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Reduced acreage and lost yield potential for the 2019 corn crop look to increase prices as wet weather continues to cover much of the Corn Belt. The magnitude of the production loss appears set to hit a level similar to a severe drought.

Weakening demand may temper the rally, but the potential of a decline in corn stocks is massive for the 2019-2020 marketing year. Corn prices until recently lagged behind the developing issues with planting. That probably failed to create a large-enough price increase to discourage prevented-plant acres across large areas of the Corn Belt thus far.

The U.S. Department of Agriculture’s March “Prospective Plantings” report indicated intentions to plant 92.8 million acres of corn this year. That’s 3.66 million more acres than planted the previous year. An estimate of actual planted acres arrives with the USDA’s June 28 acreage report. But current planting pace and weather conditions point toward a sizable loss of corn acres.

The release of another round of Market Facilitation Payments may influence corn-planting decisions. Given the uncertainty surrounding payments, the potential for prevented plant acreage exceeding the record 3.6 million acres documented for corn prevent-planting in 2013 appears certain.

The prevented-plant deadline of May 25 for many areas of North Dakota, South Dakota, Nebraska, Missouri and Kansas has passed. Those states in 2013 prevent-planted about 969,000 acres. In those states as of May 19, there were 13.67 million acres of corn that remained unplanted.

The May 31 prevent-plant date for Minnesota, Wisconsin and Iowa passed under very wet conditions. In those three states there were 10.2 million acres that remained unplanted as of the May 19 planting-progress report. Wet weather in the Corn Belt during the past two weeks points toward reduced levels of planting progress as of the May 28 report and an expectation of more than 35 million acres of corn left unplanted.

If one assumes minimal prevented-plant or acreage switching, large areas of the Corn Belt look to plant corn very late in the planting window. Agronomic studies on yield and planting date in Illinois show substantial yield loss when planting after May 20. As planting moves further past May 20, yield loss accelerates. Field trials show a loss of 1.1 bushels per acre per day past May 30.

Whether corn acreage falls out of the supply equation or corn is planted late, expectations should reflect a much smaller crop for 2019 than current USDA projections. Summer weather will determine the magnitude of yield. Yield expectations should focus on a value near trend yield as a best-case scenario. A combination of reduced acreage and reduced yields for the 2019 corn crop appears a prudent assumption at this point, with the potential for substantial production losses. USDA’s current projection of 15.03 billion bushels at a yield of 176 bushels per acre and 92.8 million acres planted is much too high.

The supply of corn for the 2019-20 marketing year will consist of carryover supplies of old-crop corn and the 2019 harvest. The USDA currently projects the carryover of old-crop corn at 2.095 billion bushels.

The prospect of a larger 2018-2019 ending-stocks number is a distinct possibility. Ethanol and export markets indicate weakening demand for corn. Ethanol production decreased during the past few weeks despite poor margins. Weekly production eclipsed a million barrels per day for seven weeks running after reduced production levels in March. The current USDA projection of 5.45 billion bushels of corn used for ethanol production appears attainable, with corn used for ethanol sitting at about 3.83 billion bushels as of May 17.

Corn exports continue to show a slower sales pace than the previous year for the remainder of the marketing year. As of May 23 corn exports sit at about 1.66 billion bushels – 72 percent of the USDA projection of 2.3 billion bushels for the current marketing year. Export sales sit at 372 million bushels through May 16, much less than the 701 million bushels sold at the same time in the previous year.

Lagging sales and the large corn crop in South America provide caution on the current export projection. The USDA projects corn production in Brazil at 3.94 billion bushels and in Argentina at 1.93 billion bushels. About 72 percent of Brazilian corn production is in the second crop, which has had excellent growing conditions. The influence of that sizable second crop on corn exports looks to manifest itself this summer as harvest and shipping commence, with projections of more than 1.18 billion bushels of exports in 2019.

Domestic corn exports should maintain a steady pace into the summer months, but could lead to lesser projected corn exports during the 2018-2019 marketing year. While demand appears to be weakening, the potential crop shortfall points toward much increased corn prices in 2019.

Uncertainty about the size of the 2019 corn crop will continue for the next few months. Corn prices appear set to take on the pattern of a price spike and long tail associated with a crop shortfall. Corn marketing in 2019-2020 should reflect that reality.

Todd Hubbs is an agricultural economist with the University of Illinois-College of Agricultural, Consumer and Environmental Sciences. Visit for more information.