CHICAGO | Mon May 18, 2015 6:05pm BST

Freezing temperatures will threaten emerging corn plants in North Dakota while rains linger this week in the southern U.S. Plains wheat belt, an agricultural meteorologist said Monday.

Light snow fell early Monday in North Dakota, and temperatures on Tuesday were expected to dip to the mid to upper 20s Fahrenheit (minus 4 to minus 2 degrees Celsius) in the central portion of the state.

"At this point it looks like we will see some damage and some need for re-planting in those areas," said David Streit, a meteorologist with the Commodity Weather Group, adding that roughly half the state's corn crop was vulnerable.

North Dakota farmers are expected to plant 2.7 million acres of corn this year, down from 2.8 million last year and far less than the 13.6 million acres projected for top producer Iowa.

In neighboring Minnesota, the No. 4 corn producer, conditions should not get cold enough to threaten crops. Temperatures should moderate after Tuesday.

North Dakota is the biggest U.S. producer of spring wheat, but that crop is hardy enough to withstand the cold, Streit and others said.

MORE RAIN FOR SOUTHERN PLAINS

Farther south, weekend rains soaked portions of Kansas, the top grower of winter wheat, used for bread. Storms dumped up to 4 inches in parts of south-central to northeast Kansas, with lesser amounts in Oklahoma and the Texas Panhandle.

Rains since late April have helped recharge soil moisture in the southern Plains, which has been in the grip of a long-term drought. But the rains are starting to become excessive.
Forecasts call for two more waves of showers in the region this week, raising the risk of yield-robbing diseases and crop quality problems as winter wheat approaches maturity.

"Certainly from a quality standpoint, it's going to start to become a real negative," Streit said.