CHICAGO — Hot, dry weather threatens almost a third of Midwest corn and soybean crops over the next 15 days, as high winds flattened fields from Iowa to Ohio this week, a weather forecasting service predicted.
Temperatures will average as much as 12 degrees above normal through July 28 and possibly into early August, increasing damage to cornfields from Kansas to Michigan, according to Commodity Weather Group, a Bethesda, Md.-based forecaster. Drier weather with hotter temperatures increases risks for lower corn and soybean yields.
"The biggest risk for hot temperatures the next two weeks will run from Illinois to the west, including parts of Iowa, Nebraska, Minnesota, Missouri and Kansas," where more than half of the corn will be pollinating, Joel Widenor, Commodity Weather's director of agricultural services, said Wednesday in an interview. "Our latest 16-day to 30-day outlook is also trending warmer," increasing risks for soybeans when they begin setting pods and filling them with beans, he said.
Corn prices have jumped 11 percent since July 1 and soybeans are up 4.2 percent on renewed concern that newly planted crops in the United States, the world's largest grower and exporter, may yield less than the government forecasts. Farmers begin harvesting in the main Midwest growing regions in September and October.
The Department of Agriculture said June 30 that farmers planted almost 53 million acres with corn in Iowa, Illinois, Nebraska, Minnesota, Kansas and Missouri this year, or 58 percent of the total acreage. Soybeans in those six states were sown on more than 39 million acres, or 52 percent of the total, USDA data show.
The current weather pattern is similar to 1983, when planting was delayed by unusually heavy rains and floods, followed by hot, dry spells in July and August that reduced yields, Widenor said. Corn yields fell 28 percent to 81.1 bushels an acre in 1983 from 113.1 bushels in 1982, while soybean yields fell 17 percent, USDA data show.
"This year is looking similar to 1983, but not identical," Widenor said. "We do not think it will be as dry as it was in 1983, but the heat will have a negative impact on crops."
About 500,000 acres, or 0.3 percent of the total U.S. corn and soybean acreage, were affected by 70-mile-an-hour winds associated with a line of thunderstorms July 11, Widenor said. About 275,000 of those acres were damaged, he said.
"The heat the next two weeks will have a greater ability to knock down yields than the isolated wind damage," Widenor said.