in any correlation for hybrids with 75 to 115 day rated maturities.
At the site near Seymour in northern Outagamie County, the multiple years of data suggest a 108 day maturity for the top grain yield while 107 days is the best choice for the site at rural Valders in Manitowoc County, Lauer pointed out.
But the evaluation of hybrids for corn grain doesn't stop with the yields, Lauer emphasized. He explained that the drying costs — typically 6 cents per bushel at a commercial facility and 3 cents on-farm — must be included in the calculation for best economic return. That would lower the ideal maturity to 104 days in Arlington, 97 days in Seymour and 96 days in Valders.
For the most part, those numbers don't apply if the intended use of the crop is to make silage or for high moisture shelled corn, Lauer noted. Being aware of a corn hybrid's relative maturity is most crucial in the northern areas while growers in southern Wisconsin can expect that every one day difference in maturity translates to a grain yield difference of two bushels per acre, he indicated.
2016 season results
If every growing season were like in 2016, those differences would be far less important because a very lengthy growing season presented only minimal stresses to the corn crop, Lauer observed. He described 2016 as “the season that wouldn't end,” given that a killing freeze didn't strike until late October in the north and the 2nd week of November in the south, well after late developing leaf and plant diseases had already terminated growth in many cases.
As a result, the National Agricultural Statistics Service has estimated a record high corn grain yield of 180 bushels per acre in the state for 2016 — a jump of 16 bushels from 2015, Lauer noted. Even a 104-day maturity hybrid not planted until July 1 yielded 130 bushels of grain per acre.
At the Extension Service plots around the state, all posted average yields of at least 200 bushels per acre, record high yields were set at six sites, each site recorded a 9 to 38 percent increase in grain yields compared to the 10-year average, corn silage yields were up by 10 to 55 percent from the 10-year average at the sites and 17 of the corn silage yields placed in the top 50 in the history of the sites, Lauer said.
New yield records were set at all the plot sites in the north central zone (Valders, Seymour, Marshfield and Chippewa Falls), Lauer continued. He also noted that, once again, multiple seed companies had their hybrids share in the top 10 yields at each site.
Transgenic technology traits
Including 26 in 2016, the Extension Service's plots have evaluated 68 transgenic technology traits of the more than 8,000 that have been registered for corn, Lauer indicated. Comparisons of their performance against one another and the trial average are tabulated every year.
There are yield differences in the groupings of those traits, but Lauer surmised they might be due in large part to the genetic backgrounds of the hybrids into which they were introduced.
One new trait evaluated in 2016 at the plots was the gene for drought tolerance, Lauer disclosed. Although drought was not much of a factor in 2016, he noted 11 of the 14 trials conducted with corn having the drought tolerance trait earned a coveted star rating for grain yields.
Among all the transgenic traits, the drought tolerance one is distinct because it is the first one capable of increasing yields beyond the basic genetics of the hybrid, Lauer explained. For many years, he had been cautioning audiences and readers that the transgenic traits could only protect yields, not increase them.
Conventional hybrids, particularly during times of dim prospects for profit margins, still have a role in corn production, Lauer emphasized. He pointed out that in 2016 several of them again placed in the top 10 for yields at several sites, mainly those at northern locations.
In the plots for 2016, the 309 conventional hybrid entries averaged 7.7 bushels less yield on grain corn compared to the trial averages, Lauer pointed out. For that reason, he advises growers to check the trial data at corn.agronomy.wisc.edu to identify which conventional hybrids are likely to perform the best.
Although Extension Service research has not been extensive on seed treatments for corn, Lauer advocates treating all seeds with one or more of the fungicide treatments. He listed Captan, Maxim, and Apron as “the workhorses” in that category.
In the insecticide category for seed treatments, the findings show that Poncho 1250 is most often a good choice in any combination, Lauer observed. He noted that since 2004 there have been tests of 188 seed treatment formulae in the Wisconsin plots.
Of the 13 treatment products evaluated at seven locations in north central and northern Wisconsin from 2013 to 2015, there was no statistically significant difference in the corn yields, Lauer reported. The only fairly consistent difference at sites such as Chippewa Falls, Marshfield, Seymour and Valders has been a plant population loss of about 6,000 per acre when the seed had not been treated.
For all of Wisconsin, however, the bottom line difference in yields in the plots between seed treated and untreated with an insecticide is only eight bushels per acre, Lauer said. Based on those findings, he concludes that an insecticide treatment is justified only when there is a known infestation of pests that would be controlled.
Growth regulator trials
One product which was tested at 11 trial plots in 2012 and 2016 was a growth regulator with the trade name of Ascend, Lauer reported. It can be applied as a seed treatment, in furrow or as a foliar liquid.
During the drought-affected year of 2012 and the nearly ideal growing year of 2016, the trial results did not show any significant benefit from the product, Lauer said. The greatest differences were tabulated at the irrigated Hancock site. Except for growers who want to try it on a small scale, Lauer does not endorse use of the Ascend product.